Re: [time-nuts] UPS for my time rack

[Hal Murray]

gign...@gmail.com said:
> Those traco power units are fantastic. Absolutely great. 

I first encountered power "bricks" 10 or 15 years ago.  They come in various 
sizes.  Full brick, half-brick, and quarter-brick were common when I was 
watching, with the usual blizzard of output voltages.  They are made by many 
vendors.  There is lots of competition on two fronts: efficiency and 
watts/package.

I think the original ones were targeted at phone company applications since 
they ran off 48 V.  (That may have just been the ones I was paying attention 
to.)  Other input voltages are also common.  The input voltage typically has 
a 2:1 range.

The pinouts are reasonably standard.  I don't know if there is an official 
spec or everybody else copies the first company to get something good on the 
market.

-- 
These are my opinions.  I hate spam.



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Re: [time-nuts] UPS for my time rack

[Dave Martindale]

How did you find the units that will act as a UPS, without buying
everything on the market and testing them?

I just checked all of those bricks in our house, and none will do it.
There are a couple of PNY units that do not provide output power until a
button is pressed, and don't charge until input power is connected while in
idle mode.  Then there are Tp-Link and Mophie units that switch on the
output automatically when a load is connected (or perhaps the output is
just always powered), but which disable the output and switch to charge
mode when input power is provided.  None of them seem able to pass through
5V power without discharging.

- Dave

On Tue, Oct 13, 2015 at 2:07 PM, Tom Van Baak  wrote:

>
> Recently, as some of my gear works from 5 VDC, those ~2600 mAh mobile
> phone USB backup power bricks make an excellent mini-UPS. The ideal models
> are those without LEDs or on/off buttons so they discharge and charge/float
> seamlessly without manual intervention, even if fully drained.
>
> Multiple units can be placed in series for additional, if slightly
> inefficient, capacity. A good self-test is:
>
> http://leapsecond.com/images/perpetual-USB-power.jpg
>
> /tvb
>
>
>
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Re: [time-nuts] UPS for my time rack

[Poul-Henning Kamp]

In message <20151013225202.1e70a...@aluminium.mobile.teply.info>, Florian Teply
 writes:

>DC-DC converters with very
>good efficiency exist for quite some time now.

The one I just put in my HP5065A does 60W with 90+% efficiency
in a 2x1x.5 inch package:

http://phk.freebsd.dk/hacks/HP5065A/20150930_dcdc/index.html

>Umm, around here, at least for ham radio operators, it seems many
>standardize now on PowerPole connectors for 12V DC.

They're quite neat, but I wish there were something a little less
heavy-duty for the 1-2 Amp range.

-- 
Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since RFC 956
FreeBSD committer   | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
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Re: [time-nuts] UPS for my time rack

[Eric Scace]

I’ve used Anderson PowerPoles in mixed voltage environments successfully. A 
visual indication can be obtained by using other colors for the connector 
shell; e.g., red for +13 Vdc and blue for +25 Vdc…

One can also re-orient one of the connectors in each pair by 90º or 180º to 
create a physical incompatibility. This takes some care as the cable ends are 
no longer interchangeable, but it does provide protection against connecting to 
the wrong voltage.

— Eric K3NA

> On 2015 Oct 13, at 16:52 , Florian Teply  wrote:
> 
> Am Tue, 13 Oct 2015 18:54:58 +
> schrieb "Poul-Henning Kamp" :
> 
> […snip…]
> Umm, around here, at least for ham radio operators, it seems many
> standardize now on PowerPole connectors for 12V DC. They are pretty
> affordable, running at below 2 Euro for a single pair. Sure, it's not
> as cheap as an USB connector, but they are designed to handle
> significant currents (15, 30, 45 amps which are freely interchangeable,
> versions rated for 75 or 120 amps exist also).
> 
> Now of course if you want to mix voltage levels, things might become a
> bit more complicated, as most 12V equipment doesn't like to be supplied
> with 24 volts, so it might actually not be the brightest idea to use
> identical connectors in such circumstances. Don't ask how I know... ;-)
> 
> Of course, short circuit currents are the same as before, so properly
> rated fuses and/or circuit breakers are a must, but that would be
> recommended for mains powered equipment as well.
> 
> Best regards,
> Florian


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Re: [time-nuts] UPS for my time rack

[Gary Woods]

On Wed, 14 Oct 2015 06:34:39 +, you wrote:

>They're quite neat, but I wish there were something a little less
>heavy-duty for the 1-2 Amp range.

For the small stuff, I use the little round plugs that come in a bunch of
sizes; I've tried to standardize my shack on 5.5X2.5mm for things like a
VLF upconverter and a little broadband amplifier mounted in a diecast box
(Who doesn't love Digi-Key?).  But I still put powerpoles with the smaller
contacts on the other end to run on the shack's 12V bus.

-- 
Gary Woods AKA K2AHC- PGP key on request, or at home.earthlink.net/~garygarlic
Zone 5/4 in upstate New York, 1420' elevation. NY WO G
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Re: [time-nuts] UPS for my time rack

[Neil Schroeder]

Depending on your actual power throughput needs- PTCs can be a challenge as
Bob mentions.  You will have a tough time meeting the power requirements of
a Thunderbolt with many you'll see.   Now efuses (think TPS24/25xxx)  or
mosfets with a controller (think LTC43xx) can be a good choice but don't
hesitate to use a real honest to god fuse that blows out and waits for you
to come replace it if that is what you would need

I personally do as suggested in the thread above to some degree- I do AC to
DC conversion once for all my time and frequency stuff then have batteries
local to important gear and (in older stuff) a diode(s) or (in newer stuff)
a real hotswap controller.  But whenever something is really important
there's whatever fuse is needed.

Finally if you are of the type to be adventuresome -
http://cds.linear.com/docs/en/datasheet/4110fb.pdf  or

- Google for Freescale's, ON Semi's or TI's *offline* UPS Reference
designs.  Yes they invert DC to AC, but you can drive the inverter gates
with a microcontoller's PWM output. meaning no matter how jagged your
utility's wave may be you can create a perfect, beautiful 50 or 60 Hz sine
of your own - devoid of most noise.

NS

On Wed, Oct 14, 2015 at 12:01 AM Bob Camp  wrote:

> Hi
>
> One option for the “fuse” part of the DC supply system are PTC resettable
> fuses. You *do* indeed need to be careful about voltage and current ratings
> on these gizmos. If the only objective is to “not have smoke” when there
> is a short,
> that can reduce the variables to a manageable level. If your wire will
> handle 20A for
> long enough to get the gizmo to limit and your load is typically < 5A
> there are
> parts you can find.
>
> A few cautions:
>
> The trip points are very temperature dependent. If you need to handle -20C
> in the winter
> and +40C in the summer, that will narrow things down quite a bit.
>
> Mounting matters quite a bit. If you go with SMD parts, be careful of
> traces that act as
> heatsinks. This is one case that the part needs to get hot.
>
> There are to many variables on most of the spec sheets to simply pick one
> and move on.
> The only good way to do it is to get several and run repeated tests on
> them Min carry current
> will occur at your highest temperature. Worst case trip will occur at your
> lowest temperature.
>
> Consider that the “carry current” may not be the real limitation.
> Resistance in the supply lead
> of an OCXO is a bad idea. This may limit your current well below the point
> that the fuse actually
> trips.
>
> This sounds like a pretty scary list. To some degree it is. These parts do
> have their place. That
> does not mean they work everywhere and anywhere.
>
> Bob
>
> > On Oct 13, 2015, at 2:54 PM, Poul-Henning Kamp 
> wrote:
> >
> > 
> > In message <4FD0F30EBAEF49609DF207E3EE61C15B@pc52>, "Tom Van Baak"
> writes:
> >
> >
> >> I used to rely on one massive UPS (along with natural gas generator)
> >> for my entire lab. Eventually I found it more reliable and convenient
> >> to have localized power backup. By local I mean backup for a single
> >> shelf, or even a single instrument.
> >
> > The big gain is avoiding the DC->AC conversions.
>
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Re: [time-nuts] UPS for my time rack

[Bob Camp]

Hi

> On Oct 14, 2015, at 2:34 AM, Poul-Henning Kamp  wrote:
> 
> 
> In message <20151013225202.1e70a...@aluminium.mobile.teply.info>, Florian 
> Teply
> writes:
> 
>> DC-DC converters with very
>> good efficiency exist for quite some time now.
> 
> The one I just put in my HP5065A does 60W with 90+% efficiency
> in a 2x1x.5 inch package:
> 
>   http://phk.freebsd.dk/hacks/HP5065A/20150930_dcdc/index.html
> 
>> Umm, around here, at least for ham radio operators, it seems many
>> standardize now on PowerPole connectors for 12V DC.
> 
> They're quite neat, but I wish there were something a little less
> heavy-duty for the 1-2 Amp range.

So far my answer to that has been the coaxial power plug that you see on a lot 
of wall chargers.
Pick a size and have them ship you a bucket full of pre-made cables for next to 
nothing. The cables
with both male and female ends are cheaper than the ones with tinned leads on 
one end (go figure …). 
That makes the “which one do I buy” decision pretty easy. Once they come in and 
you chop them up, a 
bit of quality time with the soldering iron gives you a reasonable inventory of 
power squids to distribute 
your +6, +12 or +24V.

Bob

> 
> -- 
> Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
> p...@freebsd.org | TCP/IP since RFC 956
> FreeBSD committer   | BSD since 4.3-tahoe
> Never attribute to malice what can adequately be explained by incompetence.
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Re: [time-nuts] UPS for my time rack

[Neil Schroeder]

Those traco power units are fantastic. Absolutely great.

For smaller applications Murata makes 3W ones quite similar and Wurth
Electronik is also in that market.

On Wed, Oct 14, 2015 at 12:00 PM Poul-Henning Kamp 
wrote:

> 
> In message <20151013225202.1e70a...@aluminium.mobile.teply.info>, Florian
> Teply
>  writes:
>
> >DC-DC converters with very
> >good efficiency exist for quite some time now.
>
> The one I just put in my HP5065A does 60W with 90+% efficiency
> in a 2x1x.5 inch package:
>
> http://phk.freebsd.dk/hacks/HP5065A/20150930_dcdc/index.html
>
> >Umm, around here, at least for ham radio operators, it seems many
> >standardize now on PowerPole connectors for 12V DC.
>
> They're quite neat, but I wish there were something a little less
> heavy-duty for the 1-2 Amp range.
>
> --
> Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
> p...@freebsd.org | TCP/IP since RFC 956
> FreeBSD committer   | BSD since 4.3-tahoe
> Never attribute to malice what can adequately be explained by incompetence.
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> To unsubscribe, go to
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> and follow the instructions there.
>
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Re: [time-nuts] UPS for my time rack

[Bob Camp]

Hi

One option for the “fuse” part of the DC supply system are PTC resettable 
fuses. You *do* indeed need to be careful about voltage and current ratings 
on these gizmos. If the only objective is to “not have smoke” when there is a 
short, 
that can reduce the variables to a manageable level. If your wire will handle 
20A for 
long enough to get the gizmo to limit and your load is typically < 5A there are 
parts you can find. 

A few cautions: 

The trip points are very temperature dependent. If you need to handle -20C in 
the winter 
and +40C in the summer, that will narrow things down quite a bit. 

Mounting matters quite a bit. If you go with SMD parts, be careful of traces 
that act as
heatsinks. This is one case that the part needs to get hot. 

There are to many variables on most of the spec sheets to simply pick one and 
move on. 
The only good way to do it is to get several and run repeated tests on them Min 
carry current
will occur at your highest temperature. Worst case trip will occur at your 
lowest temperature. 

Consider that the “carry current” may not be the real limitation. Resistance in 
the supply lead 
of an OCXO is a bad idea. This may limit your current well below the point that 
the fuse actually 
trips. 

This sounds like a pretty scary list. To some degree it is. These parts do have 
their place. That
does not mean they work everywhere and anywhere. 

Bob

> On Oct 13, 2015, at 2:54 PM, Poul-Henning Kamp  wrote:
> 
> 
> In message <4FD0F30EBAEF49609DF207E3EE61C15B@pc52>, "Tom Van Baak" writes:
> 
> 
>> I used to rely on one massive UPS (along with natural gas generator)
>> for my entire lab. Eventually I found it more reliable and convenient
>> to have localized power backup. By local I mean backup for a single
>> shelf, or even a single instrument.
> 
> The big gain is avoiding the DC->AC conversions.

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Re: [time-nuts] UPS for my time rack

[Poul-Henning Kamp]

In message <1444701906.379459.408467601.5676d...@webmail.messagingengine.com>, 
Bill Byrom writes:

>Anything can (and will) fail, [...]

The interesting thing is that several sources in that business have
reported to me that about 30-40% of all power related downtime is
caused by Battery, generator and UPS failure, in that order.

Many sites simply have lower uptime after they install UPS systems.

-- 
Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since RFC 956
FreeBSD committer   | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
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Re: [time-nuts] UPS for my time rack

[Poul-Henning Kamp]

In message <4FD0F30EBAEF49609DF207E3EE61C15B@pc52>, "Tom Van Baak" writes:


>I used to rely on one massive UPS (along with natural gas generator)
>for my entire lab. Eventually I found it more reliable and convenient
>to have localized power backup. By local I mean backup for a single
>shelf, or even a single instrument.

The big gain is avoiding the DC->AC conversions.

AC->DC conversions are covered under EnergyStar and similar programmes,
so they're generally 90% efficient or better.

But DC->AC conversions, for instance in inverters and UPS's are not
covered, the argument going that they are only run very seldomly,
and therefore capital cost would be wasted.

In the professional segment, UPS's which require a forklift,
efficiencies are good, in some cases very good, because power costs
money at that scale.

But anyting you can fit into a rack will typically have horrible
losses, the smaller the UPS the worse.  I've personally measured
sub 50% efficiency in one case.

The argument against running stuff on 12 or 24V DC is the short
circuit currents, and the absense of an affordable standarized
connector.

For the short circuit currents the only cure is fuses and caution,
and for connectors there seems to be no hope of a standard - ever.

China forced USB through as the standard for mobile phones, but
despite several valiant attempts nobody has ever managed to get
anything above 5V/5W standardized.

Here's the website of the IEEE WG which came out with a standard
(IEEE 1823:2015) this May:

http://grouper.ieee.org/groups/msc/upamd/

It will cost you $160 to see the full standard, which is a very
good and strong reason why adoption will be slow, and nobody
I've talked to expects it to go anywhere ever.

At the same time USB has come up with 100W power concept
which is not compatible, since IEEE uses CANbus and different
connectors.

I've not heard any rumours that China man nail this one.


-- 
Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since RFC 956
FreeBSD committer   | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
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Re: [time-nuts] UPS for my time rack

[Tom Van Baak]

I found this UPS article fascinating, because it echoed what I eventually found 
in my own lab:

http://www.theplatform.net/2015/03/13/how-this-battery-cut-microsoft-datacenter-costs-by-a-quarter/

I used to rely on one massive UPS (along with natural gas generator) for my 
entire lab. Eventually I found it more reliable and convenient to have 
localized power backup. By local I mean backup for a single shelf, or even a 
single instrument.

Consider that many Rb/Cs standards and even some Qz standards have internal 
batteries. Even if one chooses not to use their internal batteries, most of 
these instruments still feature dual power inputs. In addition to power 
redundancy it also makes it easy to move equipment or cables around without 
power loss. Most importantly, local backup like this avoids the possibility of 
single-point lab-wide power failures.

Recently, as some of my gear works from 5 VDC, those ~2600 mAh mobile phone USB 
backup power bricks make an excellent mini-UPS. The ideal models are those 
without LEDs or on/off buttons so they discharge and charge/float seamlessly 
without manual intervention, even if fully drained.

Multiple units can be placed in series for additional, if slightly inefficient, 
capacity. A good self-test is:

http://leapsecond.com/images/perpetual-USB-power.jpg

/tvb

- Original Message - 
From: "Poul-Henning Kamp" <p...@phk.freebsd.dk>
To: "Discussion of precise time and frequency measurement" 
<time-nuts@febo.com>; "Bill Byrom" <t...@radio.sent.com>
Sent: Monday, October 12, 2015 11:44 PM
Subject: Re: [time-nuts] UPS for my time rack


> 
> In message 
> <1444701906.379459.408467601.5676d...@webmail.messagingengine.com>, 
> Bill Byrom writes:
> 
>>Anything can (and will) fail, [...]
> 
> The interesting thing is that several sources in that business have
> reported to me that about 30-40% of all power related downtime is
> caused by Battery, generator and UPS failure, in that order.
> 
> Many sites simply have lower uptime after they install UPS systems.
> 
> -- 
> Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
> p...@freebsd.org | TCP/IP since RFC 956
> FreeBSD committer   | BSD since 4.3-tahoe
> Never attribute to malice what can adequately be explained by incompetence.

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[time-nuts] UPS for my time rack

[Tim Shoppa]

A winning way to do 12v and 24v wiring up to 45Amps are Anderson Powerpole
connectors. Many sources sell fused distribution panels.

For larger currents (up to 350A) the SB "Storage Battery" series is broadly
used in Forklifts and solar applications

Tim N3QE

On Tuesday, October 13, 2015, Poul-Henning Kamp > wrote:

> 
> In message <4FD0F30EBAEF49609DF207E3EE61C15B@pc52>, "Tom Van Baak" writes:
>
>
> >I used to rely on one massive UPS (along with natural gas generator)
> >for my entire lab. Eventually I found it more reliable and convenient
> >to have localized power backup. By local I mean backup for a single
> >shelf, or even a single instrument.
>
> The big gain is avoiding the DC->AC conversions.
>
> AC->DC conversions are covered under EnergyStar and similar programmes,
> so they're generally 90% efficient or better.
>
> But DC->AC conversions, for instance in inverters and UPS's are not
> covered, the argument going that they are only run very seldomly,
> and therefore capital cost would be wasted.
>
> In the professional segment, UPS's which require a forklift,
> efficiencies are good, in some cases very good, because power costs
> money at that scale.
>
> But anyting you can fit into a rack will typically have horrible
> losses, the smaller the UPS the worse.  I've personally measured
> sub 50% efficiency in one case.
>
> The argument against running stuff on 12 or 24V DC is the short
> circuit currents, and the absense of an affordable standarized
> connector.
>
> For the short circuit currents the only cure is fuses and caution,
> and for connectors there seems to be no hope of a standard - ever.
>
> China forced USB through as the standard for mobile phones, but
> despite several valiant attempts nobody has ever managed to get
> anything above 5V/5W standardized.
>
> Here's the website of the IEEE WG which came out with a standard
> (IEEE 1823:2015) this May:
>
> http://grouper.ieee.org/groups/msc/upamd/
>
> It will cost you $160 to see the full standard, which is a very
> good and strong reason why adoption will be slow, and nobody
> I've talked to expects it to go anywhere ever.
>
> At the same time USB has come up with 100W power concept
> which is not compatible, since IEEE uses CANbus and different
> connectors.
>
> I've not heard any rumours that China man nail this one.
>
>
> --
> Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
> p...@freebsd.org | TCP/IP since RFC 956
> FreeBSD committer   | BSD since 4.3-tahoe
> Never attribute to malice what can adequately be explained by incompetence.
> ___
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>
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Re: [time-nuts] UPS for my time rack

[Mark Spencer]

Sorry for a somewhat Non time nuts posting but this topic seems to have drawn a 
lot of interest.

I found the Microsoft article fascinating.   Thanks for sharing.  

Re DC power.   I've seen some computing equipment that ran from -48 volts DC 
but to expand on the comments from PHK about DC power it never really seemed to 
catch on in the Enterprise space.   The need to deal with actual wiring issues 
vs simply plugging in an AC power cord was a major obstacle in my view, but 
there were others as well in my view.

(Years ago I did a quick assessment of building a data centre that would have 
largely used -48 volt DC power.   We didn't proceed with the project.)

To return to a time nuts focus:
One of the things I like about much of my time nuts gear is that it runs from 
24 Volts D.C.  At this point though the only gear I have powered by my backup 
battery system is gear that already has a backup 24 Volt power connection.   

I've toyed with the idea of constructing a simple change over system to quickly 
switch from the AC line powered supplies to the backup battery system for the 
gear that doesn't have backup power inputs.   

(I briefly considered running the gear from the batteries full time but I'm 
concerned that some equipment really wants to see 24 volts not the 27.5 thru 28 
volts or so that is required to charge the batteries.  My BVA oscillator is a 
particular concern for me in this regard.)





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Sent from my iPhone

> On Oct 13, 2015, at 11:54 AM, Poul-Henning Kamp  wrote:
> 
> 
> In message <4FD0F30EBAEF49609DF207E3EE61C15B@pc52>, "Tom Van Baak" writes:
> 
> 
>> I used to rely on one massive UPS (along with natural gas generator)
>> for my entire lab. Eventually I found it more reliable and convenient
>> to have localized power backup. By local I mean backup for a single
>> shelf, or even a single instrument.
> 
> The big gain is avoiding the DC->AC conversions.
> 
> AC->DC conversions are covered under EnergyStar and similar programmes,
> so they're generally 90% efficient or better.
> 
> But DC->AC conversions, for instance in inverters and UPS's are not
> covered, the argument going that they are only run very seldomly,
> and therefore capital cost would be wasted.
> 
> In the professional segment, UPS's which require a forklift,
> efficiencies are good, in some cases very good, because power costs
> money at that scale.
> 
> But anyting you can fit into a rack will typically have horrible
> losses, the smaller the UPS the worse.  I've personally measured
> sub 50% efficiency in one case.
> 
> The argument against running stuff on 12 or 24V DC is the short
> circuit currents, and the absense of an affordable standarized
> connector.
> 
> For the short circuit currents the only cure is fuses and caution,
> and for connectors there seems to be no hope of a standard - ever.
> 
> China forced USB through as the standard for mobile phones, but
> despite several valiant attempts nobody has ever managed to get
> anything above 5V/5W standardized.
> 
> Here's the website of the IEEE WG which came out with a standard
> (IEEE 1823:2015) this May:
> 
>http://grouper.ieee.org/groups/msc/upamd/
> 
> It will cost you $160 to see the full standard, which is a very
> good and strong reason why adoption will be slow, and nobody
> I've talked to expects it to go anywhere ever.
> 
> At the same time USB has come up with 100W power concept
> which is not compatible, since IEEE uses CANbus and different
> connectors.
> 
> I've not heard any rumours that China man nail this one.
> 
> 
> -- 
> Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
> p...@freebsd.org | TCP/IP since RFC 956
> FreeBSD committer   | BSD since 4.3-tahoe
> Never attribute to malice what can adequately be explained by incompetence.
> ___
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> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> 
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Re: [time-nuts] UPS for my time rack

[Florian Teply]

Am Tue, 13 Oct 2015 18:54:58 +
schrieb "Poul-Henning Kamp" :

> 
> In message <4FD0F30EBAEF49609DF207E3EE61C15B@pc52>, "Tom Van Baak"
> writes:
> 
> 
> >I used to rely on one massive UPS (along with natural gas generator)
> >for my entire lab. Eventually I found it more reliable and convenient
> >to have localized power backup. By local I mean backup for a single
> >shelf, or even a single instrument.
> 
> The big gain is avoiding the DC->AC conversions.
> 
> AC->DC conversions are covered under EnergyStar and similar
> programmes, so they're generally 90% efficient or better.
> 
> But DC->AC conversions, for instance in inverters and UPS's are not
> covered, the argument going that they are only run very seldomly,
> and therefore capital cost would be wasted.
> 
Definitely, avoiding unnecessary conversions is key to achieve good
efficiency. And in most cases equipment actually converts to DC
internally, so converting AC to DC (for the battery), then back into AC
to power the equipment, which in turn converts to DC to power internal
circuitry is bound to be inefficient. DC-DC converters with very
good efficiency exist for quite some time now. I've converted most of
the stuff I regularly use to run off common 12V and/or 48V rails
generated by two "central" power supply blocks.

> 
> The argument against running stuff on 12 or 24V DC is the short
> circuit currents, and the absense of an affordable standarized
> connector.
> 
> For the short circuit currents the only cure is fuses and caution,
> and for connectors there seems to be no hope of a standard - ever.
> 
Umm, around here, at least for ham radio operators, it seems many
standardize now on PowerPole connectors for 12V DC. They are pretty
affordable, running at below 2 Euro for a single pair. Sure, it's not
as cheap as an USB connector, but they are designed to handle
significant currents (15, 30, 45 amps which are freely interchangeable,
versions rated for 75 or 120 amps exist also).

Now of course if you want to mix voltage levels, things might become a
bit more complicated, as most 12V equipment doesn't like to be supplied
with 24 volts, so it might actually not be the brightest idea to use
identical connectors in such circumstances. Don't ask how I know... ;-)

Of course, short circuit currents are the same as before, so properly
rated fuses and/or circuit breakers are a must, but that would be
recommended for mains powered equipment as well.

Best regards,
Florian
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Re: [time-nuts] UPS for my time rack

[Brooke Clarke]

Hi Poul:

I really like Power Pole connectors.  Unlike cigarette lighter plugs and sockets where the spring causes them to 
separate on their own the Power Pole connectors "snap" together.


The Amateur Radio Emergency Services (ARES) used to use car trailer connectors but long ago switched to Power Pole 
connectors in a specific configuration that maintains their Hermaphroditic  
nature.  That's to say unlike conventional electrical extension cords that have a male and female end, in this system 
both ends of the cord are identical.  The ARES configuration is

"Red on right
A reads right"
http://www.prc68.com/I/PowerPole.shtml

The PP15 series plastic shells used for ARES can accept contacts rated at 15, 30 or 45 Amps, so they can handle quite a 
bit of power.

The contacts are also self wiping.

I've come up with a 24 Volt configuration that does NOT mate with the 12 Volt ARES standard, but retains the 
hermaphroditic feature.

I don't like the systems that only change the plastic shell color because they 
mate with the 12 Volt system.
http://www.prc68.com/I/PowerPole.shtml#24VP

There are a number of companies making DC outlet strips and various other power management devices all based on Power 
Pole connectors.

For example: 
http://www.powerwerx.com/powerpole-power-distribution/rigrunner-4005.html

Mail_Attachment --
Have Fun,

Brooke Clarke, N6GCE
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
http://www.prc68.com/I/DietNutrition.html
Poul-Henning Kamp wrote:


In message <4FD0F30EBAEF49609DF207E3EE61C15B@pc52>, "Tom Van Baak" writes:



I used to rely on one massive UPS (along with natural gas generator)
for my entire lab. Eventually I found it more reliable and convenient
to have localized power backup. By local I mean backup for a single
shelf, or even a single instrument.

The big gain is avoiding the DC->AC conversions.

AC->DC conversions are covered under EnergyStar and similar programmes,
so they're generally 90% efficient or better.

But DC->AC conversions, for instance in inverters and UPS's are not
covered, the argument going that they are only run very seldomly,
and therefore capital cost would be wasted.

In the professional segment, UPS's which require a forklift,
efficiencies are good, in some cases very good, because power costs
money at that scale.

But anyting you can fit into a rack will typically have horrible
losses, the smaller the UPS the worse.  I've personally measured
sub 50% efficiency in one case.

The argument against running stuff on 12 or 24V DC is the short
circuit currents, and the absense of an affordable standarized
connector.

For the short circuit currents the only cure is fuses and caution,
and for connectors there seems to be no hope of a standard - ever.

China forced USB through as the standard for mobile phones, but
despite several valiant attempts nobody has ever managed to get
anything above 5V/5W standardized.

Here's the website of the IEEE WG which came out with a standard
(IEEE 1823:2015) this May:

http://grouper.ieee.org/groups/msc/upamd/

It will cost you $160 to see the full standard, which is a very
good and strong reason why adoption will be slow, and nobody
I've talked to expects it to go anywhere ever.

At the same time USB has come up with 100W power concept
which is not compatible, since IEEE uses CANbus and different
connectors.

I've not heard any rumours that China man nail this one.




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Re: [time-nuts] UPS for my time rack

[Brooke Clarke]

Hi Tom:

The Li-Ion 18650 size cells (18mm dia x 650mm long) are used in most laptop computer batteries and Tesla cars because 
they are made in such high volumes.
The referenced article shows a single 18650 cell, but with about 3.7 Volts per cell you need to connect them in series 
and/or parallel to get the typically needed 12 or 24 Volts (and needed amp hours) for backup power.  The big problem is 
these cells can easily catch on fire and/or explode if they are mistreated either during discharge or charge.  To 
prevent that a protection circuit needs to be incorporated for each individual cell.  The easiest way to do that is to 
buy a battery pack with internal protection circuits and matched charger.  Then this can be connected to the external DC 
input on an individual piece of equipment.  For example:

http://www.batteryspace.com/li-ionpacks37-89v.aspx
My first precision oscillator was a rack mount Gibbs 5 MHz standard that I got for a very low price because the internal 
lead acid battery had vented acid fumes which etched away many of the copper PCB traces inside the oven.

http://prc68.com/I/office_equip.html
http://www.prc68.com/I/rack1.html
Mail_Attachment --
Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
http://www.prc68.com/I/DietNutrition.html
Tom Van Baak wrote:

I found this UPS article fascinating, because it echoed what I eventually found 
in my own lab:

http://www.theplatform.net/2015/03/13/how-this-battery-cut-microsoft-datacenter-costs-by-a-quarter/

I used to rely on one massive UPS (along with natural gas generator) for my 
entire lab. Eventually I found it more reliable and convenient to have 
localized power backup. By local I mean backup for a single shelf, or even a 
single instrument.

Consider that many Rb/Cs standards and even some Qz standards have internal 
batteries. Even if one chooses not to use their internal batteries, most of 
these instruments still feature dual power inputs. In addition to power 
redundancy it also makes it easy to move equipment or cables around without 
power loss. Most importantly, local backup like this avoids the possibility of 
single-point lab-wide power failures.

Recently, as some of my gear works from 5 VDC, those ~2600 mAh mobile phone USB 
backup power bricks make an excellent mini-UPS. The ideal models are those 
without LEDs or on/off buttons so they discharge and charge/float seamlessly 
without manual intervention, even if fully drained.

Multiple units can be placed in series for additional, if slightly inefficient, 
capacity. A good self-test is:

http://leapsecond.com/images/perpetual-USB-power.jpg

/tvb

- Original Message -
From: "Poul-Henning Kamp" <p...@phk.freebsd.dk>
To: "Discussion of precise time and frequency measurement" <time-nuts@febo.com>; "Bill 
Byrom" <t...@radio.sent.com>
Sent: Monday, October 12, 2015 11:44 PM
Subject: Re: [time-nuts] UPS for my time rack




In message <1444701906.379459.408467601.5676d...@webmail.messagingengine.com>,
Bill Byrom writes:


Anything can (and will) fail, [...]

The interesting thing is that several sources in that business have
reported to me that about 30-40% of all power related downtime is
caused by Battery, generator and UPS failure, in that order.

Many sites simply have lower uptime after they install UPS systems.

--
Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since RFC 956
FreeBSD committer   | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

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[time-nuts] UPS for my time rack

[Mark Sims]

How could anybody possibly accept/consider/use a VAX/Unix as a solution to any 
real computer problem?  The manual set only takes 3 feet of shelf space.   
Anybody knows that a real (IBM) computer requires 80+ feet of documentation.  
Or so I was once scolded by the management of a Very Large Company...  that 
shortly thereafter had its lunch served to them by a much smaller competitor 
and went belly up.
Somewhat time-nut related...  the project main application needed millisecond 
consistent (not necessarily accurate) time stamps on a world-wide network.  
That was in the pre-gps, pre-fiber, pre-historic before-times.  I don't think 
that they ever quite got there.



  
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Re: [time-nuts] UPS for my time rack

[Bill Hawkins]

My apologies in advance for further putting tension on this OT thread,
but one of the great stories from the early days of Usenet concerned a
really large UPS system for a data center. In the late 80s the Digital
Equipment Corp VAX computer was among the most powerful you could buy.
If you can accept that amount of time travel, follow this link:

http://www.hactrn.net/sra/vaxen.html

or Google "vaxen immortal power"

The reference to October 19, 1987, is to the first computer failure to
have a major effect on the stock market.

Enjoy, as they say

Bill Hawkins 

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Re: [time-nuts] UPS for my time rack

[Jim Sanford]

Where I live, there are two problems.  Frequent long outages. Solved 
with a natural gas standby generator, which has run several times in 
anger for extended periods since installed.  (Vulnerable supply, low 
priority for restoration.)


The bigger problem is transients.  On a good night, my computer UPS 
activates at least once an hour.  SOmetimes you can see the lights 
blink, some times not.


In the last 6 months, I have had problems with a UPS (recovered by 
extended shutdown), an Astron Power supply for amateur radio equipment, 
a spectrum analyzer, two signal generators, a network analyzer, and an 
oscilloscope.  All were power supply failures, not all repairable.  My 
lab is now protected from the power company by a SmartUPS 2200NET.


I expect the grid to get /less/ reliable.
-- In 2007, DOE published a grid study which said there did not 
exist sufficient generation capacity over load to maintain grid 
stability.  Insufficient additional generation was booked for 
construction, so they predicted widespread rotating blackouts by 2010.
-- The 2008 recession greatly suppressed aggregate load, which is 
probably why the rotating blackouts did not happen.  I read recently 
that demand has not yet recovered above the suppressed levels following 
the precipitous drop in 2008.  (Which generates interesting other 
questions . . . .)
-- I have lost track of the number of GigaWatts of generation which 
has been shut down.


If the load ever recovers . . ..

Good luck!

Jim
wb4...@amsast.org


On 10/11/2015 9:05 AM, Bob Camp wrote:

Hi

Unless you live in an unusual location, long term power outages are going to be 
pretty
rare. At the house I’m now in, we had a high voltage feed that was on it’s last 
legs. We
had short outages on a “many times a week” basis if the wind was blowing at 
all. We had
rare outages in the > 5 minute range. The short / frequent blip stuff is what 
most light weight UPS’s
are designed to handle. Not everybody has this problem. I no longer have it, 
they
ripped out 10 miles of old feeder and the new one works fine.

Indeed there are locations that experience multi hour outages on a fairly 
regular basis.
The combination of bars closing late on Saturday and a long straight road with 
an abrupt
turn in it was particularly hard on a feed line I once had to cope with. In 
that case gas turbine
generators were the answer.

If you have a case where long outages are common, rotary machines are often the 
better
answer than batteries. In the case above, the power company was the one footing 
the bill
for the gear. Fair in this case since they were the ones that *could* have 
moved the line.

If a > 10 minute outage is a “less than once a year” sort of thing, and OCXO’s 
are your only concern,
let them shut down. The net impact to your lab will be relatively small. The 
cost to fix the problem will
be relatively large. Short blips often, are well worth fixing.

The hidden issue with running a UPS is the relatively short life of the 
batteries.
Sealed lead acid is low cost up front, but they simply do not last when charged 
the way
a typical UPS charges them. Before you go into “can’t be true” mode … plug a 
100W light
bulb  load into your UPS and see how long it runs. Battery still *shows* as 
good on the indicator.
Gizmo only runs for 1/4 the time it should … h …. It’s very common to go 
into these
projects with a  reasonable budget, and then find out that the budget to keep 
it going is
not quite so generous.

Bob




On Oct 11, 2015, at 4:57 AM, Kasper Pedersen  wrote:

On 10/11/2015 12:07 AM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote:

Essentially the charging circuits are not designed to run as long as needed
to charge big batteries. Even on ones designed for external batteries,
there's a recommended limit on the size of them. So if you think you might
want to increase runtime by adding some batteries, buy one designed for
that service.

I have gone down that route, so I have some real data to share:

My (soon to be replaced) backup is an old back-ups CS 500, with a
rewired battery pack out of an RT3000 UPS. So instead of 7Ah, the UPS
has 40Ah. With plenty of fuses.

When charging the standard 7Ah battery, the UPS delivers about 0.7A
(from memory) for many hours, and sits at about 14C above ambient.

When charging the 40Ah, the current is the same, the temperature is the
same, just for longer, as it should be, since the thermal time constant
is much shorter than the time it takes to charge the 7Ah.

Where this has problems is during discharge:
I have about 55W load on it, which in turn is at least 5A on the
battery. After 2 hours a timer in the UPS shuts it off, regardless of
battery voltage.
Also, if you run the UPS at high load where the standard battery lasts
shorter than the thermal time constant, then there might well be trouble.



The replacement, a back-ups pro 1500 behaves differently.
It has support for external battery packs, and 

Re: [time-nuts] UPS for my time rack

[Kasper Pedersen]

On 10/11/2015 12:07 AM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote:
> Essentially the charging circuits are not designed to run as long as needed
> to charge big batteries. Even on ones designed for external batteries,
> there's a recommended limit on the size of them. So if you think you might
> want to increase runtime by adding some batteries, buy one designed for
> that service.

I have gone down that route, so I have some real data to share:

My (soon to be replaced) backup is an old back-ups CS 500, with a
rewired battery pack out of an RT3000 UPS. So instead of 7Ah, the UPS
has 40Ah. With plenty of fuses.

When charging the standard 7Ah battery, the UPS delivers about 0.7A
(from memory) for many hours, and sits at about 14C above ambient.

When charging the 40Ah, the current is the same, the temperature is the
same, just for longer, as it should be, since the thermal time constant
is much shorter than the time it takes to charge the 7Ah.

Where this has problems is during discharge:
I have about 55W load on it, which in turn is at least 5A on the
battery. After 2 hours a timer in the UPS shuts it off, regardless of
battery voltage.
Also, if you run the UPS at high load where the standard battery lasts
shorter than the thermal time constant, then there might well be trouble.



The replacement, a back-ups pro 1500 behaves differently.
It has support for external battery packs, and will happily run for at
least 5 hours, even when the external-pack-present signal is not connected.
The external-pack-present signal does make a difference when charging;
Without it, it charges at 0.7A. with it, it charges at 1.5A, and the fan
is on continuously.


/Kasper Pedersen

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Re: [time-nuts] UPS for my time rack

[Ben Hall]

Good morning all,

On 10/10/2015 5:07 PM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote:

I was thinking of doing the same a while back, and intended getting a UPS
and adding a large external battery pack, so if the mains failed late at
night, I could run the GPS receiver and a few other things overnight, and
consider starting the generator in the morning.  I contacted a dealer on
eBay, who specilaises in UPSs. He told me that the smaller units with built
in batteries will die if you put large external batteries on them.


Years ago, I used to work at a place that would give me all their 
cast-off computer parts, including old UPS'.  I've taken probably opened 
up about 20 of them, from various manufacturers.


The problem is that most don't have good heat-sinking on the power 
transistors.  One unit of a brand I can't remember, all it had for a 
heat sink was an aluminum bar!  Clearly, it was only designed to be run 
for a small length of time.


(It's the same case for the transformers - on several removed 
transformers, I've tried to use them backwards to get 12 VAC from 120 
VAC, and they overheat quickly at more than 50% load.)


If you add external batteries, likely you will overheat and fry the 
electronics as they get far hotter than they ever intended.


thanks much and 73,
ben, kd5byb

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Re: [time-nuts] UPS for my time rack

[Bob Camp]

Hi

Unless you live in an unusual location, long term power outages are going to be 
pretty 
rare. At the house I’m now in, we had a high voltage feed that was on it’s last 
legs. We
had short outages on a “many times a week” basis if the wind was blowing at 
all. We had
rare outages in the > 5 minute range. The short / frequent blip stuff is what 
most light weight UPS’s
are designed to handle. Not everybody has this problem. I no longer have it, 
they 
ripped out 10 miles of old feeder and the new one works fine. 

Indeed there are locations that experience multi hour outages on a fairly 
regular basis. 
The combination of bars closing late on Saturday and a long straight road with 
an abrupt
turn in it was particularly hard on a feed line I once had to cope with. In 
that case gas turbine
generators were the answer. 

If you have a case where long outages are common, rotary machines are often the 
better 
answer than batteries. In the case above, the power company was the one footing 
the bill
for the gear. Fair in this case since they were the ones that *could* have 
moved the line. 

If a > 10 minute outage is a “less than once a year” sort of thing, and OCXO’s 
are your only concern, 
let them shut down. The net impact to your lab will be relatively small. The 
cost to fix the problem will
be relatively large. Short blips often, are well worth fixing. 

The hidden issue with running a UPS is the relatively short life of the 
batteries.
Sealed lead acid is low cost up front, but they simply do not last when charged 
the way
a typical UPS charges them. Before you go into “can’t be true” mode … plug a 
100W light 
bulb  load into your UPS and see how long it runs. Battery still *shows* as 
good on the indicator.
Gizmo only runs for 1/4 the time it should … h …. It’s very common to go 
into these
projects with a  reasonable budget, and then find out that the budget to keep 
it going is 
not quite so generous.

Bob



> On Oct 11, 2015, at 4:57 AM, Kasper Pedersen  wrote:
> 
> On 10/11/2015 12:07 AM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote:
>> Essentially the charging circuits are not designed to run as long as needed
>> to charge big batteries. Even on ones designed for external batteries,
>> there's a recommended limit on the size of them. So if you think you might
>> want to increase runtime by adding some batteries, buy one designed for
>> that service.
> 
> I have gone down that route, so I have some real data to share:
> 
> My (soon to be replaced) backup is an old back-ups CS 500, with a
> rewired battery pack out of an RT3000 UPS. So instead of 7Ah, the UPS
> has 40Ah. With plenty of fuses.
> 
> When charging the standard 7Ah battery, the UPS delivers about 0.7A
> (from memory) for many hours, and sits at about 14C above ambient.
> 
> When charging the 40Ah, the current is the same, the temperature is the
> same, just for longer, as it should be, since the thermal time constant
> is much shorter than the time it takes to charge the 7Ah.
> 
> Where this has problems is during discharge:
> I have about 55W load on it, which in turn is at least 5A on the
> battery. After 2 hours a timer in the UPS shuts it off, regardless of
> battery voltage.
> Also, if you run the UPS at high load where the standard battery lasts
> shorter than the thermal time constant, then there might well be trouble.
> 
> 
> 
> The replacement, a back-ups pro 1500 behaves differently.
> It has support for external battery packs, and will happily run for at
> least 5 hours, even when the external-pack-present signal is not connected.
> The external-pack-present signal does make a difference when charging;
> Without it, it charges at 0.7A. with it, it charges at 1.5A, and the fan
> is on continuously.
> 
> 
> /Kasper Pedersen
> 
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Re: [time-nuts] UPS for my time rack

[Bob Benward]

Dave, 
You could use a 120V relay and switch the high capacity battery from its own
charger to the battery pack in the UPS.  When power comes back, the relay
automatically switches the battery out and back to its own charger.

Bob

>>> -Original Message-
>>> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Dr.
>>> David Kirkby (Kirkby Microwave Ltd)
>>> Sent: Saturday, October 10, 2015 6:07 PM
>>> To: Discussion of precise time and frequency measurement
>>> Subject: Re: [time-nuts] UPS for my time rack
>>> 
>>> On 10 October 2015 at 14:20, Chris Waldrup <kd4...@gmail.com> wrote:
>>> 
>>> > Hi,
>>> >
>>> >
>>> > I have decided I'd like to get a UPS to put on the rack containing my
>>> > Thunderbolt, the laptop that runs Lady Heather, and frequency counter.
>>> >
>>> 
>>> There's one issue with them that I don't see anyone mention.
>>> 
>>> I was thinking of doing the same a while back, and intended getting a
UPS
>>> and adding a large external battery pack, so if the mains failed late at
night, I
>>> could run the GPS receiver and a few other things overnight, and
consider
>>> starting the generator in the morning.  I contacted a dealer on eBay,
who
>>> specilaises in UPSs. He told me that the smaller units with built in
batteries
>>> will die if you put large external batteries on them.
>>> Essentially the charging circuits are not designed to run as long as
needed to
>>> charge big batteries. Even on ones designed for external batteries,
there's a
>>> recommended limit on the size of them. So if you think you might want to
>>> increase runtime by adding some batteries, buy one designed for that
service.
>>> 
>>> I've had two here which were HP/Compaq 5 kW units. These were different
>>> to the normal, in that the batteries added up to over 300 V, so could
produce
>>> 240 VAC with no need to step it up. Both these blew up on me, for
reasons I
>>> never worked out. The load was never anywhere near 5 kW.
>>> 
>>> Lots of people mention sine wave. Of course, if you keen enough, you
could
>>> make a class A amplifier and sine wave oscillator. The problem is that
the
>>> pure sine wave inverters tend to be very inefficient.
>>> 
>>> As with most things, there are a lot of things to balance - runtime,
cost,
>>> quality of output, audio noise, RFI  etc etc.
>>> 
>>> Dave
>>> ___
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>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>>> -
>>> No virus found in this message.
>>> Checked by AVG - www.avg.com
>>> Version: 2015.0.6140 / Virus Database: 4435/10788 - Release Date:
>>> 10/09/15

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Re: [time-nuts] UPS for my time rack

[Bob Camp]

Hi

If your problem is transients, from lousy power companies or from lighting on 
your power line, there are ways to address that. 
High voltage at the service line into the building should be fixed at the point 
the line comes in. If you don’t, then you get into
all sorts of neat “transient went here, then there, then nuked the gizmo”. For 
things like time or frequency distribution this 
is a very real thing. The power to one set of gear may / may not be on the same 
UPS as the power to another set of gear.

The best answer is a whole house protection device. These can range from < $100 
at your big box store to > $1K. They can be 
a wire it in on a spare breaker or a call out a pro sort of thing. A lot 
depends on just how bad your problem is. The net effect is that 
your line is fully clamped to local ground at the panel. The phases are both 
clamped to a level that should not affect properly 
designed gear that’s in good condition. There is always a tradeoff between how 
tight to clamp and how fast the gizmo wears out. 
There is the usual  “get what you pay for” in terms of knowing the current 
degree of wear out of the device. 

The alternative is to get your entire lab (and all the devices that feed it) 
onto a good isolation transformer. . Everything then ties to 
a single “lab ground”. What ever bounce you get is now all on everything at 
once. Each time I’ve done this, keeping all the standard 
lines, antenna feeds, ethernet cables, GPIB cables, cable TV feeds, and the 
rest of it correct has become impossible after a year or two. 
There’s just to much going all over the place. 

We are already more than just a bit  off topic for this list. There is another 
twist this can take, that heads over to talking to 
your power company and the people who regulate it. I have seen that work (as in 
the nice new line that feeds this side of town). 

Bob


> On Oct 11, 2015, at 10:44 AM, Jim Sanford  wrote:
> 
> Where I live, there are two problems.  Frequent long outages. Solved with a 
> natural gas standby generator, which has run several times in anger for 
> extended periods since installed.  (Vulnerable supply, low priority for 
> restoration.)
> 
> The bigger problem is transients.  On a good night, my computer UPS activates 
> at least once an hour.  SOmetimes you can see the lights blink, some times 
> not.
> 
> In the last 6 months, I have had problems with a UPS (recovered by extended 
> shutdown), an Astron Power supply for amateur radio equipment, a spectrum 
> analyzer, two signal generators, a network analyzer, and an oscilloscope.  
> All were power supply failures, not all repairable.  My lab is now protected 
> from the power company by a SmartUPS 2200NET.
> 
> I expect the grid to get /less/ reliable.
>-- In 2007, DOE published a grid study which said there did not exist 
> sufficient generation capacity over load to maintain grid stability.  
> Insufficient additional generation was booked for construction, so they 
> predicted widespread rotating blackouts by 2010.
>-- The 2008 recession greatly suppressed aggregate load, which is probably 
> why the rotating blackouts did not happen.  I read recently that demand has 
> not yet recovered above the suppressed levels following the precipitous drop 
> in 2008.  (Which generates interesting other questions . . . .)
>-- I have lost track of the number of GigaWatts of generation which has 
> been shut down.
> 
> If the load ever recovers . . ..
> 
> Good luck!
> 
> Jim
> wb4...@amsast.org
> 
> 
> On 10/11/2015 9:05 AM, Bob Camp wrote:
>> Hi
>> 
>> Unless you live in an unusual location, long term power outages are going to 
>> be pretty
>> rare. At the house I’m now in, we had a high voltage feed that was on it’s 
>> last legs. We
>> had short outages on a “many times a week” basis if the wind was blowing at 
>> all. We had
>> rare outages in the > 5 minute range. The short / frequent blip stuff is 
>> what most light weight UPS’s
>> are designed to handle. Not everybody has this problem. I no longer have it, 
>> they
>> ripped out 10 miles of old feeder and the new one works fine.
>> 
>> Indeed there are locations that experience multi hour outages on a fairly 
>> regular basis.
>> The combination of bars closing late on Saturday and a long straight road 
>> with an abrupt
>> turn in it was particularly hard on a feed line I once had to cope with. In 
>> that case gas turbine
>> generators were the answer.
>> 
>> If you have a case where long outages are common, rotary machines are often 
>> the better
>> answer than batteries. In the case above, the power company was the one 
>> footing the bill
>> for the gear. Fair in this case since they were the ones that *could* have 
>> moved the line.
>> 
>> If a > 10 minute outage is a “less than once a year” sort of thing, and 
>> OCXO’s are your only concern,
>> let them shut down. The net impact to your lab will be relatively small. The 
>> cost to fix the problem 

Re: [time-nuts] UPS for my time rack

[Jim Sanford]

Did the transient suppressors, too.

A few years ago in a severe winter storm, after we got the neighbor's 
house on generator, his furnace still wouldn't work -- furnace brain 
fried.  Took the repair guy 4 hours to make 20 minute trip . . . . my 
surge suppressors went in a week later.


One thing I left out of my earlier post:  ANYTHING I care about is on a UPS.

Good luck!

Jim


On 10/11/2015 12:24 PM, Bob Camp wrote:

Hi

If your problem is transients, from lousy power companies or from lighting on 
your power line, there are ways to address that.
High voltage at the service line into the building should be fixed at the point 
the line comes in. If you don’t, then you get into
all sorts of neat “transient went here, then there, then nuked the gizmo”. For 
things like time or frequency distribution this
is a very real thing. The power to one set of gear may / may not be on the same 
UPS as the power to another set of gear.

The best answer is a whole house protection device. These can range from < $100 at 
your big box store to > $1K. They can be
a wire it in on a spare breaker or a call out a pro sort of thing. A lot 
depends on just how bad your problem is. The net effect is that
your line is fully clamped to local ground at the panel. The phases are both 
clamped to a level that should not affect properly
designed gear that’s in good condition. There is always a tradeoff between how 
tight to clamp and how fast the gizmo wears out.
There is the usual  “get what you pay for” in terms of knowing the current 
degree of wear out of the device.

The alternative is to get your entire lab (and all the devices that feed it) 
onto a good isolation transformer. . Everything then ties to
a single “lab ground”. What ever bounce you get is now all on everything at 
once. Each time I’ve done this, keeping all the standard
lines, antenna feeds, ethernet cables, GPIB cables, cable TV feeds, and the 
rest of it correct has become impossible after a year or two.
There’s just to much going all over the place.

We are already more than just a bit  off topic for this list. There is another 
twist this can take, that heads over to talking to
your power company and the people who regulate it. I have seen that work (as in 
the nice new line that feeds this side of town).

Bob



On Oct 11, 2015, at 10:44 AM, Jim Sanford  wrote:

Where I live, there are two problems.  Frequent long outages. Solved with a 
natural gas standby generator, which has run several times in anger for 
extended periods since installed.  (Vulnerable supply, low priority for 
restoration.)

The bigger problem is transients.  On a good night, my computer UPS activates 
at least once an hour.  SOmetimes you can see the lights blink, some times not.

In the last 6 months, I have had problems with a UPS (recovered by extended 
shutdown), an Astron Power supply for amateur radio equipment, a spectrum 
analyzer, two signal generators, a network analyzer, and an oscilloscope.  All 
were power supply failures, not all repairable.  My lab is now protected from 
the power company by a SmartUPS 2200NET.

I expect the grid to get /less/ reliable.
-- In 2007, DOE published a grid study which said there did not exist 
sufficient generation capacity over load to maintain grid stability.  
Insufficient additional generation was booked for construction, so they 
predicted widespread rotating blackouts by 2010.
-- The 2008 recession greatly suppressed aggregate load, which is probably 
why the rotating blackouts did not happen.  I read recently that demand has not 
yet recovered above the suppressed levels following the precipitous drop in 
2008.  (Which generates interesting other questions . . . .)
-- I have lost track of the number of GigaWatts of generation which has 
been shut down.

If the load ever recovers . . ..

Good luck!

Jim
wb4...@amsast.org


On 10/11/2015 9:05 AM, Bob Camp wrote:

Hi

Unless you live in an unusual location, long term power outages are going to be 
pretty
rare. At the house I’m now in, we had a high voltage feed that was on it’s last 
legs. We
had short outages on a “many times a week” basis if the wind was blowing at 
all. We had
rare outages in the > 5 minute range. The short / frequent blip stuff is what 
most light weight UPS’s
are designed to handle. Not everybody has this problem. I no longer have it, 
they
ripped out 10 miles of old feeder and the new one works fine.

Indeed there are locations that experience multi hour outages on a fairly 
regular basis.
The combination of bars closing late on Saturday and a long straight road with 
an abrupt
turn in it was particularly hard on a feed line I once had to cope with. In 
that case gas turbine
generators were the answer.

If you have a case where long outages are common, rotary machines are often the 
better
answer than batteries. In the case above, the power company was the one footing 
the bill
for the gear. Fair in this case since they were the 

Re: [time-nuts] UPS for my time rack

[Mark Spencer]

I've also seen inverter systems that are designed for stand by power use in 
service at commercial sites in third world countries.  Within reason they 
basically let you run what ever reasonable arrangement of rechargeable lead 
acid based batteries you want that will supply the required voltage and 
current.  They handle the conversion of dc to ac and the switch over from 
commercial to inverter power.   They usually also feature a basic battery 
charger with settings to charge various types of batteries (ie, gel or 
conventional lead acid.)

Typically I've seen them used with a number of automotive style batteries.

The users would need to sort out the necessary cables, fuses, batteries, deal 
with safety considerations etc.

I've never seen these devices in Canada or the U.S.  Sort of a value engineered 
UPS system for price conscious markets.  Might be a nice starting point for 
those who want to role their own system and can deal with the safety aspects of 
this.   I'm not sure what the transfer time from utility to inverter power 
would be.

In the U.S. and Canada the typical practice seems to be to use packaged UPS 
systems that include their own batteries.  


Sent from my iPhone

> On Oct 11, 2015, at 10:36 AM, Bob Benward <rbenw...@verizon.net> wrote:
> 
> Dave, 
> You could use a 120V relay and switch the high capacity battery from its own
> charger to the battery pack in the UPS.  When power comes back, the relay
> automatically switches the battery out and back to its own charger.
> 
> Bob
> 
>>>> -Original Message-
>>>> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Dr.
>>>> David Kirkby (Kirkby Microwave Ltd)
>>>> Sent: Saturday, October 10, 2015 6:07 PM
>>>> To: Discussion of precise time and frequency measurement
>>>> Subject: Re: [time-nuts] UPS for my time rack
>>>> 
>>>>> On 10 October 2015 at 14:20, Chris Waldrup <kd4...@gmail.com> wrote:
>>>>> 
>>>>> Hi,
>>>>> 
>>>>> 
>>>>> I have decided I'd like to get a UPS to put on the rack containing my
>>>>> Thunderbolt, the laptop that runs Lady Heather, and frequency counter.
>>>> 
>>>> There's one issue with them that I don't see anyone mention.
>>>> 
>>>> I was thinking of doing the same a while back, and intended getting a
> UPS
>>>> and adding a large external battery pack, so if the mains failed late at
> night, I
>>>> could run the GPS receiver and a few other things overnight, and
> consider
>>>> starting the generator in the morning.  I contacted a dealer on eBay,
> who
>>>> specilaises in UPSs. He told me that the smaller units with built in
> batteries
>>>> will die if you put large external batteries on them.
>>>> Essentially the charging circuits are not designed to run as long as
> needed to
>>>> charge big batteries. Even on ones designed for external batteries,
> there's a
>>>> recommended limit on the size of them. So if you think you might want to
>>>> increase runtime by adding some batteries, buy one designed for that
> service.
>>>> 
>>>> I've had two here which were HP/Compaq 5 kW units. These were different
>>>> to the normal, in that the batteries added up to over 300 V, so could
> produce
>>>> 240 VAC with no need to step it up. Both these blew up on me, for
> reasons I
>>>> never worked out. The load was never anywhere near 5 kW.
>>>> 
>>>> Lots of people mention sine wave. Of course, if you keen enough, you
> could
>>>> make a class A amplifier and sine wave oscillator. The problem is that
> the
>>>> pure sine wave inverters tend to be very inefficient.
>>>> 
>>>> As with most things, there are a lot of things to balance - runtime,
> cost,
>>>> quality of output, audio noise, RFI  etc etc.
>>>> 
>>>> Dave
>>>> ___
>>>> time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>>> and follow the instructions there.
>>>> -
>>>> No virus found in this message.
>>>> Checked by AVG - www.avg.com
>>>> Version: 2015.0.6140 / Virus Database: 4435/10788 - Release Date:
>>>> 10/09/15
> 
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Re: [time-nuts] UPS for my time rack

[Mark Spencer]

Yes this is a complex topic.   At one point in my career when I was responsible 
for the up time of several data centres for a high tech firm I had an 
Electrical Engineer on my team to (amongst other roles) work thru the various 
issues pertaining to UPS systems.   I recall there were significant differences 
between the various UPS designs.

Getting out of high tech and into an industry where data centres were out 
sourced was a nice change for me (:

To relate this to time nuts, those of us looking at making significant 
investments in this type of equipment would do well to seek out the advice of 
those who are knowledgable.

Sent from my iPhone

> On Oct 10, 2015, at 7:51 AM, Bob Camp  wrote:
> 
> Hi
> 
> All of the UPS vendors these days make a wide range of products. They range 
> from 
> low cost to mighty expensive. They also range a bit in terms of performance. 
> Finding out
> exactly what this or that model *does* do can be a major pain. The marketing 
> guys apparently
> don’t want you to figure out that the low cost gizmo does not have all the 
> performance 
> of the one that costs 5 times as much. 
> 
> First thing to avoid - the pure square wave output versions. These may or may 
> not
> generate RFI in this or that UHF band. They will take out big chunks of HF 
> and mess up 10 MHz
> distribution. I suspect that the filters on some are better than the filters 
> on others. The bigger issue
> is that they do not play nice with modern power factor corrected power 
> supplies. These supplies 
> seem to expect a sine wave and a (possibly ringing) square wave may get them 
> confused.
> 
> Next thing to avoid - The stepped square wave / modified square wave 
> versions. Theses aren’t 
> quite as bad as the centuries old square wave units. It’s more likely you 
> will find these than a 
> pure square. They still have the same issues on RFI. They may or may not 
> antagonize a PFC 
> supply to the same extent. 
> 
> The target is a “pure sine wave” output. That keeps a PFC supply happy. As 
> with any verbal spec, 
> “pure” likely has a few qualifiers on it. It’s not guaranteed to take out the 
> RFI. It at least will reduce 
> the spikes on your 1 pps lines. If you look at the output on a ’scope the 
> waveform at least *looks* like
> a sine wave. 
> 
> All of these gizmos run a switcher in the “few hundred KHz” range to generate 
> the output. They run 
> a similar switcher to charge the battery. None of them are compatible with an 
> indoor antenna in the same
> room trying to listen to MF. None of the ones I have tried are nasty enough 
> to bother GPS, either indoor or
> outdoor. Put another way, I’ve had more trouble from LED lights than from 
> sine wave UPS’s. 
> 
> Cyber Power (via Amazon) seems to make some pretty good stuff at a price 
> point a bit below APC. As
> with everybody else, it’s a pain to figure out what’s what. Are you after a 
> “big” rack mount unit (as in $500
> and up) or something smaller?
> 
> Bob 
> 
> 
>> On Oct 10, 2015, at 9:20 AM, Chris Waldrup  wrote:
>> 
>> Hi,
>> 
>> 
>> I have decided I'd like to get a UPS to put on the rack containing my 
>> Thunderbolt, the laptop that runs Lady Heather, and frequency counter. 
>> Has anyone had bad experience noise wise with the APC brand units like are 
>> available on Amazon and at Staples? I'd like to get one that doesn't 
>> generate lots of RFI. Thank you. 
>> 
>> 
>> Chris
>> KD4PBJ
>> 
>> —
>> Sent from Mailbox
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Re: [time-nuts] UPS for my time rack

[Mark Spencer]

I'm fortunate that several of pieces of my time nuts gear (including two of my 
ocxo's) feature backup 24 volt dc power inputs.   They were the only things in 
my house that stayed running during a recent 2 day power outage while I was 
away.

I have two large 12 volt gel cells in series that I re charge from time to time 
with a power supply via a blocking diode.

I agree about the importance of the fusing.  I've also found it's easy to buy 
fuses rated to work on 12 and 24 volt dc systems, fuses for 48 volt and higher 
dc systems are harder to find.

I also bolt the fuses directly to the battery terminals.

Sent from my iPhone

> On Oct 10, 2015, at 9:31 AM, Alex Pummer  wrote:
> 
> for a very similar application I am using a solar panel to charge the 
> battery, but I have a vented NiFe battery, which is not sensitive of over 
> charging or deep discharging, and has almost unlimited life time -- I have 
> seen some in forklifts which were 60 years old and working...
> 73
> KJ6UHN
> Alex
> 
> 
> 
>> On 10/10/2015 7:14 AM, Poul-Henning Kamp wrote:
>> 
>> In message <183218108.6a07c91c@Nodemailer>, "Chris Waldrup" writes:
>> 
>> 
>>> Has anyone had bad experience noise wise with the APC brand units
>>> like are available on Amazon and at Staples? I'd like to get one
>>> that doesn't generate lots of RFI. Thank you.
>> Then don't.
>> 
>> Instead get 12 or 24 Volt sealed lead-acid batteries and a good
>> float-charger, and run your stuff from that.
>> 
>> You avoid a lot of conversion losses, and you get to decide what
>> quality batteries you want (As opposed to "the cheapest we can get
>> away with") and you get to decide how long hold-up time you want.
>> 
>> The important tricks are:
>> 
>>   1. ATO Fuse *RIGHT NEXT TO THE BATTERY*.  Not a meter away, but
>>  quite literally bolted right onto the terminal.
>> 
>>   2. Don't buy a shit charger, it will cost you battery life.
>> 
>>   3. Suitably sized fuse/polyfuses on all loads.
>> 
>>   4. Either put 0.010 Ohm current shunts in all over the place
>>  or buy a 1mA resolution clamp meter and prepare the wiring
>>  for measurement.
>> 
>> And that's it really...
>> 
>> I run all the always-on stuff in my lab from two 12V/105Ah telco-grade
>> sealed lead-acid batteries, and I'll never look back.
>> 
>> Presenty the load is 6.7A @ 24V, and that powers my ADSL lines,
>> firewalls (soekris), home server (ITX with mini-box.com PSU),
>> emergency lights (LED strips), GPS, GPSDO, HP5065 etc. etc.
> 
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Re: [time-nuts] UPS for my time rack

[Jim Harman]

On Sat, Oct 10, 2015 at 9:20 AM, Chris Waldrup  wrote:

> Has anyone had bad experience noise wise with the APC brand units like are
> available on Amazon and at Staples? I'd like to get one that doesn't
> generate lots of RFI.


I have an inexpensive CyberPower 825 AVR UPS, The UPS does the job of
keeping my computer and time-nuts gear running, but it causes an annoying
amount of RFI in the AM broadcast band. The noise is radiated from the
circuit that feeds the UPS. I found that plugging the UPS into a Belkin
outlet strip, which presumably includes some line filtering,reduced the
interference significantly.


-- 

--Jim Harman
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Re: [time-nuts] UPS for my time rack

[Bob Camp]

Hi

In the US, you dig those systems up either via R/V outfits or from the guys who 
set up big boats 
(think water borne RVs rather than super tankers). The other source are the off 
grid solar guys. 
A lot depends on just how fancy a system you are after. With reasonable effort 
you can pick up systems
up into the several 100 KW range. 

Bob

> On Oct 11, 2015, at 4:11 PM, Mark Spencer <m...@alignedsolutions.com> wrote:
> 
> I've also seen inverter systems that are designed for stand by power use in 
> service at commercial sites in third world countries.  Within reason they 
> basically let you run what ever reasonable arrangement of rechargeable lead 
> acid based batteries you want that will supply the required voltage and 
> current.  They handle the conversion of dc to ac and the switch over from 
> commercial to inverter power.   They usually also feature a basic battery 
> charger with settings to charge various types of batteries (ie, gel or 
> conventional lead acid.)
> 
> Typically I've seen them used with a number of automotive style batteries.
> 
> The users would need to sort out the necessary cables, fuses, batteries, deal 
> with safety considerations etc.
> 
> I've never seen these devices in Canada or the U.S.  Sort of a value 
> engineered UPS system for price conscious markets.  Might be a nice starting 
> point for those who want to role their own system and can deal with the 
> safety aspects of this.   I'm not sure what the transfer time from utility to 
> inverter power would be.
> 
> In the U.S. and Canada the typical practice seems to be to use packaged UPS 
> systems that include their own batteries.  
> 
> 
> Sent from my iPhone
> 
>> On Oct 11, 2015, at 10:36 AM, Bob Benward <rbenw...@verizon.net> wrote:
>> 
>> Dave, 
>> You could use a 120V relay and switch the high capacity battery from its own
>> charger to the battery pack in the UPS.  When power comes back, the relay
>> automatically switches the battery out and back to its own charger.
>> 
>> Bob
>> 
>>>>> -Original Message-
>>>>> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Dr.
>>>>> David Kirkby (Kirkby Microwave Ltd)
>>>>> Sent: Saturday, October 10, 2015 6:07 PM
>>>>> To: Discussion of precise time and frequency measurement
>>>>> Subject: Re: [time-nuts] UPS for my time rack
>>>>> 
>>>>>> On 10 October 2015 at 14:20, Chris Waldrup <kd4...@gmail.com> wrote:
>>>>>> 
>>>>>> Hi,
>>>>>> 
>>>>>> 
>>>>>> I have decided I'd like to get a UPS to put on the rack containing my
>>>>>> Thunderbolt, the laptop that runs Lady Heather, and frequency counter.
>>>>> 
>>>>> There's one issue with them that I don't see anyone mention.
>>>>> 
>>>>> I was thinking of doing the same a while back, and intended getting a
>> UPS
>>>>> and adding a large external battery pack, so if the mains failed late at
>> night, I
>>>>> could run the GPS receiver and a few other things overnight, and
>> consider
>>>>> starting the generator in the morning.  I contacted a dealer on eBay,
>> who
>>>>> specilaises in UPSs. He told me that the smaller units with built in
>> batteries
>>>>> will die if you put large external batteries on them.
>>>>> Essentially the charging circuits are not designed to run as long as
>> needed to
>>>>> charge big batteries. Even on ones designed for external batteries,
>> there's a
>>>>> recommended limit on the size of them. So if you think you might want to
>>>>> increase runtime by adding some batteries, buy one designed for that
>> service.
>>>>> 
>>>>> I've had two here which were HP/Compaq 5 kW units. These were different
>>>>> to the normal, in that the batteries added up to over 300 V, so could
>> produce
>>>>> 240 VAC with no need to step it up. Both these blew up on me, for
>> reasons I
>>>>> never worked out. The load was never anywhere near 5 kW.
>>>>> 
>>>>> Lots of people mention sine wave. Of course, if you keen enough, you
>> could
>>>>> make a class A amplifier and sine wave oscillator. The problem is that
>> the
>>>>> pure sine wave inverters tend to be very inefficient.
>>>>> 
>>>>> As with most things, there are a lot of things to balance - runtime,
>> cost,

Re: [time-nuts] UPS for my time rack

[Poul-Henning Kamp]

In message <183218108.6a07c91c@Nodemailer>, "Chris Waldrup" writes:


>Has anyone had bad experience noise wise with the APC brand units
>like are available on Amazon and at Staples? I'd like to get one
>that doesn't generate lots of RFI. Thank you. 

Then don't.

Instead get 12 or 24 Volt sealed lead-acid batteries and a good
float-charger, and run your stuff from that.

You avoid a lot of conversion losses, and you get to decide what
quality batteries you want (As opposed to "the cheapest we can get
away with") and you get to decide how long hold-up time you want.

The important tricks are:

  1. ATO Fuse *RIGHT NEXT TO THE BATTERY*.  Not a meter away, but
 quite literally bolted right onto the terminal.

  2. Don't buy a shit charger, it will cost you battery life.

  3. Suitably sized fuse/polyfuses on all loads.

  4. Either put 0.010 Ohm current shunts in all over the place
 or buy a 1mA resolution clamp meter and prepare the wiring
 for measurement.

And that's it really...

I run all the always-on stuff in my lab from two 12V/105Ah telco-grade
sealed lead-acid batteries, and I'll never look back.

Presenty the load is 6.7A @ 24V, and that powers my ADSL lines,
firewalls (soekris), home server (ITX with mini-box.com PSU),
emergency lights (LED strips), GPS, GPSDO, HP5065 etc. etc.


-- 
Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since RFC 956
FreeBSD committer   | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
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Re: [time-nuts] UPS for my time rack

[Mark Spencer]

Hi over the last 10 years or so I've purchased several consumer / small office 
grade UPS's from sources such as Staples and Costco.   I've never noted any RFI 
from them but I live in a (rf) noisy urban neighbourhood so any noise they put 
out is probably hard to notice.

Other than occasionally turning some of them off and on and seeing if I can see 
or hear any (additional) RFI on frequencies of interest I've never really 
looked for RFI from them.   

Several years ago I started putting ferrite chokes on the feed lines for my 
antennas and have almost completely  switched to double shielded cables for my 
amateur radio and time nuts activities.

Hope these comments are of some interest.

Mark S
VE7AFZ


Sent from my iPhone

> On Oct 10, 2015, at 6:20 AM, Chris Waldrup  wrote:
> 
> Hi,
> 
> 
> I have decided I'd like to get a UPS to put on the rack containing my 
> Thunderbolt, the laptop that runs Lady Heather, and frequency counter. 
> Has anyone had bad experience noise wise with the APC brand units like are 
> available on Amazon and at Staples? I'd like to get one that doesn't generate 
> lots of RFI. Thank you. 
> 
> 
> Chris
> KD4PBJ
> 
> —
> Sent from Mailbox
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Re: [time-nuts] UPS for my time rack

[Bob Camp]

Hi

All of the UPS vendors these days make a wide range of products. They range 
from 
low cost to mighty expensive. They also range a bit in terms of performance. 
Finding out
exactly what this or that model *does* do can be a major pain. The marketing 
guys apparently
don’t want you to figure out that the low cost gizmo does not have all the 
performance 
of the one that costs 5 times as much. 

First thing to avoid - the pure square wave output versions. These may or may 
not
generate RFI in this or that UHF band. They will take out big chunks of HF and 
mess up 10 MHz
distribution. I suspect that the filters on some are better than the filters on 
others. The bigger issue
is that they do not play nice with modern power factor corrected power 
supplies. These supplies 
seem to expect a sine wave and a (possibly ringing) square wave may get them 
confused.

Next thing to avoid - The stepped square wave / modified square wave versions. 
Theses aren’t 
quite as bad as the centuries old square wave units. It’s more likely you will 
find these than a 
pure square. They still have the same issues on RFI. They may or may not 
antagonize a PFC 
supply to the same extent. 

The target is a “pure sine wave” output. That keeps a PFC supply happy. As with 
any verbal spec, 
“pure” likely has a few qualifiers on it. It’s not guaranteed to take out the 
RFI. It at least will reduce 
the spikes on your 1 pps lines. If you look at the output on a ’scope the 
waveform at least *looks* like
a sine wave. 

All of these gizmos run a switcher in the “few hundred KHz” range to generate 
the output. They run 
a similar switcher to charge the battery. None of them are compatible with an 
indoor antenna in the same
room trying to listen to MF. None of the ones I have tried are nasty enough to 
bother GPS, either indoor or
outdoor. Put another way, I’ve had more trouble from LED lights than from sine 
wave UPS’s. 

Cyber Power (via Amazon) seems to make some pretty good stuff at a price point 
a bit below APC. As
with everybody else, it’s a pain to figure out what’s what. Are you after a 
“big” rack mount unit (as in $500
and up) or something smaller?

Bob 


> On Oct 10, 2015, at 9:20 AM, Chris Waldrup  wrote:
> 
> Hi,
> 
> 
> I have decided I'd like to get a UPS to put on the rack containing my 
> Thunderbolt, the laptop that runs Lady Heather, and frequency counter. 
> Has anyone had bad experience noise wise with the APC brand units like are 
> available on Amazon and at Staples? I'd like to get one that doesn't generate 
> lots of RFI. Thank you. 
> 
> 
> Chris
> KD4PBJ
> 
> —
> Sent from Mailbox
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Re: [time-nuts] UPS for my time rack

[Bob Camp]

Hi

If you do *any* VLF, then anything with an inverter in it is going to be a 
potential disaster. It
will purely be a case of the inverter being at a frequency that bugs you right 
now. None of
the ones I have seen are tightly controlled in frequency. What they do today 
probably will not
be what they do tomorrow. 

Indoors vs outdoors does not matter as much when a tenth wavelength is into the 
next county. 
The inverter in one of these gizmos is effectively a 1KW transmitter at (say) 
60 KHz. Yes filters 
can help. They will rarely do the trick when you are trying to listen to 
something at 60, 120, 180,
240 or 360 KHz. Since that’s 60 KHz +/- lots, those “wiped out” segments are 
also pretty wide. 

Bob

> On Oct 10, 2015, at 11:59 AM, Chris Waldrup  wrote:
> 
> Hi,
> 
> Thanks for the comments this morning. 
> 
> I'm not looking for something huge, maybe in the under $200 range. Just 
> enough for the Thunderbolt, laptop, and Agilent 53131A counter. I'd like a 
> little headroom though, as I may add another Thunderbolt or a rubidium 
> standard someday. 
> 
> I do like the 12 V battery idea. I run my ham gear off a 12 V gel cell (I'm 
> mainly QRP so a 32 Ah cell works for me) and I have a 12 V distribution 
> system with Anderson Power Poles on my operating bench. 
> 
> I do a lot of VLF and LF listening but my antennas are outside.  Nothing at 
> this time above 2 meters. 
> 
>  I live in a very quiet rural area on top of a mountain in Tennessee. So not 
> much man made noise at all and I wanted to keep it quiet emission wise. 
> 
> Thanks for all your help.
> 
> 
> 
> 
> Chris
> 
> KD4PBJ
> 
> 
> 
> —
> Sent from Mailbox
> 
> On Sat, Oct 10, 2015 at 10:05 AM, Mark Spencer 
> wrote:
> 
>> Hi over the last 10 years or so I've purchased several consumer / small 
>> office grade UPS's from sources such as Staples and Costco.   I've never 
>> noted any RFI from them but I live in a (rf) noisy urban neighbourhood so 
>> any noise they put out is probably hard to notice.
>> Other than occasionally turning some of them off and on and seeing if I can 
>> see or hear any (additional) RFI on frequencies of interest I've never 
>> really looked for RFI from them.   
>> Several years ago I started putting ferrite chokes on the feed lines for my 
>> antennas and have almost completely  switched to double shielded cables for 
>> my amateur radio and time nuts activities.
>> Hope these comments are of some interest.
>> Mark S
>> VE7AFZ
>> Sent from my iPhone
>>> On Oct 10, 2015, at 6:20 AM, Chris Waldrup  wrote:
>>> 
>>> Hi,
>>> 
>>> 
>>> I have decided I'd like to get a UPS to put on the rack containing my 
>>> Thunderbolt, the laptop that runs Lady Heather, and frequency counter. 
>>> Has anyone had bad experience noise wise with the APC brand units like are 
>>> available on Amazon and at Staples? I'd like to get one that doesn't 
>>> generate lots of RFI. Thank you. 
>>> 
>>> 
>>> Chris
>>> KD4PBJ
>>> 
>>> —
>>> Sent from Mailbox
>>> ___
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>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>>> 
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Re: [time-nuts] UPS for my time rack

[Alex Pummer]

for a very similar application I am using a solar panel to charge the 
battery, but I have a vented NiFe battery, which is not sensitive of 
over charging or deep discharging, and has almost unlimited life time -- 
I have seen some in forklifts which were 60 years old and working...

73
KJ6UHN
Alex



On 10/10/2015 7:14 AM, Poul-Henning Kamp wrote:


In message <183218108.6a07c91c@Nodemailer>, "Chris Waldrup" writes:



Has anyone had bad experience noise wise with the APC brand units
like are available on Amazon and at Staples? I'd like to get one
that doesn't generate lots of RFI. Thank you.

Then don't.

Instead get 12 or 24 Volt sealed lead-acid batteries and a good
float-charger, and run your stuff from that.

You avoid a lot of conversion losses, and you get to decide what
quality batteries you want (As opposed to "the cheapest we can get
away with") and you get to decide how long hold-up time you want.

The important tricks are:

   1. ATO Fuse *RIGHT NEXT TO THE BATTERY*.  Not a meter away, but
  quite literally bolted right onto the terminal.

   2. Don't buy a shit charger, it will cost you battery life.

   3. Suitably sized fuse/polyfuses on all loads.

   4. Either put 0.010 Ohm current shunts in all over the place
  or buy a 1mA resolution clamp meter and prepare the wiring
  for measurement.

And that's it really...

I run all the always-on stuff in my lab from two 12V/105Ah telco-grade
sealed lead-acid batteries, and I'll never look back.

Presenty the load is 6.7A @ 24V, and that powers my ADSL lines,
firewalls (soekris), home server (ITX with mini-box.com PSU),
emergency lights (LED strips), GPS, GPSDO, HP5065 etc. etc.




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[time-nuts] UPS for my time rack

[Chris Waldrup]

Hi,


I have decided I'd like to get a UPS to put on the rack containing my 
Thunderbolt, the laptop that runs Lady Heather, and frequency counter. 
Has anyone had bad experience noise wise with the APC brand units like are 
available on Amazon and at Staples? I'd like to get one that doesn't generate 
lots of RFI. Thank you. 


Chris
KD4PBJ

—
Sent from Mailbox
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Re: [time-nuts] UPS for my time rack

[Chris Waldrup]

Hi,

Thanks for the comments this morning. 

I'm not looking for something huge, maybe in the under $200 range. Just enough 
for the Thunderbolt, laptop, and Agilent 53131A counter. I'd like a little 
headroom though, as I may add another Thunderbolt or a rubidium standard 
someday. 

I do like the 12 V battery idea. I run my ham gear off a 12 V gel cell (I'm 
mainly QRP so a 32 Ah cell works for me) and I have a 12 V distribution system 
with Anderson Power Poles on my operating bench. 

I do a lot of VLF and LF listening but my antennas are outside.  Nothing at 
this time above 2 meters. 

 I live in a very quiet rural area on top of a mountain in Tennessee. So not 
much man made noise at all and I wanted to keep it quiet emission wise. 

Thanks for all your help.




Chris

KD4PBJ



—
Sent from Mailbox

On Sat, Oct 10, 2015 at 10:05 AM, Mark Spencer 
wrote:

> Hi over the last 10 years or so I've purchased several consumer / small 
> office grade UPS's from sources such as Staples and Costco.   I've never 
> noted any RFI from them but I live in a (rf) noisy urban neighbourhood so any 
> noise they put out is probably hard to notice.
> Other than occasionally turning some of them off and on and seeing if I can 
> see or hear any (additional) RFI on frequencies of interest I've never really 
> looked for RFI from them.   
> Several years ago I started putting ferrite chokes on the feed lines for my 
> antennas and have almost completely  switched to double shielded cables for 
> my amateur radio and time nuts activities.
> Hope these comments are of some interest.
> Mark S
> VE7AFZ
> Sent from my iPhone
>> On Oct 10, 2015, at 6:20 AM, Chris Waldrup  wrote:
>> 
>> Hi,
>> 
>> 
>> I have decided I'd like to get a UPS to put on the rack containing my 
>> Thunderbolt, the laptop that runs Lady Heather, and frequency counter. 
>> Has anyone had bad experience noise wise with the APC brand units like are 
>> available on Amazon and at Staples? I'd like to get one that doesn't 
>> generate lots of RFI. Thank you. 
>> 
>> 
>> Chris
>> KD4PBJ
>> 
>> —
>> Sent from Mailbox
>> ___
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>> and follow the instructions there.
>> 
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Re: [time-nuts] UPS for my time rack

[Mark Spencer]

A quick comment about "pure sine" devices.

At times I operate a portable VHF and up radio system from rf quiet out of the 
way places.   I run almost all the equipment from lead acid storage batteries.  
 I have small 30 dollar inverter I use to occasionally  power some equipment 
that needs 120 volts AC.   It puts out very little RFI.   I figured I'd upgrade 
to a much more expensive pure sine Inverter (I also wanted to run some linear 
power supplies from the inverter as well to get better voltage regulation for 
some of the equipment.)  It was a disaster from an RFI perspective.


Your mileage may vary.

Mark S
VE7AFZ

Sent from my iPad

On 2015-10-10, at 7:51 AM, Bob Camp  wrote:

> Hi
> 
> All of the UPS vendors these days make a wide range of products. They range 
> from 
> low cost to mighty expensive. They also range a bit in terms of performance. 
> Finding out
> exactly what this or that model *does* do can be a major pain. The marketing 
> guys apparently
> don’t want you to figure out that the low cost gizmo does not have all the 
> performance 
> of the one that costs 5 times as much. 
> 
> First thing to avoid - the pure square wave output versions. These may or may 
> not
> generate RFI in this or that UHF band. They will take out big chunks of HF 
> and mess up 10 MHz
> distribution. I suspect that the filters on some are better than the filters 
> on others. The bigger issue
> is that they do not play nice with modern power factor corrected power 
> supplies. These supplies 
> seem to expect a sine wave and a (possibly ringing) square wave may get them 
> confused.
> 
> Next thing to avoid - The stepped square wave / modified square wave 
> versions. Theses aren’t 
> quite as bad as the centuries old square wave units. It’s more likely you 
> will find these than a 
> pure square. They still have the same issues on RFI. They may or may not 
> antagonize a PFC 
> supply to the same extent. 
> 
> The target is a “pure sine wave” output. That keeps a PFC supply happy. As 
> with any verbal spec, 
> “pure” likely has a few qualifiers on it. It’s not guaranteed to take out the 
> RFI. It at least will reduce 
> the spikes on your 1 pps lines. If you look at the output on a ’scope the 
> waveform at least *looks* like
> a sine wave. 
> 
> All of these gizmos run a switcher in the “few hundred KHz” range to generate 
> the output. They run 
> a similar switcher to charge the battery. None of them are compatible with an 
> indoor antenna in the same
> room trying to listen to MF. None of the ones I have tried are nasty enough 
> to bother GPS, either indoor or
> outdoor. Put another way, I’ve had more trouble from LED lights than from 
> sine wave UPS’s. 
> 
> Cyber Power (via Amazon) seems to make some pretty good stuff at a price 
> point a bit below APC. As
> with everybody else, it’s a pain to figure out what’s what. Are you after a 
> “big” rack mount unit (as in $500
> and up) or something smaller?
> 
> Bob 
> 
> 
>> On Oct 10, 2015, at 9:20 AM, Chris Waldrup  wrote:
>> 
>> Hi,
>> 
>> 
>> I have decided I'd like to get a UPS to put on the rack containing my 
>> Thunderbolt, the laptop that runs Lady Heather, and frequency counter. 
>> Has anyone had bad experience noise wise with the APC brand units like are 
>> available on Amazon and at Staples? I'd like to get one that doesn't 
>> generate lots of RFI. Thank you. 
>> 
>> 
>> Chris
>> KD4PBJ
>> 
>> —
>> Sent from Mailbox
>> ___
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>> and follow the instructions there.
> 
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Re: [time-nuts] UPS for my time rack

[Jim Sanford]

I have 3 APC SmartUPS2200NET UPSs.  I have detected no interference to 
my HF ham station from these.  One antenna is several hundred feet away; 
another passes less than 10 feet away.  I have listened to these with an 
IC-R10, and not found much noise.


I get much more from noise radiated by ethernet cables, unless I have 
choked them (which is effective).


I bought a sun-power (I think) 1KW sine wave inverter for ham radio 
field day use, to run antenna rotors, etc.  While not a disaster, it 
will have to be in a shielded box and all cables in and out choked, to 
not interfere with HF communications.  Based on rough measurements, I 
don't think much of a problem at 1 GHz.


Good luck!
Jim
wb4...@amsat.org


On 10/10/2015 2:32 PM, Esa Heikkinen wrote:

Chris Waldrup kirjoitti:


I have decided I'd like to get a UPS to put on the rack containing my
Thunderbolt, the laptop that runs Lady Heather, and frequency
counter. Has anyone had bad experience noise wise with the APC brand
units like are available on Amazon and at Staples? I'd like to get
one that doesn't generate lots of RFI. Thank you.


Get a line-interactive model which has inverter with classic iron 
transformer. Line-interactive means that the inverter is not 
continuously on when the mains voltage is OK, but the mais voltage is 
routed thru multitap transformer which gives some filtering and 
enables to fix under/overvoltage errors without turning on the 
inverter. When there's blackout and inverter is really started the 
transformer will act as a filter which reduces the HF interference 
caused by sine wave inverter.


You can recognize this kind of ups from treir weight. For example 2 
kVA model should weight more than 25 kg without batteries and more 
than 50 kg with batteries. You could look for example old APC 
SmartUPSes or APC Matrix UPS, which has separate inverter unit, 
transformer unit and battery units. Old SmartUPS'es may require float 
voltage modification because their charging voltage tends to increase 
when aging. Without fix it will kill the batteries too soon.


Worst case to buy is double conversion on-line model without any kind 
of transformer. These are cheap but the inverter is on all the time 
and it's output is not filtered. I have measured the output of these 
kind of UPSes with spectrum analyzer and they are really horrible 
interference sources. Not recommended if there's any kind of sensitive 
electronics.


Regards,




---
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Re: [time-nuts] UPS for my time rack

[Esa Heikkinen]

Chris Waldrup kirjoitti:


I have decided I'd like to get a UPS to put on the rack containing my
Thunderbolt, the laptop that runs Lady Heather, and frequency
counter. Has anyone had bad experience noise wise with the APC brand
units like are available on Amazon and at Staples? I'd like to get
one that doesn't generate lots of RFI. Thank you.


Get a line-interactive model which has inverter with classic iron 
transformer. Line-interactive means that the inverter is not 
continuously on when the mains voltage is OK, but the mais voltage is 
routed thru multitap transformer which gives some filtering and enables 
to fix under/overvoltage errors without turning on the inverter. When 
there's blackout and inverter is really started the transformer will act 
as a filter which reduces the HF interference caused by sine wave inverter.


You can recognize this kind of ups from treir weight. For example 2 kVA 
model should weight more than 25 kg without batteries and more than 50 
kg with batteries. You could look for example old APC SmartUPSes or APC 
Matrix UPS, which has separate inverter unit, transformer unit and 
battery units. Old SmartUPS'es may require float voltage modification 
because their charging voltage tends to increase when aging. Without fix 
it will kill the batteries too soon.


Worst case to buy is double conversion on-line model without any kind of 
transformer. These are cheap but the inverter is on all the time and 
it's output is not filtered. I have measured the output of these kind of 
UPSes with spectrum analyzer and they are really horrible interference 
sources. Not recommended if there's any kind of sensitive electronics.


Regards,

--
73s!
Esa
OH4KJU
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Re: [time-nuts] UPS for my time rack

[Mark Spencer]

Just to add to this.  I've also been told that other pure sine inverters have 
worked well for others in similar applications. 

Not sure if mine was unusually bad or the frequencies it operated on happened 
to be related to the frequencies I was using.

Your success may vary.   

Best regards
Mark S

Sent from my iPhone

> On Oct 10, 2015, at 8:26 AM, Mark Spencer  wrote:
> 
> A quick comment about "pure sine" devices.
> 
> At times I operate a portable VHF and up radio system from rf quiet out of 
> the way places.   I run almost all the equipment from lead acid storage 
> batteries.   I have small 30 dollar inverter I use to occasionally  power 
> some equipment that needs 120 volts AC.   It puts out very little RFI.   I 
> figured I'd upgrade to a much more expensive pure sine Inverter (I also 
> wanted to run some linear power supplies from the inverter as well to get 
> better voltage regulation for some of the equipment.)  It was a disaster from 
> an RFI perspective.
> 
> 
> Your mileage may vary.
> 
> Mark S
> VE7AFZ
> 
> Sent from my iPad
> 
>> On 2015-10-10, at 7:51 AM, Bob Camp  wrote:
>> 
>> Hi
>> 
>> All of the UPS vendors these days make a wide range of products. They range 
>> from 
>> low cost to mighty expensive. They also range a bit in terms of performance. 
>> Finding out
>> exactly what this or that model *does* do can be a major pain. The marketing 
>> guys apparently
>> don’t want you to figure out that the low cost gizmo does not have all the 
>> performance 
>> of the one that costs 5 times as much. 
>> 
>> First thing to avoid - the pure square wave output versions. These may or 
>> may not
>> generate RFI in this or that UHF band. They will take out big chunks of HF 
>> and mess up 10 MHz
>> distribution. I suspect that the filters on some are better than the filters 
>> on others. The bigger issue
>> is that they do not play nice with modern power factor corrected power 
>> supplies. These supplies 
>> seem to expect a sine wave and a (possibly ringing) square wave may get them 
>> confused.
>> 
>> Next thing to avoid - The stepped square wave / modified square wave 
>> versions. Theses aren’t 
>> quite as bad as the centuries old square wave units. It’s more likely you 
>> will find these than a 
>> pure square. They still have the same issues on RFI. They may or may not 
>> antagonize a PFC 
>> supply to the same extent. 
>> 
>> The target is a “pure sine wave” output. That keeps a PFC supply happy. As 
>> with any verbal spec, 
>> “pure” likely has a few qualifiers on it. It’s not guaranteed to take out 
>> the RFI. It at least will reduce 
>> the spikes on your 1 pps lines. If you look at the output on a ’scope the 
>> waveform at least *looks* like
>> a sine wave. 
>> 
>> All of these gizmos run a switcher in the “few hundred KHz” range to 
>> generate the output. They run 
>> a similar switcher to charge the battery. None of them are compatible with 
>> an indoor antenna in the same
>> room trying to listen to MF. None of the ones I have tried are nasty enough 
>> to bother GPS, either indoor or
>> outdoor. Put another way, I’ve had more trouble from LED lights than from 
>> sine wave UPS’s. 
>> 
>> Cyber Power (via Amazon) seems to make some pretty good stuff at a price 
>> point a bit below APC. As
>> with everybody else, it’s a pain to figure out what’s what. Are you after a 
>> “big” rack mount unit (as in $500
>> and up) or something smaller?
>> 
>> Bob 
>> 
>> 
>>> On Oct 10, 2015, at 9:20 AM, Chris Waldrup  wrote:
>>> 
>>> Hi,
>>> 
>>> 
>>> I have decided I'd like to get a UPS to put on the rack containing my 
>>> Thunderbolt, the laptop that runs Lady Heather, and frequency counter. 
>>> Has anyone had bad experience noise wise with the APC brand units like are 
>>> available on Amazon and at Staples? I'd like to get one that doesn't 
>>> generate lots of RFI. Thank you. 
>>> 
>>> 
>>> Chris
>>> KD4PBJ
>>> 
>>> —
>>> Sent from Mailbox
>>> ___
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>>> To unsubscribe, go to 
>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>> 
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>> and follow the instructions there.
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Re: [time-nuts] UPS for my time rack

[Bill Hawkins]

>From experience, here's a story about a very quiet (RF-wise) pretty good
sine wave UPS device.

I acquired a Liebert 2KVA UPS for data centers in 1999 when our division
was declared redundant. The cost when new would be prohibitive, but this
one was junked when it stopped working. I got it, found a bad
electrolytic cap (from the stains) and replaced it. Worked well. Never
did get a manual, had to trace the switching stuff.

This was from the days when data centers could afford the best in
immortal power. The line feeds a regulated DC supply that runs the sine
wave inverter and maintains battery charge. The inverter runs in sync
with the line, but a relay connects the line to the load while the
inverter idles. When the line fails, batteries supply the inverter and
the relay switches it to the load. Then a cooling fan starts up.

This machine required eight 12 volt batteries for 96 VDC nominal, higher
on float charge. I bought 15 amp-hour batteries and wired them to a
connector on the back intended for external batteries. Lethal voltage,
of course. Requires proper protection.

Also had a line voltage relay and toggle switch that would bypass the
UPS and connect the time rack directly to the line. This allowed the UPS
to be replaced when its warranty ran out. Batteries lasted six years,
did not invest another $500 in them.

Good luck.

Bill Hawkins


-Original Message-
From: Chris Waldrup
Sent: Saturday, October 10, 2015 8:20 AM
To: TIme Nuts
Subject: [time-nuts] UPS for my time rack

Hi,

I have decided I'd like to get a UPS to put on the rack containing my
Thunderbolt, the laptop that runs Lady Heather, and frequency counter.
Has anyone had bad experience noise wise with the APC brand units like
are available on Amazon and at Staples? I'd like to get one that doesn't
generate lots of RFI. Thank you. 

Chris
KD4PBJ


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Re: [time-nuts] UPS for my time rack

[Dr. David Kirkby (Kirkby Microwave Ltd)]

On 10 October 2015 at 14:20, Chris Waldrup  wrote:

> Hi,
>
>
> I have decided I'd like to get a UPS to put on the rack containing my
> Thunderbolt, the laptop that runs Lady Heather, and frequency counter.
>

There's one issue with them that I don't see anyone mention.

I was thinking of doing the same a while back, and intended getting a UPS
and adding a large external battery pack, so if the mains failed late at
night, I could run the GPS receiver and a few other things overnight, and
consider starting the generator in the morning.  I contacted a dealer on
eBay, who specilaises in UPSs. He told me that the smaller units with built
in batteries will die if you put large external batteries on them.
Essentially the charging circuits are not designed to run as long as needed
to charge big batteries. Even on ones designed for external batteries,
there's a recommended limit on the size of them. So if you think you might
want to increase runtime by adding some batteries, buy one designed for
that service.

I've had two here which were HP/Compaq 5 kW units. These were different to
the normal, in that the batteries added up to over 300 V, so could produce
240 VAC with no need to step it up. Both these blew up on me, for reasons I
never worked out. The load was never anywhere near 5 kW.

Lots of people mention sine wave. Of course, if you keen enough, you could
make a class A amplifier and sine wave oscillator. The problem is that the
pure sine wave inverters tend to be very inefficient.

As with most things, there are a lot of things to balance - runtime, cost,
quality of output, audio noise, RFI  etc etc.

Dave
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