Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
Hal Murray writes:
> What's the lifetime of a modern lead-acid battery that a telco would use?
That's a slightly embarrasing story actually...
The "Round Telco" battery which Bell Labs designed, is virtually
impossible to kill if you have read the manual.
Needless to say, this made them unpopular with battery manufacturers.
Modern telco management also does not hold the "40 years lifetime
or bust" from last century.
So these days Telcos use "prismatic" VRLA batteries, and they swap them
out every 5-10 years, depending on just about everything.
In the USA, hold-up regulations were tightened after hurricane
Katrina, and since much of a telcos network these days are in the
mobile base-stations, focus has shifted to how you economically
provide backup power in a cabinet in the landscape.
That is a very lead-acid hostile enviroment, so telcos experiment
with all sorts of stuff, fuel-cells (methane & hydrogen), li-batteries,
NiFe ("edison") batteries etc. etc.
BATTCON papers used to be a god place to read along, but as I mentioned
that seems to have lost its luster.
--
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.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
> Real Telco gear runs from -48VDC fed from, literally, tons of lead-acid > batteries. I remember from ages ago some comment about telcos using iron rather than lead. Google finds Edison batteries, nickel-iron. Long life being their primary feature. https://en.wikipedia.org/wiki/Nickel%E2%80%93iron_battery 12V, 100AH, $1,093 https://ironedison.com/nickel-iron-ni-fe-battery That's their smallest size. I think they require maintenance -- fill them up occasionally. What's the lifetime of a modern lead-acid battery that a telco would use? -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
Yes running being able to run at least some of my OCXO's from a DC battery system is my desired state of affairs for my home time lab. It is nice to have two devices that have been running for a decade. Anyways thanks all for the comments about various ways to power my BVA and the trip down memory lane re large UPS systems, Telecom battery plants etc. It will be nice to have the BVA powered from the a DC battery system. I will be curious to see how the BVA performs after being powered up for at least a year. Currently after running for a month or so it seems to often outperform the other OCXO's that have been running for a decade or so. Between occasional power outages that exceed typical UPS run times and the need to change batteries on occasion in the consumer grade UPS systems I use in my home time lab, getting multi year un interrupted run times without using a DC battery system to power devices during AC power outages seems unlikely for me. Mark Spencer m...@alignedsolutions.com 604 762 4099 > On Sep 27, 2020, at 4:06 AM, Magnus Danielson wrote: > > Hi, > >> On 2020-09-27 09:02, Poul-Henning Kamp wrote: >> >> Bill Notfaded writes: >> >>> Are you saying if the load is small it'll still run out pretty quickly? >> Yes. >> >> The constant loss of the inverter-stage will be nothing compared >> to the full design load, but will totally swamp your light load. >> >> This is why UPS vendors only publish hold-up times for full load. > Which is why it is a good idea to run the load directly off the > batteries. In telecom, that is -48 VDC (check out the ETSI EN 300 132-2 > spec) but there is also one for modern switch-mode supplies for more > IT-infrastructure which is feeding the 230 VAC side the DC it achieves > after rectifier (ETSI EN 300 132-3 spec), but that has not taken off as > far as I know. Both avoids the inverter part. Running straight of the > batteries for 24 VDC matches many of our devices. For instance, all the > atomic clocks and many OCXOs I have essentially run off 24 VDC, so that > will be my focus. > > The voltage range for the -48 VDC is really -40 VDC to -60,5 VDC to > match the out of charge to charging voltages of normal lead-acid batteries. > > Sure, the 24 V or 48 V may not fit the needs of applications, but you > can usually find DC/DC converters that can be decent enough loss-wise as > they do switched mode drop-regulation. Choosing wisely amongst those, > you can get better losses than a large supply which runs in a > non-optimal mode. > > Cheers, > Magnus > > > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
Hi, On 2020-09-27 09:02, Poul-Henning Kamp wrote: > > Bill Notfaded writes: > >> Are you saying if the load is small it'll still run out pretty quickly? > Yes. > > The constant loss of the inverter-stage will be nothing compared > to the full design load, but will totally swamp your light load. > > This is why UPS vendors only publish hold-up times for full load. > Which is why it is a good idea to run the load directly off the batteries. In telecom, that is -48 VDC (check out the ETSI EN 300 132-2 spec) but there is also one for modern switch-mode supplies for more IT-infrastructure which is feeding the 230 VAC side the DC it achieves after rectifier (ETSI EN 300 132-3 spec), but that has not taken off as far as I know. Both avoids the inverter part. Running straight of the batteries for 24 VDC matches many of our devices. For instance, all the atomic clocks and many OCXOs I have essentially run off 24 VDC, so that will be my focus. The voltage range for the -48 VDC is really -40 VDC to -60,5 VDC to match the out of charge to charging voltages of normal lead-acid batteries. Sure, the 24 V or 48 V may not fit the needs of applications, but you can usually find DC/DC converters that can be decent enough loss-wise as they do switched mode drop-regulation. Choosing wisely amongst those, you can get better losses than a large supply which runs in a non-optimal mode. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
Bill Notfaded writes: > Are you saying if the load is small it'll still run out pretty quickly? Yes. The constant loss of the inverter-stage will be nothing compared to the full design load, but will totally swamp your light load. This is why UPS vendors only publish hold-up times for full load. -- 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. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
Where I work on a smaller isolated network we have an APC that takes up one full rack. Most of the rack is modular batteries that are 6 batteries in 19" x 4U high... A bunch of rows of these in one rack with a few units that are the control and monitoring system. That one rack can support 6 rows of racks of equipment 5 19" racks wide. That one APC rack can run all the computers, NAS, blade centers, etc. for about an hour. Some of the racks are 110AC some are 208AC depending on circuit it's on. It seems like I could get one of the bottom of the rack APC units (really heavy) that are I think 4U high. The batteries usually last longer depending on the load. Our big unit tells you right on the front how long in minutes it will last based on the current load. Are you saying if the load is small it'll still run out pretty quickly? I was thinking just plug a few things in: BVA power supply, HP 105B, some GPS/GNSSDO's and the HP5065A. I don't even think there's any reason to plug a Cesium into it. If a Cesium in storage mode is off for a while who cares right? I have a few older Efratom Rb too FRK-L and a couple M-100. Would those benefit from staying on? I have a few newer Rb but they would just run until Rubidium ran out right like SRS PRS-10 and L-Pro's? I've heard the older Rb can be ran all the time because they have much more Rubidium in them. Up to this point I usually run them for a couple days to stabilize them before using them. I'm not 100% sure if leaving them on all the time is of much benefit? I know Ed told me he leaves his 5065 on all the time so I'm planning the same thing right now also mines recently put back together and as it runs it's getting better and better right now. I really like these older Rb units with larger physics packages. Best Regards, Bill On Sat, Sep 26, 2020, 9:16 AM Mark Spencer wrote: > A few decades ago I worked with some quite large Telecom gear that ran > from 208 volt AC.The equipment had its own internal 48 volt supplies > and short term battery back up system (basically so the redundant CPU units > could gracefully shut down in the event of a power failure.) The > manufacturer also sold similar systems that ran from customer supplied 48 > volts but many enterprise customers who already had large UPS systems and > back up generators preferred the versions that ran from 208 volt AC. > > Some smaller office phone systems back in the early 1990's also featured > large external battery packs to get multi hour run times. The vendors > would typically send technicians out to peridoically check the battery > systems. The few that I was able to examine were typically made up from 2 > volt sealed lead acid cells. The used cells used to be some what > available to hobbyists as the tended to get replaced before they failed. > > Yes some large UPS systems don't work very well at supplying low levels of > power for long the periods. During a multi hour maintenance shut down at > work a few decades ago we had one device that we hoped to keep running > (essentially a small digital voice play back unit that played phone system > messages, ie. "The number you have reached is not in service.") It drew > well under 100 watts and was the only load at the time for a large UPS > system with multiple battery banks which stopped running after a few hours > and I had to re record the messages. None of us were very surprised. > > > Mark Spencer > m...@alignedsolutions.com > 604 762 4099 > > > On Sep 26, 2020, at 12:33 AM, Hal Murray > wrote: > > > > > >>> Can't I just use a high quality APC backup power system > >>> like we use to power racks of gear in our Telco and compute closets? > > > >> Very few UPS's are good at long-run applications, they are typically > built to > >> run a heavy load for minutes, not a tiny load for hours or even days on > end. > > > > That matches my expectations, but somebody might expect their telco gear > to > > stay up longer than the few minutes it takes to cleanly shut down a > computer. > > > > Is there a branch of UPS gear aimed at telco rather than computers? > That is > > good efficiency at low power and long time rather than high power for > short > > time. > > > > Does all telco gear that is expected to run off UPS take 48V? > > > > Is there a market in small 48V supplies with UPS option for the telco > market? > > You would have to build a 48V to 24V converter rather than the whole > thing. > > You can probably get a brick for that. > > > > > > > > -- > > These are my opinions. I hate spam. > > > > > > > > > > ___ > > time-nuts mailing list -- time-nuts@lists.febo.com > > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > > and follow the instructions there. > > > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to >
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
You want a substantial UPS go to Victron Energy and get a charger Inverter Multi Plus and add a battery I have done it. Bert KehrenIn a message dated 9/26/2020 12:16:16 PM Eastern Standard Time, m...@alignedsolutions.com writes: A few decades ago I worked with some quite large Telecom gear that ran from 208 volt AC. The equipment had its own internal 48 volt supplies and short term battery back up system (basically so the redundant CPU units could gracefully shut down in the event of a power failure.) The manufacturer also sold similar systems that ran from customer supplied 48 volts but many enterprise customers who already had large UPS systems and back up generators preferred the versions that ran from 208 volt AC. Some smaller office phone systems back in the early 1990's also featured large external battery packs to get multi hour run times. The vendors would typically send technicians out to peridoically check the battery systems. The few that I was able to examine were typically made up from 2 volt sealed lead acid cells. The used cells used to be some what available to hobbyists as the tended to get replaced before they failed. Yes some large UPS systems don't work very well at supplying low levels of power for long the periods. During a multi hour maintenance shut down at work a few decades ago we had one device that we hoped to keep running (essentially a small digital voice play back unit that played phone system messages, ie. "The number you have reached is not in service.") It drew well under 100 watts and was the only load at the time for a large UPS system with multiple battery banks which stopped running after a few hours and I had to re record the messages. None of us were very surprised. Mark Spencer m...@alignedsolutions.com 604 762 4099 > On Sep 26, 2020, at 12:33 AM, Hal Murray wrote: > > >>> Can't I just use a high quality APC backup power system >>> like we use to power racks of gear in our Telco and compute closets? > >> Very few UPS's are good at long-run applications, they are typically built to >> run a heavy load for minutes, not a tiny load for hours or even days on end. > > That matches my expectations, but somebody might expect their telco gear to > stay up longer than the few minutes it takes to cleanly shut down a computer. > > Is there a branch of UPS gear aimed at telco rather than computers? That is > good efficiency at low power and long time rather than high power for short > time. > > Does all telco gear that is expected to run off UPS take 48V? > > Is there a market in small 48V supplies with UPS option for the telco market? > > You would have to build a 48V to 24V converter rather than the whole thing. > You can probably get a brick for that. > > > > -- > These are my opinions. I hate spam. > > > > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
A few decades ago I worked with some quite large Telecom gear that ran from 208 volt AC.The equipment had its own internal 48 volt supplies and short term battery back up system (basically so the redundant CPU units could gracefully shut down in the event of a power failure.) The manufacturer also sold similar systems that ran from customer supplied 48 volts but many enterprise customers who already had large UPS systems and back up generators preferred the versions that ran from 208 volt AC. Some smaller office phone systems back in the early 1990's also featured large external battery packs to get multi hour run times. The vendors would typically send technicians out to peridoically check the battery systems. The few that I was able to examine were typically made up from 2 volt sealed lead acid cells. The used cells used to be some what available to hobbyists as the tended to get replaced before they failed. Yes some large UPS systems don't work very well at supplying low levels of power for long the periods. During a multi hour maintenance shut down at work a few decades ago we had one device that we hoped to keep running (essentially a small digital voice play back unit that played phone system messages, ie. "The number you have reached is not in service.") It drew well under 100 watts and was the only load at the time for a large UPS system with multiple battery banks which stopped running after a few hours and I had to re record the messages. None of us were very surprised. Mark Spencer m...@alignedsolutions.com 604 762 4099 > On Sep 26, 2020, at 12:33 AM, Hal Murray wrote: > > >>> Can't I just use a high quality APC backup power system >>> like we use to power racks of gear in our Telco and compute closets? > >> Very few UPS's are good at long-run applications, they are typically built to >> run a heavy load for minutes, not a tiny load for hours or even days on end. > > That matches my expectations, but somebody might expect their telco gear to > stay up longer than the few minutes it takes to cleanly shut down a computer. > > Is there a branch of UPS gear aimed at telco rather than computers? That is > good efficiency at low power and long time rather than high power for short > time. > > Does all telco gear that is expected to run off UPS take 48V? > > Is there a market in small 48V supplies with UPS option for the telco market? > > You would have to build a 48V to 24V converter rather than the whole thing. > You can probably get a brick for that. > > > > -- > These are my opinions. I hate spam. > > > > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
We have done exactly that not a week at a time because we have enough high
resolution and did it in 1 Volt steps down to 20 V no change. Current stays the
same. Bert Kehren In a message dated 9/25/2020 8:44:02 PM Eastern Standard
Time, p...@phk.freebsd.dk writes:
Mark Spencer writes:
> The bit I am struggling with re using a 24 volt battery system in this
> application is what happens when AC power is removed and the terminal
> voltage of the battery starts to fall.
Don't overengineer your supply (unless you absolutely want to :-)
It looks like the BVA is specified at 24V ±10%, which is 21.6-26.6V.
Nobody says 24 Volt is optimal in that interval, and I have
never been able to measure any difference on any OCXO, as long as
I stayed a few hundred millivolts above the lower limit.
I would run the BVA for a week at 24V, collecting PPS data against
a GPSDO or other suitable source.
Then I would run it for a week at 22V, collecting the same data.
If I could not tell the data from the two runs apart, I would design
a 22V supply.
The BVA is spec'ed at 3W steady state, at 22V that's ~150mA.
In long-run applications you get the name-plate capacity, so two
12V x 15 Ah VRLA blocks would keep your BVA happy for four days,
24Ah would last a week etc.
"Small" come from a lot of dubious manufacturers and which means
badly recycled and impure lead. For a golfcart that doesn't matter,
but it is a big disadvantage in long-run applications like this.
Saving 5 bucks on lead-acid batteries are usually a bad deal in the
long run, but on the other hand, dont say no if serious battery-people
offer you a couple of pre-owned large batteries cheap, just make
sure you can lift them.
Lead-Acid in long-duration applications should not be discharged much
below 1.85 V, and 12 cells times 1.85V = 22.2 Volt. Subtract a
diode drop, and now you know where the 24V±10% spec comes from in
the first place.
At 27.6 V float-charge, your linear regulator will have to deal with
(27.6-22)V * 150mA = .84W.
A LM317 would do a fine job, but you can reduce the voltage drop
and get longer runtime with a PNP based home-brew supply.
The float-charger should be able to power the BVA and also recharge
the battery in less than a day, so with 15Ah blocks, I would aim
for around 1-1.5 ampere.
Your batteries will live longer if they have individual chargers,
so something like a 2x12VAC 40-50W torroid trafo, two bridges, two
caps, two LM317's plus resistors and trimpots will do fine.
Poul-Henning
PS: practical hints:
Your local car-nut-emporium has fuseholders like these for cheap:
https://www.thansen.dk/bil/udstyr/eludstyr/kontakter-ledning-sikring/sikringer/sikringsholdere/sikringsholder-m.-kabel-fladsikring/n-497642816/pn-1939736599
Take two, crimp ring-lugs on one end of them, and bolt them directly
to the battery terminal: one for charger, one for load.
When using them next to batteries, the "contra" diode "backwards
across" the LM317 is mandatory.
"Real" UPS installers often have spare batteries which have been
kept on float-charge but otherwise unused, in case of a failure on
customer site. At end of contract, they dont need them any more.
Telephone people with 2V batteries are interesting too, but their
12V blocks are usually dead by the time the swap them out.
Power-grid people, in particular the nuclear plant people, can also
be a good source very, very good batteries with lots of life in
them still, but be very aware of the weight and the short-circuit
currents.
If you end up with pre-owned liquid electrolyte batteries ("OPzS")
make sure the hydrogen gas can vent safely out of the building.
--
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.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
Victron Energy has a nice application book on their web site the have super products, I used them on my 64 foot GOFAST. Besides products they also discuss battery technologies and applications. My hard copy is 15 years old. Here is the link in English https://www.victronenergy.com/upload/documents/Book-Energy-Unlimited-EN.pdf Bert Kehren In a message dated 9/25/2020 9:02:32 PM Eastern Standard Time, p...@phk.freebsd.dk writes: Bob kb8tq writes: > Two basic types of SLA / VRLA batteries out there: AGM and Gel. For the AGM > variety, you want a bit more to your charger. Yes, if you buy batteries for N * 100K $money, spending more money on your charger is a good investment. But if you have two batteries doing float-charge/long-run/tiny-load, in a benign environment in a corner of your lab, the internal variance between batteries in that same production lot, will overshadow any imaginable benefit a fancy charger could bring. >I haven't worked with Gel cells in a while so they may indeed be easier. They are for the same reasons they suffer cyclic use better. But for a float/long-run application, it makes absolutely no difference. -- 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. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
Hal Murray writes: > > Very few UPS's are good at long-run applications, they are typically built > > to > > run a heavy load for minutes, not a tiny load for hours or even days on > > end. > > That matches my expectations, but somebody might expect their telco gear to > stay up longer than the few minutes it takes to cleanly shut down a computer. Real Telco gear runs from -48VDC fed from, literally, tons of lead-acid batteries. Google "telco battery room" pictures if you dont belive me. Incidentally, the best batteries for this kind of application are literally called "circular telco batteries", and almost all of them are still in use, some of them pushing 50 years now: https://archive.org/details/bstj49-7-1253/page/n23/mode/2up > Does all telco gear that is expected to run off UPS take 48V? In the sense that telcos rarely buy anything but -48VDC kit: Yes. > Is there a market in small 48V supplies with UPS option for the telco market? > > You would have to build a 48V to 24V converter rather than the whole thing. > You can probably get a brick for that. All of 12, 24 and 48VDC are commonly used, and IMO most timing kit is 24VDC. 24VDC is also popular in industrial control settings, for instance: https://www.pulspower.com/products/supplementary-units/dc-ups-and-buffer-modules/ It's expensive and good, but these days almost all of it is switch-mode. -- 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. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
On Sat, Sep 26, 2020 at 7:36 AM Hal Murray wrote: > > >> Can't I just use a high quality APC backup power system > >> like we use to power racks of gear in our Telco and compute closets? > > > Very few UPS's are good at long-run applications, they are typically > built to > > run a heavy load for minutes, not a tiny load for hours or even days on > end. > > That matches my expectations, but somebody might expect their telco gear > to > stay up longer than the few minutes it takes to cleanly shut down a > computer. > > Is there a branch of UPS gear aimed at telco rather than computers? That > is > good efficiency at low power and long time rather than high power for > short > time. > > Does all telco gear that is expected to run off UPS take 48V? > 48VDC is common. Historically facilities that provide highly available AC usually do so via generator. The UPSes just need to last long enough for the generators to start. Keep in mind that during a long run HVAC needs to be supported too. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
>> Can't I just use a high quality APC backup power system >> like we use to power racks of gear in our Telco and compute closets? > Very few UPS's are good at long-run applications, they are typically built to > run a heavy load for minutes, not a tiny load for hours or even days on end. That matches my expectations, but somebody might expect their telco gear to stay up longer than the few minutes it takes to cleanly shut down a computer. Is there a branch of UPS gear aimed at telco rather than computers? That is good efficiency at low power and long time rather than high power for short time. Does all telco gear that is expected to run off UPS take 48V? Is there a market in small 48V supplies with UPS option for the telco market? You would have to build a 48V to 24V converter rather than the whole thing. You can probably get a brick for that. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
Bill Notfaded writes: > > Can't I just use a high quality APC backup power system like we use to > power racks of gear in our Telco and compute closets? Very few UPS's are good at long-run applications, they are typically built to run a heavy load for minutes, not a tiny load for hours or even days on end. That means low efficiency, 75% net efficiency is considered good, and it goes totally south the further you are from the name-plate load, because the constant overhead is large. Some UPSs dont even have a thermal design allowing 24*365 operation. If you want to power mains kit from batteries, it is usually better to get a "real" inverter which is built island-grid applications. But for powering small loads, OCXO's, GPSDO's, Rb's, fire alarms, emergency lighting etc, the overhead of going from battery voltage to mains voltage and back is just a unnecessary loss. -- 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. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
Good evening TGIF! You've all given me some great ideas. I'm a computer scientist so tell me what's wrong with this? Can't I just use a high quality APC backup power system like we use to power racks of gear in our Telco and compute closets? A good one runs the full AC load the rack runs on. I've had maybe one or two short power outages in the last year and half at this house. The worst was less than a couple hours. Wouldn't it be good to put the few linear power supplies I want to keep on connected to the UPS. If I lost the counters or the DMM or really even the computers it's not that big of a deal isn't it the oscillators and OCXO's and their power supplies that really need to stay on? If I reduce the must have to them isn't it really all I need? I can restart the monitoring and computers. Ok so maybe I might get a small gap in data but the key is keeping the power supplies that drive the oscillators and their ovens running right? Thanks, Bill ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
For what it is worth I ran two identical AGM 12 volt batteries for approx 7 years or so in my home lab. I carefully adjusted the terminal voltage while float charging them via a blocking diode and checked the voltage every few months. I also confirmed that the terminal voltage of each 12 volt battery was essentially the same. The manufacturer provided data re suitable float voltages at various temperatures. The temperature in my time lab is fairly stable. After over six years of service they powered two of my OCXO's for approx 48 hours during a lengthy power outage when I was not home. It all worked as I expected (I had chosen the batteries to provide at least 48 hours of run time with some margin) and after approx 7 years I had to replace the batteries when it became apparent they were not charging (the power supply I charge them with has an ammeter which helped me realize there was an issue.) I expect to get a similar life span from the replacement batteries. The second set of batteries at first had a significantly higher voltage difference when being float charged, the battery vendor replaced either one or both of the batteries and all was good. I would not be surprised if the deep discharge of the first set of batteries contributed to their subsequent demise. The experience of others may differ from mine (: Mark Spencer m...@alignedsolutions.com 604 762 4099 > On Sep 25, 2020, at 2:06 PM, Poul-Henning Kamp wrote: > > > Bob kb8tq writes: > >> Two basic types of SLA / VRLA batteries out there: AGM and Gel. For the AGM >> variety, you want a bit more to your charger. > > Yes, if you buy batteries for N * 100K $money, spending more money > on your charger is a good investment. > > But if you have two batteries doing float-charge/long-run/tiny-load, > in a benign environment in a corner of your lab, the internal > variance between batteries in that same production lot, will > overshadow any imaginable benefit a fancy charger could bring. > >> I haven't worked with Gel cells in a while so they may indeed be easier. > > They are for the same reasons they suffer cyclic use better. > > But for a float/long-run application, it makes absolutely no difference. > > -- > 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. > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
When I was still RVing and wanted an electrically quiet charger I built my own "smart charger: using the guts of an Astron 35A linear power supply with an added uc3906 based controller. I later replaced it with a higher efficiency Iota 30A supply with an IQ4 charge controller. It doesn't hurt that they are based here in Tucson :-) Wes N7WS On 9/25/2020 11:25 AM, John Ackermann N8UR wrote: I've had good luck with Iota brand chargers for 12 and 24 volt... I think they are "DCL" series or something similar. They are available in various amperage and include a smart-charger circuit. I know Amazon sells several models and the prices are in the $100-200 range. One of their selling points is that they are electrically quiet, though I haven't done any real tests, and are designed to work as a regular power supply (ie, they don't flake out if there's no battery load attached. John ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
Larry McDavid writes: > Yes, it would be nice to have a Powerpole option for the Mini-Box > Y-PWR-Hot-Swap-Load-Sharing-Controller identified below, but it would be > even better if it would operate with 48 volt supplies for ex-telecom > equipment. There are tons of chips in that market, precisely because of hotplugging telecom kit. LT makes a lot of it. Another interesting gadget are "smart bypass diodes" for solar panels: https://www.ti.com/product/SM74611 Disadvantage: They cycle between conducting and charging their bias, and I have no idea how noisy that is. Advantage: Packages which can be easily soldered by hand. -- 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. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
Bob kb8tq writes: > Two basic types of SLA / VRLA batteries out there: AGM and Gel. For the AGM > variety, you want a bit more to your charger. Yes, if you buy batteries for N * 100K $money, spending more money on your charger is a good investment. But if you have two batteries doing float-charge/long-run/tiny-load, in a benign environment in a corner of your lab, the internal variance between batteries in that same production lot, will overshadow any imaginable benefit a fancy charger could bring. >I haven't worked with Gel cells in a while so they may indeed be easier. They are for the same reasons they suffer cyclic use better. But for a float/long-run application, it makes absolutely no difference. -- 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. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
Hi Two basic types of SLA / VRLA batteries out there: AGM and Gel. For the AGM variety, you want a bit more to your charger. I haven’t worked with Gel cells in a while so they may indeed be easier. Bob > On Sep 25, 2020, at 4:17 PM, Poul-Henning Kamp wrote: > > > Bob kb8tq writes: > >> Properly charging batteries is a bit complicated. > > With VRLA lead-acids: Not really, constant voltage 2.3V/cell, current > limited to $Ah/10 and you're done. > > For the tonnage of batteries relevant for us, when used indoors, > temperature-compensation and all that is not relevant. > > Charging Lithium on the other hand is several kinds of nightmares, many of > them involving unquenchable flames. > >> One “cute” alternative is to do a battery + boost converter ( = switcher) >> instead. >> [...] >> The advantage of a switcher is obviously efficiency. A fully charged “12V” >> LiFePo4 stack could easily be at 14.8V. >> Fully discharged it might get down to 10.4V. Allowing for that 1.4:1 output >> ratio with a linear regulator means a >> lot of (expensive) battery energy goes up in heat …. > > Yes, for most stuff I would just slap a good isolated DC/DC converter on a > single 12V battery and be done with it. > > But for a BVA I would choose more expensive batteries over switching noise > any day... > > -- > 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. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
Bob kb8tq writes: >Properly charging batteries is a bit complicated. With VRLA lead-acids: Not really, constant voltage 2.3V/cell, current limited to $Ah/10 and you're done. For the tonnage of batteries relevant for us, when used indoors, temperature-compensation and all that is not relevant. Charging Lithium on the other hand is several kinds of nightmares, many of them involving unquenchable flames. >One “cute” alternative is to do a battery + boost converter ( = switcher) >instead. >[...] >The advantage of a switcher is obviously efficiency. A fully charged “12V” >LiFePo4 stack could easily be at 14.8V. >Fully discharged it might get down to 10.4V. Allowing for that 1.4:1 output >ratio with a linear regulator means a >lot of (expensive) battery energy goes up in heat …. Yes, for most stuff I would just slap a good isolated DC/DC converter on a single 12V battery and be done with it. But for a BVA I would choose more expensive batteries over switching noise any day... -- 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. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
Yes, Powerpole connectors are wonderful; I use them extensively and in various color combinations for different voltages. Yes, it would be nice to have a Powerpole option for the Mini-Box Y-PWR-Hot-Swap-Load-Sharing-Controller identified below, but it would be even better if it would operate with 48 volt supplies for ex-telecom equipment. Unfortunately, the current design is rated to only 30 vdc. The board would need redesign and would be larger, which I don't see as a problem. Interesting product, though. Thanks to Poul-Henning for identifying it. Larry On 9/25/2020 4:50 AM, Poul-Henning Kamp wrote: Tom Van Baak writes: May I recommend PowerPole connectors and frequent use of diode-OR. For details see: +1 on the power-polery. I really wish somebody would do a version of this with power-pole: https://www.mini-box.com/Y-PWR-Hot-Swap-Load-Sharing-Controller -- Best wishes, Larry McDavid W6FUB Anaheim, California (SE of Los Angeles, near Disneyland) ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
Mark Spencer writes:
> The bit I am struggling with re using a 24 volt battery system in this
> application is what happens when AC power is removed and the terminal
> voltage of the battery starts to fall.
Don't overengineer your supply (unless you absolutely want to :-)
It looks like the BVA is specified at 24V ±10%, which is 21.6-26.6V.
Nobody says 24 Volt is optimal in that interval, and I have
never been able to measure any difference on any OCXO, as long as
I stayed a few hundred millivolts above the lower limit.
I would run the BVA for a week at 24V, collecting PPS data against
a GPSDO or other suitable source.
Then I would run it for a week at 22V, collecting the same data.
If I could not tell the data from the two runs apart, I would design
a 22V supply.
The BVA is spec'ed at 3W steady state, at 22V that's ~150mA.
In long-run applications you get the name-plate capacity, so two
12V x 15 Ah VRLA blocks would keep your BVA happy for four days,
24Ah would last a week etc.
"Small" come from a lot of dubious manufacturers and which means
badly recycled and impure lead. For a golfcart that doesn't matter,
but it is a big disadvantage in long-run applications like this.
Saving 5 bucks on lead-acid batteries are usually a bad deal in the
long run, but on the other hand, dont say no if serious battery-people
offer you a couple of pre-owned large batteries cheap, just make
sure you can lift them.
Lead-Acid in long-duration applications should not be discharged much
below 1.85 V, and 12 cells times 1.85V = 22.2 Volt. Subtract a
diode drop, and now you know where the 24V±10% spec comes from in
the first place.
At 27.6 V float-charge, your linear regulator will have to deal with
(27.6-22)V * 150mA = .84W.
A LM317 would do a fine job, but you can reduce the voltage drop
and get longer runtime with a PNP based home-brew supply.
The float-charger should be able to power the BVA and also recharge
the battery in less than a day, so with 15Ah blocks, I would aim
for around 1-1.5 ampere.
Your batteries will live longer if they have individual chargers,
so something like a 2x12VAC 40-50W torroid trafo, two bridges, two
caps, two LM317's plus resistors and trimpots will do fine.
Poul-Henning
PS: practical hints:
Your local car-nut-emporium has fuseholders like these for cheap:
https://www.thansen.dk/bil/udstyr/eludstyr/kontakter-ledning-sikring/sikringer/sikringsholdere/sikringsholder-m.-kabel-fladsikring/n-497642816/pn-1939736599
Take two, crimp ring-lugs on one end of them, and bolt them directly
to the battery terminal: one for charger, one for load.
When using them next to batteries, the "contra" diode "backwards
across" the LM317 is mandatory.
"Real" UPS installers often have spare batteries which have been
kept on float-charge but otherwise unused, in case of a failure on
customer site. At end of contract, they dont need them any more.
Telephone people with 2V batteries are interesting too, but their
12V blocks are usually dead by the time the swap them out.
Power-grid people, in particular the nuclear plant people, can also
be a good source very, very good batteries with lots of life in
them still, but be very aware of the weight and the short-circuit
currents.
If you end up with pre-owned liquid electrolyte batteries ("OPzS")
make sure the hydrogen gas can vent safely out of the building.
--
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.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
I've had good luck with Iota brand chargers for 12 and 24 volt... I think they are "DCL" series or something similar. They are available in various amperage and include a smart-charger circuit. I know Amazon sells several models and the prices are in the $100-200 range. One of their selling points is that they are electrically quiet, though I haven't done any real tests, and are designed to work as a regular power supply (ie, they don't flake out if there's no battery load attached. John On 9/25/20 1:22 PM, Bob kb8tq wrote: Hi Properly charging batteries is a bit complicated. Why does “properly” matter? You want them to be fully charged, but not damage them in the process. That generally involves some sort of variable voltage for the charging source. If you decide to go with Lithium based parts, you can get BMS (battery management) IC’s that can help with the charging and the balancing ( = you want them all at equal voltages) of the cells. If you look at older gear, this sort of thing didn’t get a lot of attention. Most of the backup battery setups worked poorly as a result. == One “cute” alternative is to do a battery + boost converter ( = switcher) instead. If the device only operates during a power outage, noise is not a big deal. Everything that is attached to the OCXO output is dead anyway …. The advantage of a switcher is obviously efficiency. A fully charged “12V” LiFePo4 stack could easily be at 14.8V. Fully discharged it might get down to 10.4V. Allowing for that 1.4:1 output ratio with a linear regulator means a lot of (expensive) battery energy goes up in heat …. Bob On Sep 25, 2020, at 11:55 AM, Mark Spencer wrote: Pondering the backup power issues for my BVA a bit more, I am thinking a dedicated DC battery bank (maybe 5 or 6 nominal 6 volt batteries in series) powering a suitable linear regulator circuit is probably the direction I will go in. I suspect there are more elegant and or simpler approaches but I think from my perspective as a hobbyist this is probably the best direction for me. I like the idea of using a diode arrangement to facilitate changing the power source for the BVA. I expect I will also add some form of over voltage protection as well. I need to ponder the likely voltage drops in the voltage regulator and diodes along with the voltages the batteries will provide as they discharge under load. It seems I have another winter project. Thanks all for the suggestions. Mark Spencer m...@alignedsolutions.com 604 762 4099 On Sep 25, 2020, at 7:16 AM, Magnus Danielson wrote: Hi, On 2020-09-24 23:47, Tom Van Baak wrote: Next time I power down mine is to integrate a new supply and back-up May I recommend PowerPole connectors and frequent use of diode-OR. For details see: http://leapsecond.com/pages/powerpole/diode-or.htm I got the inspiration when my Dad was in the hospital and I saw how they did IV tubes with multiple injection points. It seemed so simple, clever, reliable. Details [1] and graphic photo [2]. So now I use diode-OR "Y" connectors on all my long-term standards. It allows me to replace either power supply live without interruption at any time. Come to think of it, they call it an IV in the hospital. And here in my lab the I is about 0.18 and V is 24 so my IV is 4 watts. ;-) That's how we do it in Telecom, but on the 48V level. I managed to drive my company into do it with 48V all the way to the various boards, because that way the protection switching out there handled multiple faults. Also, for some reason there is this line of DCDC converters from 48V to about anything. We kept doing that since, even if the diodes now been replaced with MOSFETs to lower losses. If you look into say the 5065A that's how it's done there too. As for power-pole, those are great connectors, but I need to keep 12V, 24V and 48V in the lab, so I need to get the different color codes not to interchange them. You usually react when you see a yellow-black trying to mate with a red-black. So, I recommend folks to do the same. Once one got started with the Anderson PowerPole, it becomes more and more a solution. But yeah, thanks for reminding me that I need to progress on the power-pole and power supply projects. I'll do that after the PiDP-11 project. Cheers, ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
Hi Properly charging batteries is a bit complicated. Why does “properly” matter? You want them to be fully charged, but not damage them in the process. That generally involves some sort of variable voltage for the charging source. If you decide to go with Lithium based parts, you can get BMS (battery management) IC’s that can help with the charging and the balancing ( = you want them all at equal voltages) of the cells. If you look at older gear, this sort of thing didn’t get a lot of attention. Most of the backup battery setups worked poorly as a result. == One “cute” alternative is to do a battery + boost converter ( = switcher) instead. If the device only operates during a power outage, noise is not a big deal. Everything that is attached to the OCXO output is dead anyway …. The advantage of a switcher is obviously efficiency. A fully charged “12V” LiFePo4 stack could easily be at 14.8V. Fully discharged it might get down to 10.4V. Allowing for that 1.4:1 output ratio with a linear regulator means a lot of (expensive) battery energy goes up in heat …. Bob > On Sep 25, 2020, at 11:55 AM, Mark Spencer wrote: > > Pondering the backup power issues for my BVA a bit more, I am thinking a > dedicated DC battery bank (maybe 5 or 6 nominal 6 volt batteries in series) > powering a suitable linear regulator circuit is probably the direction I will > go in. I suspect there are more elegant and or simpler approaches but I > think from my perspective as a hobbyist this is probably the best direction > for me. > > I like the idea of using a diode arrangement to facilitate changing the power > source for the BVA. I expect I will also add some form of over voltage > protection as well. > > I need to ponder the likely voltage drops in the voltage regulator and diodes > along with the voltages the batteries will provide as they discharge under > load. > > It seems I have another winter project. > > Thanks all for the suggestions. > > > Mark Spencer > m...@alignedsolutions.com > 604 762 4099 > >> On Sep 25, 2020, at 7:16 AM, Magnus Danielson wrote: >> >> Hi, >> >> On 2020-09-24 23:47, Tom Van Baak wrote: Next time I power down mine is to integrate a new supply and back-up >>> >>> May I recommend PowerPole connectors and frequent use of diode-OR. For >>> details see: >>> >>> http://leapsecond.com/pages/powerpole/diode-or.htm >>> >>> I got the inspiration when my Dad was in the hospital and I saw how >>> they did IV tubes with multiple injection points. It seemed so simple, >>> clever, reliable. Details [1] and graphic photo [2]. >>> >>> So now I use diode-OR "Y" connectors on all my long-term standards. It >>> allows me to replace either power supply live without interruption at >>> any time. Come to think of it, they call it an IV in the hospital. And >>> here in my lab the I is about 0.18 and V is 24 so my IV is 4 watts. ;-) >> That's how we do it in Telecom, but on the 48V level. I managed to drive >> my company into do it with 48V all the way to the various boards, >> because that way the protection switching out there handled multiple >> faults. Also, for some reason there is this line of DCDC converters from >> 48V to about anything. We kept doing that since, even if the diodes now >> been replaced with MOSFETs to lower losses. >> >> If you look into say the 5065A that's how it's done there too. >> >> As for power-pole, those are great connectors, but I need to keep 12V, >> 24V and 48V in the lab, so I need to get the different color codes not >> to interchange them. You usually react when you see a yellow-black >> trying to mate with a red-black. So, I recommend folks to do the same. >> Once one got started with the Anderson PowerPole, it becomes more and >> more a solution. >> >> But yeah, thanks for reminding me that I need to progress on the >> power-pole and power supply projects. I'll do that after the PiDP-11 >> project. >> >> Cheers, >> > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
Hi If you run a straight linear regulator setup, then you *do* indeed have a battery voltage that is (nominally) much higher than the “target” voltage. If you run a diode voting input, then the “normal” voltage will be even higher. You can easily get into the 35 to 40V range doing this. Bob > On Sep 25, 2020, at 1:21 PM, Mark Spencer wrote: > > Thanks Paul. > > The bit I am struggling with re using a 24 volt battery system in this > application is what happens when AC power is removed and the terminal voltage > of the battery starts to fall. > > Between voltage drop in the regulator, the voltage drop in any extra diodes > etc, a nominal 24 volt lead acid battery doesn't seem enough to me if the > goal is to provide the BVA with a stable 24 volt power source for a lengthy > period of time. I acknowledge that one could perhaps decide to run the BVA > from a some what lower voltage and still be within the voltage spec, but I > don't want to do that and in my view that probably won't really solve the > issue if one wants to fully use the capacity of typical lead acid batteries. > (I expect a typical 24 volt lead acid battery system could provide useable > power down to 22 or perhaps even 21 volts ?). The voltage regulator and > diodes will add voltage drop. > > Maybe I am missing something ? (Maybe fancy regulator schemes that > automatically bypass themselves when the input voltage goes below a preset > level ? But from my hobbyist perspective that seems more complicated than > simply using a higher voltage battery system.) > > > > Thanks > > > > Mark Spencer > m...@alignedsolutions.com > 604 762 4099 > >> On Sep 25, 2020, at 10:01 AM, Poul-Henning Kamp wrote: >> >> >> Mark Spencer writes: >> >>> I like the idea of using a diode arrangement to facilitate changing the >>> power >>> source for the BVA. I expect I will also add some form of over voltage >>> protection as well. >> >> If you are after the low noise, be weary of "integrated" lithium batteries >> of 12V and higher, many of them have a built in buck-converter to take the >> real battery voltage down to 12V and provide over-current protection. >> >> If you go lead-acid, don't forget rule #1: >> >> Your fuses can never be too numerous or too close to the battery. >> >> Lead-Acid batteries float-charge at 13.8V[1] so two 12V in series you gets >> you 27.6V. >> >> Subtract the drop over a series diode and add a linear voltage regulator and >> you have nice and quiet 24V. >> >> (A lot of professional fire and burgler-alarms run on such configs, and the >> hardware is actually pretty nice, being a nieche and high-margin business, >> look out for it in scrap-heaps.) >> >> When the charger looses power, you will drop below 24V after some time (1-60 >> minutes depending on battery capacity), but if the rest of your lab is dark >> anyway, that can still keep the BVA warm until power comes again. >> >> If on the other hand you want to disconnect the charger to make low-noise >> measurements running from battery, you will need more voltage headroom. >> >> I would not go with five 6V batteries. 6V batteries are almost universally >> lower quality than 12V, probably because nobody "serious" uses them, so >> manufacturers do not get yelled about on quality. >> >> Three 12V blocks will put you at 41.4V when float-charging, which is a lot >> to swallow for a linear regulator, both in terms of voltage and power. >> >> Poul-Henning >> >> [1] Tons of footnotes on this but find and trust the manufacturer is a very >> good starting point, unless you want yet another hobby. >> >> -- >> 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. >> > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
Thanks Paul. The bit I am struggling with re using a 24 volt battery system in this application is what happens when AC power is removed and the terminal voltage of the battery starts to fall. Between voltage drop in the regulator, the voltage drop in any extra diodes etc, a nominal 24 volt lead acid battery doesn't seem enough to me if the goal is to provide the BVA with a stable 24 volt power source for a lengthy period of time. I acknowledge that one could perhaps decide to run the BVA from a some what lower voltage and still be within the voltage spec, but I don't want to do that and in my view that probably won't really solve the issue if one wants to fully use the capacity of typical lead acid batteries. (I expect a typical 24 volt lead acid battery system could provide useable power down to 22 or perhaps even 21 volts ?). The voltage regulator and diodes will add voltage drop. Maybe I am missing something ? (Maybe fancy regulator schemes that automatically bypass themselves when the input voltage goes below a preset level ? But from my hobbyist perspective that seems more complicated than simply using a higher voltage battery system.) Thanks Mark Spencer m...@alignedsolutions.com 604 762 4099 > On Sep 25, 2020, at 10:01 AM, Poul-Henning Kamp wrote: > > > Mark Spencer writes: > >> I like the idea of using a diode arrangement to facilitate changing the power >> source for the BVA. I expect I will also add some form of over voltage >> protection as well. > > If you are after the low noise, be weary of "integrated" lithium batteries of > 12V and higher, many of them have a built in buck-converter to take the real > battery voltage down to 12V and provide over-current protection. > > If you go lead-acid, don't forget rule #1: > > Your fuses can never be too numerous or too close to the battery. > > Lead-Acid batteries float-charge at 13.8V[1] so two 12V in series you gets > you 27.6V. > > Subtract the drop over a series diode and add a linear voltage regulator and > you have nice and quiet 24V. > > (A lot of professional fire and burgler-alarms run on such configs, and the > hardware is actually pretty nice, being a nieche and high-margin business, > look out for it in scrap-heaps.) > > When the charger looses power, you will drop below 24V after some time (1-60 > minutes depending on battery capacity), but if the rest of your lab is dark > anyway, that can still keep the BVA warm until power comes again. > > If on the other hand you want to disconnect the charger to make low-noise > measurements running from battery, you will need more voltage headroom. > > I would not go with five 6V batteries. 6V batteries are almost universally > lower quality than 12V, probably because nobody "serious" uses them, so > manufacturers do not get yelled about on quality. > > Three 12V blocks will put you at 41.4V when float-charging, which is a lot to > swallow for a linear regulator, both in terms of voltage and power. > > Poul-Henning > > [1] Tons of footnotes on this but find and trust the manufacturer is a very > good starting point, unless you want yet another hobby. > > -- > 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. > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
Mark Spencer writes: > I like the idea of using a diode arrangement to facilitate changing the power > source for the BVA. I expect I will also add some form of over voltage > protection as well. If you are after the low noise, be weary of "integrated" lithium batteries of 12V and higher, many of them have a built in buck-converter to take the real battery voltage down to 12V and provide over-current protection. If you go lead-acid, don't forget rule #1: Your fuses can never be too numerous or too close to the battery. Lead-Acid batteries float-charge at 13.8V[1] so two 12V in series you gets you 27.6V. Subtract the drop over a series diode and add a linear voltage regulator and you have nice and quiet 24V. (A lot of professional fire and burgler-alarms run on such configs, and the hardware is actually pretty nice, being a nieche and high-margin business, look out for it in scrap-heaps.) When the charger looses power, you will drop below 24V after some time (1-60 minutes depending on battery capacity), but if the rest of your lab is dark anyway, that can still keep the BVA warm until power comes again. If on the other hand you want to disconnect the charger to make low-noise measurements running from battery, you will need more voltage headroom. I would not go with five 6V batteries. 6V batteries are almost universally lower quality than 12V, probably because nobody "serious" uses them, so manufacturers do not get yelled about on quality. Three 12V blocks will put you at 41.4V when float-charging, which is a lot to swallow for a linear regulator, both in terms of voltage and power. Poul-Henning [1] Tons of footnotes on this but find and trust the manufacturer is a very good starting point, unless you want yet another hobby. -- 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. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
Pondering the backup power issues for my BVA a bit more, I am thinking a dedicated DC battery bank (maybe 5 or 6 nominal 6 volt batteries in series) powering a suitable linear regulator circuit is probably the direction I will go in. I suspect there are more elegant and or simpler approaches but I think from my perspective as a hobbyist this is probably the best direction for me. I like the idea of using a diode arrangement to facilitate changing the power source for the BVA. I expect I will also add some form of over voltage protection as well. I need to ponder the likely voltage drops in the voltage regulator and diodes along with the voltages the batteries will provide as they discharge under load. It seems I have another winter project. Thanks all for the suggestions. Mark Spencer m...@alignedsolutions.com 604 762 4099 > On Sep 25, 2020, at 7:16 AM, Magnus Danielson wrote: > > Hi, > > On 2020-09-24 23:47, Tom Van Baak wrote: >>> Next time I power down mine is to integrate a new supply and back-up >> >> May I recommend PowerPole connectors and frequent use of diode-OR. For >> details see: >> >> http://leapsecond.com/pages/powerpole/diode-or.htm >> >> I got the inspiration when my Dad was in the hospital and I saw how >> they did IV tubes with multiple injection points. It seemed so simple, >> clever, reliable. Details [1] and graphic photo [2]. >> >> So now I use diode-OR "Y" connectors on all my long-term standards. It >> allows me to replace either power supply live without interruption at >> any time. Come to think of it, they call it an IV in the hospital. And >> here in my lab the I is about 0.18 and V is 24 so my IV is 4 watts. ;-) > That's how we do it in Telecom, but on the 48V level. I managed to drive > my company into do it with 48V all the way to the various boards, > because that way the protection switching out there handled multiple > faults. Also, for some reason there is this line of DCDC converters from > 48V to about anything. We kept doing that since, even if the diodes now > been replaced with MOSFETs to lower losses. > > If you look into say the 5065A that's how it's done there too. > > As for power-pole, those are great connectors, but I need to keep 12V, > 24V and 48V in the lab, so I need to get the different color codes not > to interchange them. You usually react when you see a yellow-black > trying to mate with a red-black. So, I recommend folks to do the same. > Once one got started with the Anderson PowerPole, it becomes more and > more a solution. > > But yeah, thanks for reminding me that I need to progress on the > power-pole and power supply projects. I'll do that after the PiDP-11 > project. > > Cheers, > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
Hi, On 2020-09-24 23:47, Tom Van Baak wrote: > > Next time I power down mine is to integrate a new supply and back-up > > May I recommend PowerPole connectors and frequent use of diode-OR. For > details see: > > http://leapsecond.com/pages/powerpole/diode-or.htm > > I got the inspiration when my Dad was in the hospital and I saw how > they did IV tubes with multiple injection points. It seemed so simple, > clever, reliable. Details [1] and graphic photo [2]. > > So now I use diode-OR "Y" connectors on all my long-term standards. It > allows me to replace either power supply live without interruption at > any time. Come to think of it, they call it an IV in the hospital. And > here in my lab the I is about 0.18 and V is 24 so my IV is 4 watts. ;-) > That's how we do it in Telecom, but on the 48V level. I managed to drive my company into do it with 48V all the way to the various boards, because that way the protection switching out there handled multiple faults. Also, for some reason there is this line of DCDC converters from 48V to about anything. We kept doing that since, even if the diodes now been replaced with MOSFETs to lower losses. If you look into say the 5065A that's how it's done there too. As for power-pole, those are great connectors, but I need to keep 12V, 24V and 48V in the lab, so I need to get the different color codes not to interchange them. You usually react when you see a yellow-black trying to mate with a red-black. So, I recommend folks to do the same. Once one got started with the Anderson PowerPole, it becomes more and more a solution. But yeah, thanks for reminding me that I need to progress on the power-pole and power supply projects. I'll do that after the PiDP-11 project. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
Hi How often do you loose power? If it’s once a year for < 1 hour …. how big an issue is this to you? Do you *need* to do precision measurements every day? Is restarting a run once a year a major issue? Option one is to simply restart after an outage. Option two is to protect against it. To protect a full bench setup, some sort of UPS is going to be needed. With counters and all the other “stuff” there really is no other practical approach. That immediately gets to how much power for how long. A bench that pulls 800W and a typical outage of 4 hours is going to mean a pretty big battery pack on the UPS. If you go shopping and expect a typical outage of 4 hours, shop for something rated at 6 hours (at your power level). If the bench appears to pull 800W go for something >= 1,200W continuous duty. For a variety of reasons, you need to have some >“margin” in both numbers. When you get into run time dimensioned in hours, things get nutty expensive. A generator (natural gas or propane powered) with an auto start is often the lower cost approach compared to giant batteries. You still need the UPS, but it only has to run for a few minutes while the generator fires up. == In the house before this one, the generator *was* the way to go. That neighborhood was deep in the woods. If a big storm blew in off the ocean and a lot of trees went down, our little cluster of houses was not very high on the list for repair. We could be out for a week or more every couple years. An outage of > 2 hours was pretty normal several times a year. = When we first moved in here, the main feed line into town had “issues”. Just about any time of year, a modest amount of wind could shut down the feed line. It was reasonable to expect multiple outages a month. In the windy months multiple outages a day did happen. As a result, we had a *lot* of UPS’s scattered around the house. The outages were mostly in the 5 seconds to two minutes range. Very normal UPS units did the trick. A convenient tornado came through a few years ago. It took out about 1/3 of the feed line and the sub-station feeding the line. As a result they replaced the entire feed line. Since then, there has been very little need for the UPS fleet. One aspect of keeping a heavily used setup running is wear and tear on the batteries. They don’t last as long as you might hope they would, at least not to anywhere near the full capacity rating. Going to LIthium’s instead of sealed lead acid’s might help this, but at a pretty steep price up front. Are they cheaper long term? We’ll know in 20 years …. :) Bob > On Sep 25, 2020, at 12:27 AM, Bill Notfaded wrote: > > I plan to keep BVA powered. My question was how do you accomplish this and > what do you do it with? I've been using PS like for example Fluke > PM2811, Tekpower TP3005T, Dr. Meter HY3005F-3 (these are similar), Sorensen > and some older HP. I've had good luck them all so far. I'm curious if > someone's found some better way that's smaller and newer and still good? > It looks like a big UPS is in my future. Luckily I rarely have power > outages here even in the desert of the southwest in AZ where the temp and > even humidity is mostly stable inside in the AC in summer and even heat in > the winter. It's dry in both cases inside in my lab. > > Do you monitor the thermistor along with the frequency and external > temperature/humidty? I've been using this for external: > > http://www.dogratian.com/products/index.php/menu-sensors/menu-usb-pa-type-a-bmp085 > > It seems to work pretty well to monitor temp and humidity with USB for the > room plugged into my computer. > > What I'm starting to think about is how do this on much larger scale at the > same time? I have a few counters 53131, 53132, CNT-90, and an SRS SR620 > but how do you do long term measurements over long extended periods on > multiple powered up oscillators? Is there a mass way to do this? I know > the computer could handle this with GPIB but is there another better way to > say monitor all these variables on say 5 to 10 DUT constantly easier? I > have an HP3458A but I wouldn't want to keep it tied up too long. The > counters I run a lot so that's not a problem really. What do you > orchestrate the whole thing with? I have labview NXG but I'm not sure some > hardware DAQ or something with some scripts might not be better for > multiple DUT than messing with labview running all the time. > > How do you do it? How do you get stats on multiple oscillators for years? > I suppose some oscillators deserve their own dedicated counter 24*7 and > maybe even a raspberry pi to sample the GPIB. I do have a few USB to GPIB > interfaces and Pi's are pretty cheap but I've only got a 2 and a 3 right > now. But then is there a timelab for Linux? > > I suppose the first main key is to just keep all the OCXO and GPSDO's > powered all the time first on a UPS? > > Thanks, > > Bill >
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
Bill, most modern double-oven OCXO's (including I think the BVA under discussion) are under 5W average consumption after warmed up. Most UPS's are rated for near-peak-power output (most of a kW or more) for 5 or 10 minutes to give time to shut computers down gracefully and are not sized well for keeping a single 5W device powered up for hours (days? depends on your requirement) although you can use them that way with a substantial loss of efficiency. Figure out your needed hang-time, and size 24V gel-cell or AGM battery to keep the OCXO's ovens warm and oscillator humming. Diode-or'ing works well and if you need to account for a 24V gel cell really being 28V under float charge, use multiple series diodes in that leg to get voltage drop to it being under 24V. The spec about frequency shifting under Voltage change is not really relevant if you aren't using the output during the power outage. You just want to keep the oscillator ticking and ovens warm to prevent having to re-age after an outage. Tim N3QE On Fri, Sep 25, 2020 at 3:38 AM Bill Notfaded wrote: > I plan to keep BVA powered. My question was how do you accomplish this and > what do you do it with? I've been using PS like for example Fluke > PM2811, Tekpower TP3005T, Dr. Meter HY3005F-3 (these are similar), Sorensen > and some older HP. I've had good luck them all so far. I'm curious if > someone's found some better way that's smaller and newer and still good? > It looks like a big UPS is in my future. Luckily I rarely have power > outages here even in the desert of the southwest in AZ where the temp and > even humidity is mostly stable inside in the AC in summer and even heat in > the winter. It's dry in both cases inside in my lab. > > Do you monitor the thermistor along with the frequency and external > temperature/humidty? I've been using this for external: > > > http://www.dogratian.com/products/index.php/menu-sensors/menu-usb-pa-type-a-bmp085 > > It seems to work pretty well to monitor temp and humidity with USB for the > room plugged into my computer. > > What I'm starting to think about is how do this on much larger scale at the > same time? I have a few counters 53131, 53132, CNT-90, and an SRS SR620 > but how do you do long term measurements over long extended periods on > multiple powered up oscillators? Is there a mass way to do this? I know > the computer could handle this with GPIB but is there another better way to > say monitor all these variables on say 5 to 10 DUT constantly easier? I > have an HP3458A but I wouldn't want to keep it tied up too long. The > counters I run a lot so that's not a problem really. What do you > orchestrate the whole thing with? I have labview NXG but I'm not sure some > hardware DAQ or something with some scripts might not be better for > multiple DUT than messing with labview running all the time. > > How do you do it? How do you get stats on multiple oscillators for years? > I suppose some oscillators deserve their own dedicated counter 24*7 and > maybe even a raspberry pi to sample the GPIB. I do have a few USB to GPIB > interfaces and Pi's are pretty cheap but I've only got a 2 and a 3 right > now. But then is there a timelab for Linux? > > I suppose the first main key is to just keep all the OCXO and GPSDO's > powered all the time first on a UPS? > > Thanks, > > Bill > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
Tom Van Baak writes: > May I recommend PowerPole connectors and frequent use of diode-OR. For > details see: +1 on the power-polery. I really wish somebody would do a version of this with power-pole: https://www.mini-box.com/Y-PWR-Hot-Swap-Load-Sharing-Controller -- 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. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
I plan to keep BVA powered. My question was how do you accomplish this and what do you do it with? I've been using PS like for example Fluke PM2811, Tekpower TP3005T, Dr. Meter HY3005F-3 (these are similar), Sorensen and some older HP. I've had good luck them all so far. I'm curious if someone's found some better way that's smaller and newer and still good? It looks like a big UPS is in my future. Luckily I rarely have power outages here even in the desert of the southwest in AZ where the temp and even humidity is mostly stable inside in the AC in summer and even heat in the winter. It's dry in both cases inside in my lab. Do you monitor the thermistor along with the frequency and external temperature/humidty? I've been using this for external: http://www.dogratian.com/products/index.php/menu-sensors/menu-usb-pa-type-a-bmp085 It seems to work pretty well to monitor temp and humidity with USB for the room plugged into my computer. What I'm starting to think about is how do this on much larger scale at the same time? I have a few counters 53131, 53132, CNT-90, and an SRS SR620 but how do you do long term measurements over long extended periods on multiple powered up oscillators? Is there a mass way to do this? I know the computer could handle this with GPIB but is there another better way to say monitor all these variables on say 5 to 10 DUT constantly easier? I have an HP3458A but I wouldn't want to keep it tied up too long. The counters I run a lot so that's not a problem really. What do you orchestrate the whole thing with? I have labview NXG but I'm not sure some hardware DAQ or something with some scripts might not be better for multiple DUT than messing with labview running all the time. How do you do it? How do you get stats on multiple oscillators for years? I suppose some oscillators deserve their own dedicated counter 24*7 and maybe even a raspberry pi to sample the GPIB. I do have a few USB to GPIB interfaces and Pi's are pretty cheap but I've only got a 2 and a 3 right now. But then is there a timelab for Linux? I suppose the first main key is to just keep all the OCXO and GPSDO's powered all the time first on a UPS? Thanks, Bill ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
Thanks Bob that is helpful. The external regulator approach you mention was the direction I was headed in for powering the BVA, but I realized that I would need more than 24 volts into a simple linear regulator to get a stable 24 volt output which complicated using my existing 24 volt battery system. Maybe I am over thinking this. For now I run the BVA as needed from a lab supply that is powered by a UPS. A better backup scheme is something else to look at down the road as I get back into the time nuts hobby. I really appreciate my FTS1050 and HP105B with their separate AC and DC power connections in this regard. Mark Spencer m...@alignedsolutions.com 604 762 4099 > On Sep 24, 2020, at 3:30 PM, Bob kb8tq wrote: > > Hi > > Maximize life = put it on the shelf and *never* power it up. It (may) last > for a century that way. > How you will *know* it’s still doing fine is very unclear. > > Maximize utility = power it up and keep it on power all the time. If you can > plan well, power it > up 9 months before you need to use it. > > There is a lot of data suggesting that > 90 days of stabilization is a good > idea on OCXO’s. > That’s based on fairly basic parts. On something fancy, it’s a good bet that > even longer is better. > > === > > Does it need to be on power at 24V +/- 0.0001 V for 9 months ahead of > time? Is a 1 hour > power outage 3 months back a really big deal? Both are in the “that depends” > category. > Good bet is “don’t worry about it.” > > One practical approach is to mount a regulator external to (and thermally > isolated from) the > OCXO. Then apply whatever supply you happen to have. Net result is that the > device does > not see any crazy voltage spikes. A diode “voting” setup could also be > integrated into the > regulator board. > > Bob > >> On Sep 24, 2020, at 4:47 PM, Mark Spencer wrote: >> >> Hi All. I have a related question.. >> >> From a maximizing the life span of the BVA perspective if one only wants to >> use it once a year or so and can wait for a month or so for it to stabilize, >> does it make more sense to mostly leave it powered down or is leaving it >> running all the time a better plan ? I realize this type of question may >> not have an definitive answer but I am curious about the views of others. >> >> I have a couple of other OCXO's that I leave running all the time and have >> never quite gotten around to putting together a guaranteed to never go down >> DC supply for my BVA. My read on the voltage specs for my BVA discouraged >> me from simply powering it from my 24 volt DC battery bank that is float >> charged at a somewhat higher voltage when AC power is available. >> >> Given the typical price of a BVA, I don't have a spare BVA in my time lab >> and would like to maximize its life. Over the years several other pieces of >> gear have failed but I have spares for them (: >> >> Thanks in advance for any comments. >> >> Mark Spencer >> m...@alignedsolutions.com >> 604 762 4099 >> >>> On Sep 24, 2020, at 12:38 PM, Magnus Danielson http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
What power supply do you recommend for the BVA. I'm kinda partial to high quality linear power supplies. I'm not so concerned about the size or the efficiency. I'm more concerned with clean power that's stable like the oscillators I'm trying to power. I'd be interested in what others think? I know you can often get by with a switching power supply for some things and many OCXO and GPSDO's have they're own power filtering and smoothing to some degree. Bill On Thu, Sep 24, 2020, 12:46 PM Magnus Danielson wrote: > Hi Tom, > > I second this, these oscillators you want to power up and just leave for > them to settle and then keep powered. > > Next time I power down mine is to integrate a new supply and back-up > batteries, which can be a recommended little exercise. Currently only > the H-maser is on battery backup. > > Cheers, > Magnus > > On 2020-09-24 01:25, Tom Van Baak wrote: > > James Robbins wrote: > > > > > Oscilloquartz BVA has been sold. > > > > To the time nut who ended up with this BVA -- do not worry if it looks > > like it is broken when you power it up. These oscillators take their > > time to warm up. Here is a test I did last year on a similar BVA > > oscillator: > > > > "Oscilloquartz 8600-series OCXO warm-up" > > http://leapsecond.com/pages/osa-warm/ > > > > /tvb > > > > > > ___ > > time-nuts mailing list -- time-nuts@lists.febo.com > > To unsubscribe, go to > > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > > and follow the instructions there. > > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
Hi Maximize life = put it on the shelf and *never* power it up. It (may) last for a century that way. How you will *know* it’s still doing fine is very unclear. Maximize utility = power it up and keep it on power all the time. If you can plan well, power it up 9 months before you need to use it. There is a lot of data suggesting that > 90 days of stabilization is a good idea on OCXO’s. That’s based on fairly basic parts. On something fancy, it’s a good bet that even longer is better. === Does it need to be on power at 24V +/- 0.0001 V for 9 months ahead of time? Is a 1 hour power outage 3 months back a really big deal? Both are in the “that depends” category. Good bet is “don’t worry about it.” One practical approach is to mount a regulator external to (and thermally isolated from) the OCXO. Then apply whatever supply you happen to have. Net result is that the device does not see any crazy voltage spikes. A diode “voting” setup could also be integrated into the regulator board. Bob > On Sep 24, 2020, at 4:47 PM, Mark Spencer wrote: > > Hi All. I have a related question.. > > From a maximizing the life span of the BVA perspective if one only wants to > use it once a year or so and can wait for a month or so for it to stabilize, > does it make more sense to mostly leave it powered down or is leaving it > running all the time a better plan ? I realize this type of question may > not have an definitive answer but I am curious about the views of others. > > I have a couple of other OCXO's that I leave running all the time and have > never quite gotten around to putting together a guaranteed to never go down > DC supply for my BVA. My read on the voltage specs for my BVA discouraged > me from simply powering it from my 24 volt DC battery bank that is float > charged at a somewhat higher voltage when AC power is available. > > Given the typical price of a BVA, I don't have a spare BVA in my time lab and > would like to maximize its life. Over the years several other pieces of gear > have failed but I have spares for them (: > > Thanks in advance for any comments. > > Mark Spencer > m...@alignedsolutions.com > 604 762 4099 > >> On Sep 24, 2020, at 12:38 PM, Magnus Danielson wrote: >> >> Hi Tom, >> >> I second this, these oscillators you want to power up and just leave for >> them to settle and then keep powered. >> >> Next time I power down mine is to integrate a new supply and back-up >> batteries, which can be a recommended little exercise. Currently only >> the H-maser is on battery backup. >> >> Cheers, >> Magnus >> >>> On 2020-09-24 01:25, Tom Van Baak wrote: >>> James Robbins wrote: >>> Oscilloquartz BVA has been sold. >>> >>> To the time nut who ended up with this BVA -- do not worry if it looks >>> like it is broken when you power it up. These oscillators take their >>> time to warm up. Here is a test I did last year on a similar BVA >>> oscillator: >>> >>> "Oscilloquartz 8600-series OCXO warm-up" >>> http://leapsecond.com/pages/osa-warm/ >>> >>> /tvb >>> >>> >>> ___ >>> time-nuts mailing list -- time-nuts@lists.febo.com >>> To unsubscribe, go to >>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >>> and follow the instructions there. >> >> >> ___ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe, go to >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. >> > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
Seconded! I don't have that set up on all my oscillators, but plan to get there. I *do* have things set up so I can remove the 24V battery bank for maintenance and run directly on the AC power. BTW, I've standardized on using orange-black PowerPoles for 24V (red-black for 12/13.8V, green-black for 5V, etc.). West Mountain Radio has 24V distribution panels with over/under voltage monitoring and orange-black connectors. And, if you use PowerPoles, please spring the $30 and get a crimping tool. It makes life so much easier, and connections so much more reliable. John On 9/24/20 5:47 PM, Tom Van Baak wrote: > Next time I power down mine is to integrate a new supply and back-up May I recommend PowerPole connectors and frequent use of diode-OR. For details see: http://leapsecond.com/pages/powerpole/diode-or.htm I got the inspiration when my Dad was in the hospital and I saw how they did IV tubes with multiple injection points. It seemed so simple, clever, reliable. Details [1] and graphic photo [2]. So now I use diode-OR "Y" connectors on all my long-term standards. It allows me to replace either power supply live without interruption at any time. Come to think of it, they call it an IV in the hospital. And here in my lab the I is about 0.18 and V is 24 so my IV is 4 watts. ;-) /tvb [1] https://en.wikipedia.org/wiki/Intravenous_therapy [2] https://en.wikipedia.org/wiki/File:ICU_IV_1.jpg On 9/24/2020 12:38 PM, Magnus Danielson wrote: Hi Tom, I second this, these oscillators you want to power up and just leave for them to settle and then keep powered. Next time I power down mine is to integrate a new supply and back-up batteries, which can be a recommended little exercise. Currently only the H-maser is on battery backup. Cheers, Magnus On 2020-09-24 01:25, Tom Van Baak wrote: James Robbins wrote: Oscilloquartz BVA has been sold. To the time nut who ended up with this BVA -- do not worry if it looks like it is broken when you power it up. These oscillators take their time to warm up. Here is a test I did last year on a similar BVA oscillator: "Oscilloquartz 8600-series OCXO warm-up" http://leapsecond.com/pages/osa-warm/ /tvb ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
> Next time I power down mine is to integrate a new supply and back-up May I recommend PowerPole connectors and frequent use of diode-OR. For details see: http://leapsecond.com/pages/powerpole/diode-or.htm I got the inspiration when my Dad was in the hospital and I saw how they did IV tubes with multiple injection points. It seemed so simple, clever, reliable. Details [1] and graphic photo [2]. So now I use diode-OR "Y" connectors on all my long-term standards. It allows me to replace either power supply live without interruption at any time. Come to think of it, they call it an IV in the hospital. And here in my lab the I is about 0.18 and V is 24 so my IV is 4 watts. ;-) /tvb [1] https://en.wikipedia.org/wiki/Intravenous_therapy [2] https://en.wikipedia.org/wiki/File:ICU_IV_1.jpg On 9/24/2020 12:38 PM, Magnus Danielson wrote: Hi Tom, I second this, these oscillators you want to power up and just leave for them to settle and then keep powered. Next time I power down mine is to integrate a new supply and back-up batteries, which can be a recommended little exercise. Currently only the H-maser is on battery backup. Cheers, Magnus On 2020-09-24 01:25, Tom Van Baak wrote: James Robbins wrote: Oscilloquartz BVA has been sold. To the time nut who ended up with this BVA -- do not worry if it looks like it is broken when you power it up. These oscillators take their time to warm up. Here is a test I did last year on a similar BVA oscillator: "Oscilloquartz 8600-series OCXO warm-up" http://leapsecond.com/pages/osa-warm/ /tvb ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
Hi All. I have a related question.. From a maximizing the life span of the BVA perspective if one only wants to use it once a year or so and can wait for a month or so for it to stabilize, does it make more sense to mostly leave it powered down or is leaving it running all the time a better plan ? I realize this type of question may not have an definitive answer but I am curious about the views of others. I have a couple of other OCXO's that I leave running all the time and have never quite gotten around to putting together a guaranteed to never go down DC supply for my BVA. My read on the voltage specs for my BVA discouraged me from simply powering it from my 24 volt DC battery bank that is float charged at a somewhat higher voltage when AC power is available. Given the typical price of a BVA, I don't have a spare BVA in my time lab and would like to maximize its life. Over the years several other pieces of gear have failed but I have spares for them (: Thanks in advance for any comments. Mark Spencer m...@alignedsolutions.com 604 762 4099 > On Sep 24, 2020, at 12:38 PM, Magnus Danielson wrote: > > Hi Tom, > > I second this, these oscillators you want to power up and just leave for > them to settle and then keep powered. > > Next time I power down mine is to integrate a new supply and back-up > batteries, which can be a recommended little exercise. Currently only > the H-maser is on battery backup. > > Cheers, > Magnus > >> On 2020-09-24 01:25, Tom Van Baak wrote: >> James Robbins wrote: >> >>> Oscilloquartz BVA has been sold. >> >> To the time nut who ended up with this BVA -- do not worry if it looks >> like it is broken when you power it up. These oscillators take their >> time to warm up. Here is a test I did last year on a similar BVA >> oscillator: >> >> "Oscilloquartz 8600-series OCXO warm-up" >> http://leapsecond.com/pages/osa-warm/ >> >> /tvb >> >> >> ___ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe, go to >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. > > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
Hi Tom, I second this, these oscillators you want to power up and just leave for them to settle and then keep powered. Next time I power down mine is to integrate a new supply and back-up batteries, which can be a recommended little exercise. Currently only the H-maser is on battery backup. Cheers, Magnus On 2020-09-24 01:25, Tom Van Baak wrote: > James Robbins wrote: > > > Oscilloquartz BVA has been sold. > > To the time nut who ended up with this BVA -- do not worry if it looks > like it is broken when you power it up. These oscillators take their > time to warm up. Here is a test I did last year on a similar BVA > oscillator: > > "Oscilloquartz 8600-series OCXO warm-up" > http://leapsecond.com/pages/osa-warm/ > > /tvb > > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
Thanks Tom- I really appreciate your comment. I've studied your website closely on this topic. I'm really in awe of the 860x models some of you have access to 8607, 8608 models some with options! I'd probably be considered a newer school timenut/voltnut but... I even collect Nixie tube frequency counters... Separate topic but wow I just love cold cathode display technology and mixed with frequency... well dekatron counters too. Props to Jim for making BVA available here before putting on the auction site! I have mad respect for that. I've found some of the best people here. Best Regards, Bill On Wed, Sep 23, 2020, 4:29 PM Tom Van Baak wrote: > James Robbins wrote: > > > Oscilloquartz BVA has been sold. > > To the time nut who ended up with this BVA -- do not worry if it looks > like it is broken when you power it up. These oscillators take their > time to warm up. Here is a test I did last year on a similar BVA > oscillator: > > "Oscilloquartz 8600-series OCXO warm-up" > http://leapsecond.com/pages/osa-warm/ > > /tvb > > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
James Robbins wrote: > Oscilloquartz BVA has been sold. To the time nut who ended up with this BVA -- do not worry if it looks like it is broken when you power it up. These oscillators take their time to warm up. Here is a test I did last year on a similar BVA oscillator: "Oscilloquartz 8600-series OCXO warm-up" http://leapsecond.com/pages/osa-warm/ /tvb ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
[time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.
___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
