Re: [time-nuts] HP5370 power supply measurements

[Clay Autery]

Every box I own has AT LEAST one temp sensor in it...  I often add 10 or
more when redesigning the thermal control for a piece of equipment

__
Clay Autery, KY5G
MONTAC Enterprises
(318) 518-1389

On 7/15/2016 1:40 PM, Orin Eman wrote:
>
> In a given instrument, you may get away with the quieter fan, but how would
> you tell other than putting a thermometer inside and making a before/after
> comparison?
>
> Orin.

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] HP5370 power supply measurements

[Alexander Pummer]

PABST KG in the Black Forest (Germany) made very quite high efficient 
fans, HP used to use these fans for awhile, but the company was sold and 
the quite fans disappeared, the new fans from the new owner   
http://www.ebmpapst.us/en/   are cheaper but not so good


73
KJ6UHN
 Alex

On 7/15/2016 1:25 PM, Tommy Phone wrote:

Some thirty years ago fans for automotive radiator cooling were designed with 7 
unevenly spaced blades to reduce the siren effect yet yield comparable air 
flow. Careful layout and blade sweep back along with an annular ring made it 
entirely feasible to have a statically and dynamically balanced fan as it came 
out of the mold. I always wondered why the folks who make these little fans 
can't figure out how to do that. Maybe getting comparable CFM from a much 
smaller fan violates some Reynolds number requirement for turbulence control.

 From Tom Holmes, N8ZM


On Jul 15, 2016, at 3:52 PM, William H. Fite  wrote:

That is, in fact, precisely how you do it.



On Friday, July 15, 2016, Orin Eman  wrote:

On Fri, Jul 15, 2016 at 10:55 AM, Poul-Henning Kamp >
wrote:



In message <
cany2ixq6onvridofgnfkebqjdkntp7t8kue7boupxjwlcux...@mail.gmail.com

>

, "William H. Fite" writes:

David Kirkby scripsit:

I often here of people replacing fans with quiter ones, but I suspect

that

all they really do is reduce the airflow.

Not necessarily, Dave. The Austrian company, Noctua, for one, makes
extremely quiet fans with excellent airflow.

... at zero pressure differential, which is easy to do (Think: ceiling
fan).



Right.

You have to look at the curves on the data sheet that shows air flow vs.
static pressure (and be careful about the static pressure scale).  I found
that a 'quiet' fan would often be flowing one tenth as much air as the
original fan at the static pressure at which the original fan was rated.

In a given instrument, you may get away with the quieter fan, but how would
you tell other than putting a thermometer inside and making a before/after
comparison?

Orin.
___
time-nuts mailing list -- time-nuts@febo.com 
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.



--
Yes, Black lives do matter.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.


-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2016.0.7688 / Virus Database: 4627/12619 - Release Date: 07/15/16


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] HP5370 power supply measurements

[Alex Pummer]

PABST KG in the Black Forest (Germany) made very quite high efficient 
fans, HP used to use these fans for awhile, but the company was sold and 
the quite fans disappeared, the new fans from the new owner 
http://www.ebmpapst.us/en/ are cheaper but not so quite


73
KJ6UHN
 Alex


On 7/15/2016 1:25 PM, Tommy Phone wrote:

Some thirty years ago fans for automotive radiator cooling were designed with 7 
unevenly spaced blades to reduce the siren effect yet yield comparable air 
flow. Careful layout and blade sweep back along with an annular ring made it 
entirely feasible to have a statically and dynamically balanced fan as it came 
out of the mold. I always wondered why the folks who make these little fans 
can't figure out how to do that. Maybe getting comparable CFM from a much 
smaller fan violates some Reynolds number requirement for turbulence control.

 From Tom Holmes, N8ZM


On Jul 15, 2016, at 3:52 PM, William H. Fite  wrote:

That is, in fact, precisely how you do it.



On Friday, July 15, 2016, Orin Eman  wrote:

On Fri, Jul 15, 2016 at 10:55 AM, Poul-Henning Kamp >
wrote:



In message <
cany2ixq6onvridofgnfkebqjdkntp7t8kue7boupxjwlcux...@mail.gmail.com

>

, "William H. Fite" writes:

David Kirkby scripsit:

I often here of people replacing fans with quiter ones, but I suspect

that

all they really do is reduce the airflow.

Not necessarily, Dave. The Austrian company, Noctua, for one, makes
extremely quiet fans with excellent airflow.

... at zero pressure differential, which is easy to do (Think: ceiling
fan).



Right.

You have to look at the curves on the data sheet that shows air flow vs.
static pressure (and be careful about the static pressure scale).  I found
that a 'quiet' fan would often be flowing one tenth as much air as the
original fan at the static pressure at which the original fan was rated.

In a given instrument, you may get away with the quieter fan, but how would
you tell other than putting a thermometer inside and making a before/after
comparison?

Orin.
___
time-nuts mailing list -- time-nuts@febo.com 
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.



--
Yes, Black lives do matter.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.


-
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2016.0.7688 / Virus Database: 4627/12619 - Release Date: 07/15/16


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] HP5370 power supply measurements

[Bob Camp]

Hi

Back when these pieces of gear were being made “new”, HP Spokane had a 
“fan silencer machine”. They used a strobe and a microphone to identify 
imbalanced
blades and then took chunks out of them. They *claimed* it made the fans 
significantly 
less noisy….Watching it in action on a noisy factory floor … not so clear. 

Bob

> On Jul 15, 2016, at 4:25 PM, Tommy Phone  wrote:
> 
> Some thirty years ago fans for automotive radiator cooling were designed with 
> 7 unevenly spaced blades to reduce the siren effect yet yield comparable air 
> flow. Careful layout and blade sweep back along with an annular ring made it 
> entirely feasible to have a statically and dynamically balanced fan as it 
> came out of the mold. I always wondered why the folks who make these little 
> fans can't figure out how to do that. Maybe getting comparable CFM from a 
> much smaller fan violates some Reynolds number requirement for turbulence 
> control. 
> 
> From Tom Holmes, N8ZM
> 
>> On Jul 15, 2016, at 3:52 PM, William H. Fite  wrote:
>> 
>> That is, in fact, precisely how you do it.
>> 
>> 
>>> On Friday, July 15, 2016, Orin Eman  wrote:
>>> 
>>> On Fri, Jul 15, 2016 at 10:55 AM, Poul-Henning Kamp >> >
>>> wrote:
>>> 
 
 In message <
 cany2ixq6onvridofgnfkebqjdkntp7t8kue7boupxjwlcux...@mail.gmail.com
>>> >
 , "William H. Fite" writes:
> David Kirkby scripsit:
>> 
>> I often here of people replacing fans with quiter ones, but I suspect
 that
>> all they really do is reduce the airflow.
> 
> Not necessarily, Dave. The Austrian company, Noctua, for one, makes
> extremely quiet fans with excellent airflow.
 
 ... at zero pressure differential, which is easy to do (Think: ceiling
 fan).
 
 
>>> 
>>> Right.
>>> 
>>> You have to look at the curves on the data sheet that shows air flow vs.
>>> static pressure (and be careful about the static pressure scale).  I found
>>> that a 'quiet' fan would often be flowing one tenth as much air as the
>>> original fan at the static pressure at which the original fan was rated.
>>> 
>>> In a given instrument, you may get away with the quieter fan, but how would
>>> you tell other than putting a thermometer inside and making a before/after
>>> comparison?
>>> 
>>> Orin.
>>> ___
>>> time-nuts mailing list -- time-nuts@febo.com 
>>> To unsubscribe, go to
>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>>> 
>> 
>> 
>> -- 
>> Yes, Black lives do matter.
>> ___
>> time-nuts mailing list -- time-nuts@febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
> 
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] HP5370 power supply measurements

[Tommy Phone]

Some thirty years ago fans for automotive radiator cooling were designed with 7 
unevenly spaced blades to reduce the siren effect yet yield comparable air 
flow. Careful layout and blade sweep back along with an annular ring made it 
entirely feasible to have a statically and dynamically balanced fan as it came 
out of the mold. I always wondered why the folks who make these little fans 
can't figure out how to do that. Maybe getting comparable CFM from a much 
smaller fan violates some Reynolds number requirement for turbulence control. 

>From Tom Holmes, N8ZM

> On Jul 15, 2016, at 3:52 PM, William H. Fite  wrote:
> 
> That is, in fact, precisely how you do it.
> 
> 
>> On Friday, July 15, 2016, Orin Eman  wrote:
>> 
>> On Fri, Jul 15, 2016 at 10:55 AM, Poul-Henning Kamp > >
>> wrote:
>> 
>>> 
>>> In message <
>>> cany2ixq6onvridofgnfkebqjdkntp7t8kue7boupxjwlcux...@mail.gmail.com
>> >
>>> , "William H. Fite" writes:
 David Kirkby scripsit:
> 
> I often here of people replacing fans with quiter ones, but I suspect
>>> that
> all they really do is reduce the airflow.
 
 Not necessarily, Dave. The Austrian company, Noctua, for one, makes
 extremely quiet fans with excellent airflow.
>>> 
>>> ... at zero pressure differential, which is easy to do (Think: ceiling
>>> fan).
>>> 
>>> 
>> 
>> Right.
>> 
>> You have to look at the curves on the data sheet that shows air flow vs.
>> static pressure (and be careful about the static pressure scale).  I found
>> that a 'quiet' fan would often be flowing one tenth as much air as the
>> original fan at the static pressure at which the original fan was rated.
>> 
>> In a given instrument, you may get away with the quieter fan, but how would
>> you tell other than putting a thermometer inside and making a before/after
>> comparison?
>> 
>> Orin.
>> ___
>> time-nuts mailing list -- time-nuts@febo.com 
>> To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>> 
> 
> 
> -- 
> Yes, Black lives do matter.
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] HP5370 power supply measurements

[Poul-Henning Kamp]

>The fact remains that there are some very quiet equipment fans besides the
>little muffins that sound like drones lifting off.

Yes, there are absolutely big differences between fans of same
physical footprint.

But most of the "so quiet we had to break the laws of nature" fans
aimed at the PC market don't do anything like that, and it would
be a big mistake to use such a fan to replace the HP5370 fan, where
a significant pressure is required.

For attaching to the cooling fins to get some air moving, they're
fine however.

-- 
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@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] HP5370 power supply measurements

[Clay Autery]

Actually, the lion's share of noise heard from a fan is NOT the moving
air, but the turbulence over the fan blades... This is a VERY large
topic that I don't want to bore the list with.

__
Clay Autery, KY5G
MONTAC Enterprises
(318) 518-1389

On 7/15/2016 8:17 AM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote:
>
> I often here of people replacing fans with quiter ones, but I suspect that
> all they really do is reduce the airflow. I believe that most of the noise
> one hears is the movement of the air.  From what I have read, sleve bearing
> fans make a bit less noise than ball bearings fans.  However,  although the
> MTBF of both types is similar at 20 degree C, the MTBF of sleve bearing
> fans decreases quite a bit with only a modest increase in temperature.
>
> Dave.

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] HP5370 power supply measurements

[William H. Fite]

That is, in fact, precisely how you do it.


On Friday, July 15, 2016, Orin Eman  wrote:

> On Fri, Jul 15, 2016 at 10:55 AM, Poul-Henning Kamp  >
> wrote:
>
> > 
> > In message <
> > cany2ixq6onvridofgnfkebqjdkntp7t8kue7boupxjwlcux...@mail.gmail.com
> >
> > , "William H. Fite" writes:
> > >David Kirkby scripsit:
> > >>
> > >> I often here of people replacing fans with quiter ones, but I suspect
> > that
> > >> all they really do is reduce the airflow.
> > >
> > >Not necessarily, Dave. The Austrian company, Noctua, for one, makes
> > >extremely quiet fans with excellent airflow.
> >
> > ... at zero pressure differential, which is easy to do (Think: ceiling
> > fan).
> >
> >
>
> Right.
>
> You have to look at the curves on the data sheet that shows air flow vs.
> static pressure (and be careful about the static pressure scale).  I found
> that a 'quiet' fan would often be flowing one tenth as much air as the
> original fan at the static pressure at which the original fan was rated.
>
> In a given instrument, you may get away with the quieter fan, but how would
> you tell other than putting a thermometer inside and making a before/after
> comparison?
>
> Orin.
> ___
> time-nuts mailing list -- time-nuts@febo.com 
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>


-- 
Yes, Black lives do matter.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] HP5370 power supply measurements

[William H. Fite]

The fact remains that there are some very quiet equipment fans besides the
little muffins that sound like drones lifting off.


On Friday, July 15, 2016, Poul-Henning Kamp  wrote:

> 
> In message <
> cany2ixq6onvridofgnfkebqjdkntp7t8kue7boupxjwlcux...@mail.gmail.com
> >
> , "William H. Fite" writes:
> >David Kirkby scripsit:
> >>
> >> I often here of people replacing fans with quiter ones, but I suspect
> that
> >> all they really do is reduce the airflow.
> >
> >Not necessarily, Dave. The Austrian company, Noctua, for one, makes
> >extremely quiet fans with excellent airflow.
>
> ... at zero pressure differential, which is easy to do (Think: ceiling
> fan).
>
> The hard part is to make fans silently move air when they also have
> to build up pressure to get the air to move places.
>
> This is where the gap between the wings and the frame must be minimized,
> or the pressure will leak out through it.
>
> --
> 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.
>


-- 
Yes, Black lives do matter.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] HP5370 power supply measurements

[Orin Eman]

On Fri, Jul 15, 2016 at 10:55 AM, Poul-Henning Kamp 
wrote:

> 
> In message <
> cany2ixq6onvridofgnfkebqjdkntp7t8kue7boupxjwlcux...@mail.gmail.com>
> , "William H. Fite" writes:
> >David Kirkby scripsit:
> >>
> >> I often here of people replacing fans with quiter ones, but I suspect
> that
> >> all they really do is reduce the airflow.
> >
> >Not necessarily, Dave. The Austrian company, Noctua, for one, makes
> >extremely quiet fans with excellent airflow.
>
> ... at zero pressure differential, which is easy to do (Think: ceiling
> fan).
>
>

Right.

You have to look at the curves on the data sheet that shows air flow vs.
static pressure (and be careful about the static pressure scale).  I found
that a 'quiet' fan would often be flowing one tenth as much air as the
original fan at the static pressure at which the original fan was rated.

In a given instrument, you may get away with the quieter fan, but how would
you tell other than putting a thermometer inside and making a before/after
comparison?

Orin.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] HP5370 power supply measurements

[Charles Steinmetz]

David wrote:


An external fan blowing on the heatsink keeps my
5370s nice and cool, for about $10 each.


So more noise.


You seem to have missed the next sentence, which said they are 
"extremely quiet."  So quiet that I could reduce the noise of the 
internal fan by 20dB and still not be able to tell whether the external 
fan was running without looking at it. [1]  So no, as a practical matter 
there is no additional noise.



Surely one of the main  advantages of the SMPS route is the higher
efficiently means less cooling air is required.  That means less noise.


Two different things.  The internal fan primarily cools the inside of 
the counter, while the power supply heat is developed on the heatsink, 
which is mainly cooled by convection outside the enclosure.  (Yes, the 
heatsink has a couple of little holes in it where air from inside the 
counter blows out -- but that is completely ineffectual at reducing the 
heatsink temperature, and I doubt that's what the designers intended. 
More likely, they were trying to minimize the amount of heat from the 
heatsink that gets inside the box, by providing a path for air to flow 
from the inside, past the heatsink, to the outside -- and at that, the 
holes seem effective.)  So, if you reduce the internal fan airflow, the 
internal circuitry will run hotter even though the power supply pass 
devices won't (much).  Further, if you replace the heatsink-mounted 
regulators with switchers that are located inside the box, you may very 
well put MORE heat load on the internal fan even though the switchers 
are much more efficient (because what loss there is would be dissipated 
inside the box, rather than outside).


Best regards,

Charles

[1]  I actually tried an internal fan that reduced the noise by 22dB, 
but it didn't have sufficient airflow to keep the interior properly cool.



___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

[time-nuts] HP5370 power supply measurements

[Mark Sims]

The noise of a turbulent air flow increases  at the EIGTH power of the 
velocity...  it's one of the largest exponents seen in natural phenomena.

> the linear speed of the air has a lot of effect on the noise  
>   
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] HP5370 power supply measurements

[Poul-Henning Kamp]

In message 
, "William H. Fite" writes:
>David Kirkby scripsit:
>>
>> I often here of people replacing fans with quiter ones, but I suspect that
>> all they really do is reduce the airflow.
>
>Not necessarily, Dave. The Austrian company, Noctua, for one, makes
>extremely quiet fans with excellent airflow.

... at zero pressure differential, which is easy to do (Think: ceiling fan).

The hard part is to make fans silently move air when they also have
to build up pressure to get the air to move places.

This is where the gap between the wings and the frame must be minimized,
or the pressure will leak out through it.

-- 
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@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] HP5370 power supply measurements

[William H. Fite]

David Kirkby scripsit:

>
> I often here of people replacing fans with quiter ones, but I suspect that
> all they really do is reduce the airflow.


Not necessarily, Dave. The Austrian company, Noctua, for one, makes
extremely quiet fans with excellent airflow.

___
> time-nuts mailing list -- time-nuts@febo.com 
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>


-- 
Yes, Black lives do matter.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] HP5370 power supply measurements

[Chuck Harris]

It is important to remember that the fans specified in
most of this equipment are sized so that the instrument
can operate safely, in a rack full of equipment, at the
maximum temperature rating for the instrument.

If you plan to run at a comfortable room temperature,
you can usually get by with a much smaller fan.

It might be nice to leave a label somewhere that says
what you did, so the next owner won't be unpleasantly
surprised by it failing in his desert tent.

-Chuck Harris

Dr. David Kirkby (Kirkby Microwave Ltd) wrote:
> On 13 Jul 2016 08:31, "Charles Steinmetz"  wrote:
> 
>> An external fan blowing on the heatsink keeps my 5370s nice and cool, for
> about $10 each.
> 
> So more noise.
> 
>> *if the counters were operated 24/7/365*.  I sometimes take data for a
> few months straight, but very, very far from 24/7/365 on average.  So for
> me, break-even would be more like 50 years.
> 
> I don't suppose Poul's main motivation is to reduce his electric bill.
> 
>> Speaking of fan noise -- you can't really get away with replacing the
> internal fan with one that moves less air, so it is hard to find a
> replacement that generates significantly less noise.  If you find one,
> please share the make and model -- all 5370 owners would love to know.
>>
>> Best regards,
>>
>> Charles
> 
> Surely one of the main  advantages of the SMPS route is the higher
> efficiently means less cooling air is required.  That means less noise.
> 
> I often here of people replacing fans with quiter ones, but I suspect that
> all they really do is reduce the airflow. I believe that most of the noise
> one hears is the movement of the air.  From what I have read, sleve bearing
> fans make a bit less noise than ball bearings fans.  However,  although the
> MTBF of both types is similar at 20 degree C, the MTBF of sleve bearing
> fans decreases quite a bit with only a modest increase in temperature.
> 
> Dave.
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> 
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] HP5370 power supply measurements

[jimlux]

On 7/15/16 6:17 AM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote:



I often here of people replacing fans with quiter ones, but I suspect that
all they really do is reduce the airflow. I believe that most of the noise
one hears is the movement of the air.  From what I have read, sleve bearing
fans make a bit less noise than ball bearings fans.  However,  although the
MTBF of both types is similar at 20 degree C, the MTBF of sleve bearing
fans decreases quite a bit with only a modest increase in temperature.



where I used to work, we obsessed about fan noise (motion picture 
industry, you want *quiet* fans with lots of air), and in the course of 
that we bought dozens of small fans of one kind or another.
First, there's huge variation among different fans, all of the same 
general size and kind. there's some general principles, but ultimately, 
you have to buy one of the fans and try it.  You can have 10 different 
4" cooling fans with the same airflow performance and there could be a 
20dB difference in noise.


Larger fan diameter is quieter than smaller for the same total air flow


- the linear speed of the air has a lot of effect on the noise - in 
residential and quiet office space, for HVAC, the guideline is to keep 
the speed below 1000 Linear Feet Per Minute (LFPM in the data sheets). 
It's actually pretty non linear for a variety of reasons: your hearing 
isn't linear, the spectral properties of the "wind noise" change with 
speed, etc.  This also factors into things like shed vortices off the 
blades interacting with the supporting struts, and so forth.  Slower is 
quieter.


- smaller fans have to turn faster, so the blade rate is higher, making 
them noisier (those little 20mm fans that whine - there's not much 
different between those and a small mechanical siren)


- blades and supports interact - there's a whole lore about number of 
blades and number of struts and whether the struts should align on 
intake and exhaust side, etc.  This is basically all done by empiricism: 
each mfr has their own "secret sauce" for how they choose this.


- blade design has an effect, but not trivially analyzeable. In general, 
large pitch, slow turning is better, unless the blade is close to 
stalling, etc.etc.  funky notches in the trailing edge, winglets at the 
end of the blade may or may not help.


- the single most important factor that changes the performance of a fan 
in terms of air flow is how close the end of the blades are to the 
shroud or hole in which it spins. The tighter the better. You can fool 
with curvatures and inlets and outlets and lengths of ducts and all 
that, but the real important one is blade to wall clearance.  Crummy 
bearings and manufacturing tolerances require large clearances which 
lead to poor performance (noise and "flow vs power in")


- bathroom type fans (e.g. shaded pole AC motor with a plastic blade) 
are deliberately made noisy.


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] HP5370 power supply measurements

[Poul-Henning Kamp]

In message 
, "Dr. David Kirkby (Kirkby Microwave Ltd)" writes:

>Surely one of the main  advantages of the SMPS route is the higher
>efficiently means less cooling air is required.  That means less noise.

Apart from a handfull of watts from the rectifiers, the heat you can
avoid with a better power supply is what is dumped into the cooling
fins on the back.


>I often here of people replacing fans with quiter ones, but I suspect that
>all they really do is reduce the airflow. I believe that most of the noise
>one hears is the movement of the air.

In my case the bearing is worn out and rattles.

As far as I can tell it is just a Pabst 80x80x38mm axial fan with
115VAC supply, so this is going to be my attempt at replacing it:

http://dk.rs-online.com/web/p/aksiale-blaesere/2119342/

-- 
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@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] HP5370 power supply measurements

[Dr. David Kirkby (Kirkby Microwave Ltd)]

On 13 Jul 2016 08:31, "Charles Steinmetz"  wrote:

> An external fan blowing on the heatsink keeps my 5370s nice and cool, for
about $10 each.

So more noise.

> *if the counters were operated 24/7/365*.  I sometimes take data for a
few months straight, but very, very far from 24/7/365 on average.  So for
me, break-even would be more like 50 years.

I don't suppose Poul's main motivation is to reduce his electric bill.

> Speaking of fan noise -- you can't really get away with replacing the
internal fan with one that moves less air, so it is hard to find a
replacement that generates significantly less noise.  If you find one,
please share the make and model -- all 5370 owners would love to know.
>
> Best regards,
>
> Charles

Surely one of the main  advantages of the SMPS route is the higher
efficiently means less cooling air is required.  That means less noise.

I often here of people replacing fans with quiter ones, but I suspect that
all they really do is reduce the airflow. I believe that most of the noise
one hears is the movement of the air.  From what I have read, sleve bearing
fans make a bit less noise than ball bearings fans.  However,  although the
MTBF of both types is similar at 20 degree C, the MTBF of sleve bearing
fans decreases quite a bit with only a modest increase in temperature.

Dave.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] HP5370 power supply measurements

[Bob Stewart]

Hi Rami,
I am very interested in your 5370 power conversion.  Can you give us any more 
information as to the model number of the buck regulators you used and where 
you got them.  Did you run into any problems?  Did you make any notes or 
drawings?

Bob -
AE6RV.com

GFS GPSDO list:
groups.yahoo.com/neo/groups/GFS-GPSDOs/info

  From: Rami Vainio <rami.vai...@gmail.com>
 To: Discussion of precise time and frequency measurement <time-nuts@febo.com> 
 Sent: Wednesday, July 13, 2016 10:19 AM
 Subject: Re: [time-nuts] HP5370 power supply measurements
  
Hello, I did SMPS mod to my 5370. If I remember correctly, consumption 
of +5V was ~5A and -5,2V ~7A. I removed original +5/-5,2V linear 
regulators and replaced them with step-down converters. -5,2V side I did 
float original diode bridge and capasitor and put smps module to 
positive rail. I also removed original prom card and put eprom directly 
to cpu card. Power consumption dropped to close 110W. There was no 
visible performance change after mod.


https://dl.dropboxusercontent.com/u/21770339/hp5370_ps_mod.JPG


Ramppa



-- 
      Rami Vainio    OH2LIY
      Email : rami.vai...@gmail.com
      Phone : +358 40 505 8085



On 11.7.2016 21:46, Poul-Henning Kamp wrote:
> Inspired by the recent thread about power trouble, I spent an hour
> to actually measure why the HP5370 gets so warm as it does.
>
> I'm running on 230VAC here, with the 230/240VAC power setting.
>
> With A6 and A7 removed and turned off: PAC= 4.2 W
>
> That is the loss in the transformer and rectifiers, since the "power"
> switch on the HP5370 really isn't that.
>
> Turning it on, PAC= 19.9W
>
> So the fan uses 15.7W.  (it's also noisy, I should find a replacement)
>
> I also measured the four unregulated DC voltages:
>
>     -20V -> 28.9V
>     -10V -> 13.4V
>     +10V -> 13.4V
>     +20V -> 28.9V
>
> Inserting A6 does not change the OFF state PAC measurably.
>
> Turning on however:  PAC = 140 W
>
> Voltages:
>
>     -20V -> 27.5V
>     -10V -> 10.9V
>     +10V -> 11.9V
>     +20V -> 27.1V
>     +15V -> 14.99V
>     -15V -> 15.04V
>     +5V  -> 5.05V
>     -5.2V-> 5.4V
>     +10V -> 10.0009V
>     -20V -> 123mV ripple
>     -10V -> 2.02V ripple
>     +10V -> 960mV ripple
>     +20V -> 312mV ripple
>
> The unregulated busses are still waay over what the schematics
> would have you belive (10/20V).  The ripple on the -10V seems
> pretty high, but the four electrolytic capacitors seem healthy
> enough.
>
> Next I tried measuring the current on the four regulated voltages,
> which all have short-circuit measuring resistors:
>
>     A6 pin  5- 6 188mV, 0.07R 3% -> 2.68A  +5V
>     A6 pin  7- 8 498mV, 0.07R 3% -> 7.11A  -5.2V
>     A6 pin  9-10 109mV, 0.4R  1% ->  .2725A +15V
>     A6 pin 11-12  55mV, 0.4R  1% ->  .1375A -15V
>
> Since I measured this on the bottom of the motherboard, the contact
> and PCB trace resistance to/on A6 is also included so these currents
> are high estimates.
>
> Measuring with a clamp milliamp-meter instead I find:
>
>     +5V  -> 2.2A
>     -5.2V -> 5.5A
>
> Doing the math:
>
>         Brutto    Netto
>     Trafo:    4.2 W    4.2 W
>     Fan:    15.7 W  15.7 W
>     OCXO:    14.0 W  14.0 W  Netto  Brutto
>     -20:      3.8 W    2.1 W  2.1 W  3.8 W
>     -10:    60.0 W  29.0 W  29.0 W  60.0 W
>     +10:    31.9 W  13.4 W  13.4 W  31.9 W
>     +20:      7.4 W    4.1 W  4.1 W  7.4 W
>     
>         137.5 W  82.5 W  48.6 W 103.1 W
>
> Modern efficient DC/DC converters should therefore be able to
> reduce the PAC by about 50W or one third.
>
> I tried load-testing the unregulated busses, and it looks like all
> four of them can be loaded up to about 5A individually before the
> voltage falls out of spec (10/20 V)
>
> So I've been playing around with KICAD and come up with a design
> with three Traco TEN40WIR DC/DC converters (2x2411 + 2423) running
> off the +/- 10V rails, and I'm seriously tempted to try order a
> PCB just to try it out...
>


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.


  
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] HP5370 power supply measurements

[Rami Vainio]

Hello, I did SMPS mod to my 5370. If I remember correctly, consumption 
of +5V was ~5A and -5,2V ~7A. I removed original +5/-5,2V linear 
regulators and replaced them with step-down converters. -5,2V side I did 
float original diode bridge and capasitor and put smps module to 
positive rail. I also removed original prom card and put eprom directly 
to cpu card. Power consumption dropped to close 110W. There was no 
visible performance change after mod.



https://dl.dropboxusercontent.com/u/21770339/hp5370_ps_mod.JPG


Ramppa



--
 Rami VainioOH2LIY
 Email : rami.vai...@gmail.com
 Phone : +358 40 505 8085



On 11.7.2016 21:46, Poul-Henning Kamp wrote:

Inspired by the recent thread about power trouble, I spent an hour
to actually measure why the HP5370 gets so warm as it does.

I'm running on 230VAC here, with the 230/240VAC power setting.

With A6 and A7 removed and turned off: PAC= 4.2 W

That is the loss in the transformer and rectifiers, since the "power"
switch on the HP5370 really isn't that.

Turning it on, PAC= 19.9W

So the fan uses 15.7W.  (it's also noisy, I should find a replacement)

I also measured the four unregulated DC voltages:

-20V -> 28.9V
-10V -> 13.4V
+10V -> 13.4V
+20V -> 28.9V

Inserting A6 does not change the OFF state PAC measurably.

Turning on however:  PAC = 140 W

Voltages:

-20V -> 27.5V
-10V -> 10.9V
+10V -> 11.9V
+20V -> 27.1V
+15V -> 14.99V
-15V -> 15.04V
+5V  -> 5.05V
-5.2V-> 5.4V
+10V -> 10.0009V
-20V -> 123mV ripple
-10V -> 2.02V ripple
+10V -> 960mV ripple
+20V -> 312mV ripple

The unregulated busses are still waay over what the schematics
would have you belive (10/20V).  The ripple on the -10V seems
pretty high, but the four electrolytic capacitors seem healthy
enough.

Next I tried measuring the current on the four regulated voltages,
which all have short-circuit measuring resistors:

A6 pin  5- 6 188mV, 0.07R 3% -> 2.68A   +5V
A6 pin  7- 8 498mV, 0.07R 3% -> 7.11A   -5.2V
A6 pin  9-10 109mV, 0.4R  1% ->  .2725A +15V
A6 pin 11-12  55mV, 0.4R  1% ->  .1375A -15V

Since I measured this on the bottom of the motherboard, the contact
and PCB trace resistance to/on A6 is also included so these currents
are high estimates.

Measuring with a clamp milliamp-meter instead I find:

+5V   -> 2.2A
-5.2V -> 5.5A

Doing the math:

 BruttoNetto
Trafo:4.2 W4.2 W
Fan: 15.7 W   15.7 W
OCXO:14.0 W   14.0 W   Netto  Brutto
-20:  3.8 W2.1 W   2.1 W   3.8 W
-10: 60.0 W   29.0 W  29.0 W  60.0 W
+10: 31.9 W   13.4 W  13.4 W  31.9 W
+20:  7.4 W4.1 W   4.1 W   7.4 W

137.5 W   82.5 W  48.6 W 103.1 W

Modern efficient DC/DC converters should therefore be able to
reduce the PAC by about 50W or one third.

I tried load-testing the unregulated busses, and it looks like all
four of them can be loaded up to about 5A individually before the
voltage falls out of spec (10/20 V)

So I've been playing around with KICAD and come up with a design
with three Traco TEN40WIR DC/DC converters (2x2411 + 2423) running
off the +/- 10V rails, and I'm seriously tempted to try order a
PCB just to try it out...




___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] HP5370 power supply measurements

[Van Horn, David]

Have you tried a 110V shaded pole motor fan?  Only 60Hz magnetic noise, no 
brushless commutation or brushes.

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Mark Sims
Sent: Wednesday, July 13, 2016 9:50 AM
To: time-nuts@febo.com
Subject: [time-nuts] HP5370 power supply measurements

I have replaced the fans in all my 5370's with quiet 12V  (150-250 mA) 
brushless DC fans running off of the 10V rail.   I placed themocouples around 
the inside of the unit and compared before and after temperatures and found no 
significant differences.  I have used several different models of fans... 
whatever the local surplus store had at the time.

I also replaced the fans in my HP16500 logic analyzers  (aka pizza ovens)  with 
much quieter fans.

-

> Speaking of fan noise -- you can't really get away with replacing the
internal fan with one that moves less air, so it is hard to find a replacement 
that generates significantly less noise.  If you find one, 
please share the make and model -- all 5370 owners would love to know.  
  
___
time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to 
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

[time-nuts] HP5370 power supply measurements

[Mark Sims]

I have replaced the fans in all my 5370's with quiet 12V  (150-250 mA) 
brushless DC fans running off of the 10V rail.   I placed themocouples around 
the inside of the unit and compared before and after temperatures and found no 
significant differences.  I have used several different models of fans... 
whatever the local surplus store had at the time.

I also replaced the fans in my HP16500 logic analyzers  (aka pizza ovens)  with 
much quieter fans.

-

> Speaking of fan noise -- you can't really get away with replacing the 
internal fan with one that moves less air, so it is hard to find a 
replacement that generates significantly less noise.  If you find one, 
please share the make and model -- all 5370 owners would love to know.  
  
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] HP5370 power supply measurements

[Bruce Griffiths]

The most effective approach would be to design a replacement with lower jitter 
(< 5ps ) and lower power consumption (< 10W??).The hard/interesting part is the 
higher resolution lower jitter interpolator.Preliminary testing suggests this 
part isnt as difficult as first thought.
As soon (within a month or so??) as I finish repairing a 24" Cassegrain 
secondary mirror mount, I'll get back to this.

Bruce


  From: Charles Steinmetz <csteinm...@yandex.com>
 To: time-nuts@febo.com 
 Sent: Wednesday, 13 July 2016 7:11 PM
 Subject: Re: [time-nuts] HP5370 power supply measurements
   
Poul-Henning wrote:

> So I've been playing around with KICAD and come up with a design
> with three Traco TEN40WIR DC/DC converters (2x2411 + 2423) running
> off the +/- 10V rails, and I'm seriously tempted to try order a
> PCB just to try it out...

Are the Traco converter modules cheaper where you are than here in the 
US?  It looks like the three converters would cost more than $360 here 
-- almost double what I paid for my most expensive 5370B.  I recognize 
that you get a fair amount in the package, but the regulation and noise 
specs -- while OK -- are certainly not stellar.

An external fan blowing on the heatsink keeps my 5370s nice and cool, 
for about $10 each.  The ones I use are 120v, clamp-on types sold for 
making a breeze at a workstation, and are extremely quiet.  The 
heatsinks run barely warm to the touch.

Reducing line consumption by 50w would save about $3 per counter per 
month here, assuming 24/7 usage.  Break-even on the cost of the 
converters would therefore be ten years, *if the counters were operated 
24/7/365*.  I sometimes take data for a few months straight, but very, 
very far from 24/7/365 on average.  So for me, break-even would be more 
like 50 years.  Even if you pay a lot more for electricity than we do 
here, it's still a very long time before you break even.

Speaking of fan noise -- you can't really get away with replacing the 
internal fan with one that moves less air, so it is hard to find a 
replacement that generates significantly less noise.  If you find one, 
please share the make and model -- all 5370 owners would love to know.

Best regards,

Charles


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.


  
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] HP5370 power supply measurements

[Charles Steinmetz]

Poul-Henning wrote:


So I've been playing around with KICAD and come up with a design
with three Traco TEN40WIR DC/DC converters (2x2411 + 2423) running
off the +/- 10V rails, and I'm seriously tempted to try order a
PCB just to try it out...


Are the Traco converter modules cheaper where you are than here in the 
US?  It looks like the three converters would cost more than $360 here 
-- almost double what I paid for my most expensive 5370B.  I recognize 
that you get a fair amount in the package, but the regulation and noise 
specs -- while OK -- are certainly not stellar.


An external fan blowing on the heatsink keeps my 5370s nice and cool, 
for about $10 each.  The ones I use are 120v, clamp-on types sold for 
making a breeze at a workstation, and are extremely quiet.  The 
heatsinks run barely warm to the touch.


Reducing line consumption by 50w would save about $3 per counter per 
month here, assuming 24/7 usage.  Break-even on the cost of the 
converters would therefore be ten years, *if the counters were operated 
24/7/365*.  I sometimes take data for a few months straight, but very, 
very far from 24/7/365 on average.  So for me, break-even would be more 
like 50 years.  Even if you pay a lot more for electricity than we do 
here, it's still a very long time before you break even.


Speaking of fan noise -- you can't really get away with replacing the 
internal fan with one that moves less air, so it is hard to find a 
replacement that generates significantly less noise.  If you find one, 
please share the make and model -- all 5370 owners would love to know.


Best regards,

Charles


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

[time-nuts] HP5370 power supply measurements

[Poul-Henning Kamp]

Inspired by the recent thread about power trouble, I spent an hour
to actually measure why the HP5370 gets so warm as it does.

I'm running on 230VAC here, with the 230/240VAC power setting.

With A6 and A7 removed and turned off: PAC= 4.2 W

That is the loss in the transformer and rectifiers, since the "power"
switch on the HP5370 really isn't that.

Turning it on, PAC= 19.9W

So the fan uses 15.7W.  (it's also noisy, I should find a replacement)

I also measured the four unregulated DC voltages:

-20V -> 28.9V
-10V -> 13.4V
+10V -> 13.4V
+20V -> 28.9V

Inserting A6 does not change the OFF state PAC measurably.

Turning on however:  PAC = 140 W

Voltages:

-20V -> 27.5V
-10V -> 10.9V
+10V -> 11.9V
+20V -> 27.1V
+15V -> 14.99V
-15V -> 15.04V
+5V  -> 5.05V
-5.2V-> 5.4V
+10V -> 10.0009V
-20V -> 123mV ripple
-10V -> 2.02V ripple
+10V -> 960mV ripple
+20V -> 312mV ripple

The unregulated busses are still waay over what the schematics
would have you belive (10/20V).  The ripple on the -10V seems
pretty high, but the four electrolytic capacitors seem healthy
enough.

Next I tried measuring the current on the four regulated voltages,
which all have short-circuit measuring resistors:

A6 pin  5- 6 188mV, 0.07R 3% -> 2.68A   +5V
A6 pin  7- 8 498mV, 0.07R 3% -> 7.11A   -5.2V
A6 pin  9-10 109mV, 0.4R  1% ->  .2725A +15V
A6 pin 11-12  55mV, 0.4R  1% ->  .1375A -15V

Since I measured this on the bottom of the motherboard, the contact
and PCB trace resistance to/on A6 is also included so these currents
are high estimates.

Measuring with a clamp milliamp-meter instead I find:

+5V   -> 2.2A
-5.2V -> 5.5A

Doing the math:

 BruttoNetto 
Trafo:4.2 W4.2 W
Fan: 15.7 W   15.7 W
OCXO:14.0 W   14.0 W   Netto  Brutto
-20:  3.8 W2.1 W   2.1 W   3.8 W
-10: 60.0 W   29.0 W  29.0 W  60.0 W
+10: 31.9 W   13.4 W  13.4 W  31.9 W
+20:  7.4 W4.1 W   4.1 W   7.4 W

137.5 W   82.5 W  48.6 W 103.1 W

Modern efficient DC/DC converters should therefore be able to
reduce the PAC by about 50W or one third.

I tried load-testing the unregulated busses, and it looks like all
four of them can be loaded up to about 5A individually before the
voltage falls out of spec (10/20 V)

So I've been playing around with KICAD and come up with a design
with three Traco TEN40WIR DC/DC converters (2x2411 + 2423) running
off the +/- 10V rails, and I'm seriously tempted to try order a
PCB just to try it out...

-- 
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@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.