HP5370 power supply measurements
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...
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@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.
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
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 <csteinmetz@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.
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.vainio@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...
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.vainio@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.vainio@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.
On 13 Jul 2016 08:31, "Charles Steinmetz" csteinmetz@yandex.com 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.
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.
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" csteinmetz@yandex.com 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.
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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.
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In message CANX10hCEfL7+svnWXrAzddyAt-rVrEKBjYEg=97fn59FozXQDA@mail.gmail.com
, "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
phk@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.