Re: HP 6012B volt zero and current regulation
Hello,
all I do know is that Rohde released, some years ago, a
"capacitorless" power supply.
Tam
With best regards
Tam Hanna
---
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On 21.08.2018 00:10, Alan Melia via
Groups.Io wrote:
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One that doesnt give spikes :-))?
Any supply with feedback linear or switcher is a potential
spike producer !
?
I am not up to date in this area
it is possible that slow-start supplies might be best. Other
members may have more ideas.
?
Alan
G3NYK
----- Original Message -----
Sent: Monday, August 20,
2018 10:06 PM
Subject: Re:
[HP-Agilent-Keysight-equipment] HP 6012B volt zero and current
regulation
OK, I'll bite--
What kind of power supply would you recommend?? I always
thought that a regulated supply would be the safest.?
Were these linear or switcher supplies that produced the
spikes?
Thanks,
Dave
On 8/20/2018 2:31 PM, Alan Melia
via Groups.Io wrote:
During 10 years or so doing
life tests on transistors in the 1960s and 70s I would not
use regulated power supplies for powering the devices
during their life test. When asked, I demonstrated the
switch on pulse with a Tek storage scope. ok it was only
microseconds wide but peaked at the unregulated level.~35v
.....enough to damage 24v transistors.This can also happen
with a transcient load. It is to do with the bandwidth of
the feedback loop.
?
Alan
G3NYK
|
The NEW style putty colored and grey colored all plastic injection molded feet used on the more modern HP and later gear are readily available inexpensively on the 'bay.? In my experience, however, the older, hard black plastic ones with the spring loaded metal lock button used on 60s to 70s-ish gear are considerably more difficult to come by, and are also typically much pricier when you can find them.
Of course, I have a lot of older equipment that takes the latter.? They are something I will be exploring the option of printing at some point in the future when I get an FDM printer.
-Pat
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On Mon, Aug 20, 2018 at 11:58 PM, Sergey Kubushyn wrote: On Mon, 20 Aug 2018, Ham Radio wrote:
You can make your own with a 3D printer. ?Check your local Public Library
- they may have free access to a 3D printer. As far as I can tell those are pretty standard HP feet that are abundant on
ePay in any colors. I seriously doubt 3D-printed ones would be any cheaper
not even mentioning their poor quality, not even near original feet...
---
*
* KSI@home KOI8 Net < > The impossible we do immediately. *
* Las Vegas NV, USA < > Miracles require 24-hour notice. *
*
|
At a cost of about an hour per foot on a fast printer.
-Chuck Harris
Kuba Ober wrote:
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20 aug. 2018 kl. 23:58 skrev Sergey Kubushyn <ksi@...>:
On Mon, 20 Aug 2018, Ham Radio wrote:
You can make your own with a 3D printer. Check your local Public Library
- they may have free access to a 3D printer. As far as I can tell those are pretty standard HP feet that are abundant on
ePay in any colors. I seriously doubt 3D-printed ones would be any cheaper
not even mentioning their poor quality, not even near original feet... Sure — injection molded parts are great, but the quality of those feet, when 3D-printed out of something strong like polycarbonate on a reasonably priced printer (~$750 range) would be entirely satisfactory. The layers can be thin and the exterior can be printed slowly to make it look just about perfect.
Discounting printer amortization, the consumables for a set of 4 of those feet would be a few dollars at most. You can get a lot of feet from 1kg of material...
Cheers, Kuba
|
20 aug. 2018 kl. 23:58 skrev Sergey Kubushyn <ksi@...>:
On Mon, 20 Aug 2018, Ham Radio wrote:
You can make your own with a 3D printer. Check your local Public Library
- they may have free access to a 3D printer. As far as I can tell those are pretty standard HP feet that are abundant on
ePay in any colors. I seriously doubt 3D-printed ones would be any cheaper
not even mentioning their poor quality, not even near original feet... Sure — injection molded parts are great, but the quality of those feet, when 3D-printed out of something strong like polycarbonate on a reasonably priced printer (~$750 range) would be entirely satisfactory. The layers can be thin and the exterior can be printed slowly to make it look just about perfect. Discounting printer amortization, the consumables for a set of 4 of those feet would be a few dollars at most. You can get a lot of feet from 1kg of material... Cheers, Kuba
|
On Mon, 20 Aug 2018, Ham Radio wrote: You can make your own with a 3D printer. ?Check your local Public Library
- they may have free access to a 3D printer. As far as I can tell those are pretty standard HP feet that are abundant on ePay in any colors. I seriously doubt 3D-printed ones would be any cheaper not even mentioning their poor quality, not even near original feet... --- * * KSI@home KOI8 Net < > The impossible we do immediately. * * Las Vegas NV, USA < > Miracles require 24-hour notice. * *
|
Thank you Dave,
Ordered them. :-)
Dave
VE7HR
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On Aug 20, 2018, at 8:16 PM, Dave McGuire <mcguire@...> wrote:
On 08/19/2018 11:33 AM, Dave Miller wrote:
Where does one got looking for new feet for the back of a 8672A?
I just unwrapped my recent eBay purchase and its missing 2 of them. eBay:
Unit seem to work and other than a broken off slide switch lever on the
ALC selector I think I am a happy owner of a functional signal generator. Very nice!
-Dave
--
Dave McGuire, AK4HZ
New Kensington, PA
|
Bernie, That is my backup plan. ?I own 2 3D printers. ;-) Would prefer to source real parts. ? Dave
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On Aug 20, 2018, at 8:11 PM, Ham Radio < bernard.murphy@...> wrote: You can make your own with a 3D printer. ?Check your local Public Library - they may have free access to a 3D printer.
73, Bernie, VE3FWF
|
On 08/19/2018 11:33 AM, Dave Miller wrote: Where does one got looking for new feet for the back of a 8672A?
I just unwrapped my recent eBay purchase and its missing 2 of them. eBay: Unit seem to work and other than a broken off slide switch lever on the
ALC selector I think I am a happy owner of a functional signal generator. Very nice! -Dave -- Dave McGuire, AK4HZ New Kensington, PA
|
You can make your own with a 3D printer. ?Check your local Public Library - they may have free access to a 3D printer.
73, Bernie, VE3FWF
|
Re: HP 6012B volt zero and current regulation
I made a constant current load at work, 100 amps 200 volts, of course with a control loop.? When first connected the loop is calling for max current and it made a big current spike.? As this was annoying (making cables jump), I changed it to have a slow start ramp, taking a second to ramp up.? That was pretty easy so I imagine it shouldn't be a problem making a voltage mode supply do the same, and I would expect any decent one to behave that way.
All that was said about control loops is true, you can't get out of that, it's all about the loop bandwidth and also every regulated supply has a particular response, which may be critically, under or over damped.? I have absolutely seen supplies ring in response to a transient load change.? I have also seen really really bad power supply behavior like a 40 volt 20 amp Harrison HP bench supply go severely overvoltage - completely wide open - when a noisy load was applied.? I literally GAVE that supply away.
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On 8/20/2018 6:10 PM, Alan Melia via Groups.Io wrote: ?
One that doesnt give spikes :-)) Any supply with feedback linear or switcher is a potential spike producer !
I am not up to date in this area it is possible that slow-start supplies might be best. Other members may have more ideas.
Alan
G3NYK
----- Original Message -----
*From:* David Speck <mailto:Dave@...>
*To:* [email protected]
<mailto:[email protected]>
*Sent:* Monday, August 20, 2018 10:06 PM
*Subject:* Re: [HP-Agilent-Keysight-equipment] HP 6012B volt zero and
current regulation
OK, I'll bite--
What kind of power supply would you recommend?? I always thought that a
regulated supply would be the safest.
Were these linear or switcher supplies that produced the spikes?
Thanks,
Dave
On 8/20/2018 2:31 PM, Alan Melia via Groups.Io wrote:
During 10 years or so doing life tests on transistors in the 1960s and
70s I would not use regulated power supplies for powering the devices
during their life test. When asked, I demonstrated the switch on pulse
with a Tek storage scope. ok it was only microseconds wide but peaked at
the unregulated level.~35v .....enough to damage 24v transistors.This can
also happen with a transcient load. It is to do with the bandwidth of the
feedback loop.
Alan
G3NYK
|
Re: Joel Kist, was Re: [HP-Agilent-Keysight-equipment] HP 6012B volt zero and current regulation
Dr. David Kirkby from Kirkby Microwave Ltd
The joel-kist@... is the address I wish to keep. Thanks for the help I didn't realize this. - Joel STS SS
I have deleted the other address for you. You should only receive one copy now. Dave
|
Re: Joel Kist, was Re: [HP-Agilent-Keysight-equipment] HP 6012B volt zero and current regulation
The joel-kist@... is the address I wish to keep. Thanks for the help I didn't realize this. - Joel STS SS
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-----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of Dave McGuire Sent: Monday, August 20, 2018 4:44 PM To: [email protected]Subject: Joel Kist, was Re: [HP-Agilent-Keysight-equipment] HP 6012B volt zero and current regulation On 08/20/2018 02:48 PM, Mark Wendt wrote: Off subject – I still get duplicates – Joel
By chance are you subscribed to the group with two different email
addresses? Check the headers of the emails that are dupes the next time
you receive them. Yes, he is. There have been no duplicate messages here. That's a Yahoo problem specifically. Joel, you are subscribed at both your sbcglobal.net address and your att.net address. If you let me know which one you want to keep, I can chop the other one for you. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
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Re: HP 6012B volt zero and current regulation
You’re probably subscribed on two different emails that end up at the same place.?
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Off subject – I still get duplicates – Joel STS SS ? ? I refined my test...
Instead of ramping the voltage with the knob. I basically set the voltage to 20V and the amperage to 2 amps. I connected the voltmeter in series with the bulb and performed a dynamic load test by opening and closing the circuit by touching the probe lead of the voltmeter to the output of the power supply... I also have the Fluke voltmeter set to peak amperage measurement and these are the results that I found.
With the 6012B set to 20V and 2A, upon closing the circuit the peak amps are 4 amps but quickly settles to 2 amps
With the 6024A set to 20V and 2 A, upon closing the circuit the peaks amps are about 2.5 but quickly settles to 2 amps.
The important observation here is the 6012B settles back to 2 amps, it seems the settle time is longer and the deviation is larger than the 6024A. Although these are two completely different supplies If anything I could be nit picking here on the 6012B for its regulation settle time and overshoot, which is why I wanted to see if someone else had a similar supply and could see if they could duplicate the same results to see if this is normal...
Thanks for the help
|
Re: HP 6012B volt zero and current regulation
?
One that doesnt give spikes :-))? Any supply
with feedback linear or switcher is a potential spike producer !
?
I am not up to date in this area it is possible
that slow-start supplies might be best. Other members may have more
ideas.
?
Alan
G3NYK
----- Original Message -----
Sent: Monday, August 20, 2018 10:06
PM
Subject: Re:
[HP-Agilent-Keysight-equipment] HP 6012B volt zero and current
regulation
OK, I'll bite--
What kind of power supply would you recommend?? I always thought that
a regulated supply would be the safest.?
Were these linear or switcher supplies that produced the spikes?
Thanks,
Dave
On 8/20/2018 2:31 PM, Alan Melia via Groups.Io
wrote:
During 10 years or so doing life tests on
transistors in the 1960s and 70s I would not use regulated power supplies
for powering the devices during their life test. When asked, I demonstrated
the switch on pulse with a Tek storage scope. ok it was only microseconds
wide but peaked at the unregulated level.~35v .....enough to damage 24v
transistors.This can also happen with a transcient load. It is to do with
the bandwidth of the feedback loop.
?
Alan
G3NYK
|
Re: 8566B SA all PLLs unlocked
? Fixed one last week … all loops unlocked … bad pass element in the +10 VDC supply. td ?
|
Re: HP 6012B volt zero and current regulation
Hi Dave. I got to thinking a bit about the point Alan made below, and
it's a very good one. If you consider the turn-on behavior of an
unregulated linear supply (i.e. the classic transformer, bridge
rectifier, filter capacitor construct), the shape of the voltage ramp-up
curve should be dominated by the capacitor's charging characteristics.
But if you place a regulator after that, the output voltage (of the
regulator) will rise, and go potentially quite high above the setpoint
until the regulation loop takes over. The width of the waveform above
the setpoint voltage will correspond in inverse proportion to the
bandwidth of the control loop of the regulator.
Linear and switching regulators will both exhibit this behavior,
though modern switching regulators with high switching frequencies and
high-bandwidth control loops will keep it well under control.
In practice this is usually so brief that it doesn't bother anything,
a few dozen microseconds at most. I myself have watched it on an
oscilloscope (I design and characterize a lot of voltage regulators) but
have never seen it do any harm.
-Dave
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On 08/20/2018 05:06 PM, David Speck wrote: OK, I'll bite--
What kind of power supply would you recommend?? I always thought that a
regulated supply would be the safest.?
Were these linear or switcher supplies that produced the spikes?
Thanks,
Dave
On 8/20/2018 2:31 PM, Alan Melia via Groups.Io wrote:
During 10 years or so doing life tests on transistors in the 1960s and
70s I would not use regulated power supplies for powering the devices
during their life test. When asked, I demonstrated the switch on pulse
with a Tek storage scope. ok it was only microseconds wide but peaked
at the unregulated level.~35v .....enough to damage 24v
transistors.This can also happen with a transcient load. It is to do
with the bandwidth of the feedback loop.
?
Alan
G3NYK
--
Dave McGuire, AK4HZ
New Kensington, PA
|
Re: HP 6012B volt zero and current regulation
OK, I'll bite--
What kind of power supply would you recommend?? I always thought
that a regulated supply would be the safest.?
Were these linear or switcher supplies that produced the spikes?
Thanks,
Dave
On 8/20/2018 2:31 PM, Alan Melia via
Groups.Io wrote:
toggle quoted message
Show quoted text
During 10 years or so doing life
tests on transistors in the 1960s and 70s I would not use
regulated power supplies for powering the devices during their
life test. When asked, I demonstrated the switch on pulse with
a Tek storage scope. ok it was only microseconds wide but
peaked at the unregulated level.~35v .....enough to damage 24v
transistors.This can also happen with a transcient load. It is
to do with the bandwidth of the feedback loop.
?
Alan
G3NYK
|
Joel Kist, was Re: [HP-Agilent-Keysight-equipment] HP 6012B volt zero and current regulation
On 08/20/2018 02:48 PM, Mark Wendt wrote: Off subject – I still get duplicates – Joel?
By chance are you subscribed to the group with two different email
addresses? Check the headers of the emails that are dupes the next time
you receive them.? Yes, he is. There have been no duplicate messages here. That's a Yahoo problem specifically. Joel, you are subscribed at both your sbcglobal.net address and your att.net address. If you let me know which one you want to keep, I can chop the other one for you. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
|
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----- Original Message -----
Sent: Monday, August 20, 2018 8:49
PM
Subject: Re:
[HP-Agilent-Keysight-equipment] A huge thank you!
Awesome move... thanks to all involved in it! Bravo!
Phil, N6OMM?
Ditto from me Dave!!!
Jim
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Cubdriver
Sergey Kubushyn
Dave McGuire
Phillip Potter