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.
toggle quoted message
Show quoted text
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
