Re: power supply discharge

On 30-Sept-24 1:21 am, john larkin wrote:

On Sat, 28 Sep 2024 10:21:46 -0700, john larkin <JL@gct.com> wrote:
 

On Sat, 28 Sep 2024 09:44:44 -0400, legg <legg@nospam.magma.ca> wrote:
>

On Fri, 27 Sep 2024 08:07:29 -0700, john larkin <JL@gct.com> wrote:
>

>
Given a benchtop power supply, you can turn the voltage up and then
down, and it goes down. Most have a substantial amount of output
capacitance, and can be driving an external cap too. So something
pulls the output down.
>
I guess that there are no standards for this, but I've never seen a
supply that just hangs high when it's cranked down.
>
I'm designing some programmable multi-channel power suplies and that
is one of many tangled issues in the project.

>
Twiddling the adjustment knob on a bench supply doesn't
represent a dramatic change - and most adjustible
supplies don't load their output terminals with a
lot of capacitance.

>
I've measured a few, and got output terminal capacitance of a few
hundred to maybe 2000 uF.
>
People here might measure some random power supplies. I leave them off
and connect to a 50 ohm sinewave-output function generator and find
the -3 dB point. One could use a square wave and scope the slopes too.
Keeping the amplitude low will avoid turning semi junctions on.

 Come on guys, quit pontificating and start measuring.
 

At this stage in the process, you seem to have some odd constraints. Why the specific h-bridge driver? Why non-isolated?
Sylvia.