Re: power supply discharge

On Fri, 27 Sep 2024 16:17:42 +0100, liz@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:

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.

>
A DC-coupled audio amplifier chip might work as a fully-controllable
bi-directional power supply if your current and voltage requirements
were fairly modest.  They have the advantage of being relatively cheap,
well-protected and very fast (by power supply standards).  Some of them
have the tab at input earth voltage, so they don't require isolation
from the heat sink.

Unfortunately, it has to be a switching regulator.