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From: john larkin <JL@gct.com>
Newsgroups: sci.electronics.design
Subject: Re: power supply discharge
Date: Sat, 28 Sep 2024 09:03:01 -0700
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On Sat, 28 Sep 2024 09:46:39 -0400, legg <legg@nospam.magma.ca> wrote:

>On Fri, 27 Sep 2024 10:01:30 -0700, john larkin <jl@glen--canyon.com>
>wrote:
>
>>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.
>
>and this is a surprise because . . . . ?
>
>RL

We always appreciate your valuable insights.