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From: KevinJ93 <kevin_es@whitedigs.com>
Newsgroups: sci.electronics.design
Subject: Re: power supply discharge
Date: Sat, 28 Sep 2024 11:56:52 -0700
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On 9/28/24 6:44 AM, legg 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.
> 
> DC coupled programable supplies, or bipolar programmable
> supplies are made to drive loads in the first and third
> quadrants.
> 
> There are issues in the second and fourth quadrants, where
> the supply is expected to absorb power.
> 
> An amplifier driving a pure reactance experiences the same
> losses as driving a dead short.
> 
> RL

Some specialist power supplies for large scale battery testing can 
absorb power and return it to the AC supply.

https://eepower.com/tech-insights/regenerative-power-supplies-create-lots-of-energy-at-electronica/#

kw