Path: ...!news.mixmin.net!news2.arglkargh.de!news.karotte.org!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail From: liz@poppyrecords.invalid.invalid (Liz Tuddenham) Newsgroups: sci.electronics.design Subject: Re: power supply discharge Date: Fri, 27 Sep 2024 16:17:42 +0100 Organization: Poppy Records Lines: 25 Message-ID: <1r0jx0j.1upucutkl7g4iN%liz@poppyrecords.invalid.invalid> References: X-Trace: individual.net 10lnsUFvAQYnOExscQRPBALPNjf5zalpKI6L0+TkIBFm1nRRJ5 X-Orig-Path: liz Cancel-Lock: sha1:P5bekUzRDiwMEUjd8LKEFTnnVSM= sha256:9WstivySEdqH+ii5OalWw3LgkKDnF45bzv8tZ+zfVGU= User-Agent: MacSOUP/2.4.6 Bytes: 1728 john larkin 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. -- ~ Liz Tuddenham ~ (Remove the ".invalid"s and add ".co.uk" to reply) www.poppyrecords.co.uk