Path: ...!weretis.net!feeder8.news.weretis.net!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: piglet Newsgroups: sci.electronics.design Subject: Re: power supply idea Date: Mon, 22 Apr 2024 07:15:22 -0000 (UTC) Organization: A noiseless patient Spider Lines: 30 Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Injection-Date: Mon, 22 Apr 2024 09:15:22 +0200 (CEST) Injection-Info: dont-email.me; posting-host="3c3b37ae5eb7d739f9490e3716462808"; logging-data="881117"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1++f/eKGG/f4njtDa/ZeeHA" User-Agent: NewsTap/5.5 (iPhone/iPod Touch) Cancel-Lock: sha1:QoGmXjmFWpQwqE5QVKOv2Pa/VAM= sha1:FNiRtet0bh8qun4eLwsk8ILg2cY= Bytes: 2133 John Larkin wrote: > > If one had, say, a 48 volt power bus, you could hang a half-bridge > switcher to ground, and a lowpass filter out. If the drive has duty > cycle n, the output voltage is 48*n. So we have a programmable power > supply with no feedback, which will be stable into any load. > > The load regulation will be mediocre, but we could almost sell it > as-is. > > So now, sense the output voltage and compute the error against the > target, run through a slowish integrator, and tweak the PWM to get > zero output voltage error. Gross transient response is basically the > response of the output filter, with some modest drool from the > integrator. > > We can constrain the influence range of the integrator, just enough to > give the regulation that we need. That limits output swing in case the > feedback is wrong, as one could get from a botched remote sense > connection. > > https://www.dropbox.com/scl/fi/2fysyvkl4eim7vujhaobh/FFINT_PS_1.jpg?rlkey=rug6yi3cgemi9vvbz8apgboqi&raw=1 > > Looks like you have invented the buck converter. -- piglet