Path: Xl.tags.giganews.com!local-1.nntp.ord.giganews.com!nntp.supernews.com!news.supernews.com.POSTED!not-for-mail NNTP-Posting-Date: Mon, 22 Apr 2024 15:51:50 +0000 From: John Larkin Newsgroups: sci.electronics.design Subject: Re: power supply idea Date: Mon, 22 Apr 2024 08:50:02 -0700 Organization: Highland Tech Reply-To: xx@yy.com Message-ID: References: X-Newsreader: Forte Agent 3.1/32.783 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Lines: 36 X-Trace: sv3-8pqr1CWP1sbxJEZZUDF7ftSnIJo7TT/VVxnQZyp6U41hDPyl+K02c4l4S8l2CH+UNfQeYFZmtar3KkB!B7Hh95lBflkOlZrDWhEAezomLED/abAwe5M+GVupR4x8voZKXq2/lh9rQu1ootycv7H6ckadG4d4!H4bkbA== X-Complaints-To: www.supernews.com/docs/abuse.html X-DMCA-Complaints-To: www.supernews.com/docs/dmca.html X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.40 Bytes: 2552 On Mon, 22 Apr 2024 07:15:22 -0000 (UTC), piglet wrote: >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. I invented a control algorithm. All the buck chips that I know of are all feedback driven, and will slam into either rail if the feedback divider is broken. Blow things up.