Path: ...!Xl.tags.giganews.com!local-2.nntp.ord.giganews.com!nntp.supernews.com!news.supernews.com.POSTED!not-for-mail NNTP-Posting-Date: Mon, 22 Apr 2024 18:11:45 +0000 From: John Larkin Newsgroups: sci.electronics.design Subject: Re: power supply idea Date: Mon, 22 Apr 2024 11:09:57 -0700 Organization: Highland Tech Reply-To: xx@yy.com Message-ID: References: <20240422b@crcomp.net> X-Newsreader: Forte Agent 3.1/32.783 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Lines: 51 X-Trace: sv3-9pV/KH3n71X9U7cfKSq92C/WXda5i0zl/6PtvOHjIiUaa8Ft2ElQBd2z42Lq2ajv+xh+FnUNhS0DHut!qTh92fBbp/XpWnHoDtDQGBzSzc8kJeGdCbXInFNXx4OVC523Oqh+AdPgBIBRS1MJnoCe8MaJeX8X!DkFqkg== 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: 3267 On Mon, 22 Apr 2024 17:38:19 -0000 (UTC), "Don" wrote: >John Larkin wrote: >> erichpwagner 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. > >An algorithm arguably eliminates a 555 triangle generator as a potential >spread spectrum source. LOL. So, what's hidden in plain sight behind all >of your left hand side, symbolic sleight of hand? In other words, how do >you implement your control algorithm? > >Danke, It's all in plain sight. Well, the guts of the PWM converter isn't, but that's pretty obvious. The PWM converter, and in fact everything, will be implemented in an FPGA, with an ADC to pick up the output voltage. May as well go pseudo-random on the spread spectrum part. Any audible side effects would be hiss, not whine.