Path: csiph.com!eternal-september.org!feeder.eternal-september.org!nntp.eternal-september.org!.POSTED!not-for-mail From: Christopher Howard Newsgroups: sci.electronics.design Subject: Re: one potentiometer dividing multiple signals Date: Thu, 19 Mar 2026 11:51:16 -0800 Organization: A noiseless patient Spider Lines: 26 Message-ID: <87bjgj38ej.fsf@librehacker.com> References: <87ldfr6bqo.fsf@librehacker.com> <10pch1u$2stub$2@paganini.bofh.team> <878qbp3y0s.fsf@librehacker.com> <10pgr0d$n3c8$2@dont-email.me> MIME-Version: 1.0 Content-Type: text/plain Injection-Date: Thu, 19 Mar 2026 19:51:17 +0000 (UTC) Injection-Info: dont-email.me; posting-host="d2c45e1e985e48f8082c99e4ff514d14"; logging-data="1046834"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX18HtDi4okLywLqsCs3TDGapmaev2uY2OX0=" User-Agent: Gnus/5.13 (Gnus v5.13) Cancel-Lock: sha1:4T0dCXfMGo5y6H18chJfaCgj+Vg= sha1:UAhqZ0szkN6t2Zc3uDm2QWXT1uY= Xref: csiph.com sci.electronics.design:741923 > If you provide a netlist or specimen differential equation then we > could sketch out how to do this in ASCII art or another netlist. I was working on a simplified flight model using angle of attack to calculate lift and drag, and thus vertical and horizontal acceleration. * vertical acceleration is lift force minus gravity force, divided by mass * gravity force is mass times a gravity variable * horizontal acceleration is thrust minus drag force, divided by mass * the horizontal acceleration is integrated to give horizontal velocity which is squared and then fed into the circuit that calculates lift and drag force based on angle of attack (coefficients of lift/drag). Ignoring for the present the detail of different air behavior at different altitudes, and banking. With analog computing, multiplication or division by a constant can be done with a potentiometer, though it is physically speaking a voltage division. It is not obvious to me how combine those three mass related calculations into something done with a single summing amplifier and a single pot, but I am open minded. -- Christopher Howard