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Article #21898Re: Capacitance Meter Stuff (Long)
From: Henry Spencer
Date: Thu, 28 Dec 1989 23:41
Date: Thu, 28 Dec 1989 23:41
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In article <1077@swbatl.UUCP> adams@swbatl.UUCP (4237) writes: >Seems that with a 555, some judicious values of f and careful choice of >value and range of C that an inductance meter is almost trivial if one >can reasonably accurately measure C. Also of relevance: with a 555 and some resistors, plus a frequency counter (which is trivial to build), you *have* a capacitance meter. Just build an RC oscillator and measure the output frequency. Mind you, you need a bit of arithmetic to go from frequency to capacitance, but a $10 calculator solves that unless you're measuring lots of capacitors and speed is important. (Our old electronics wizard, now retired, pointed this out to me during a discussion of cheap test equipment.) It may not give you five-digit accuracy, but capacitor values are seldom that crucial (and can seldom be depended on to be that stable) anyway. -- 1972: Saturn V #15 flight-ready| Henry Spencer at U of Toronto Zoology 1989: birds nesting in engines | uunet!attcan!utzoo!henry henry@zoo.toronto.edu
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Newsgroups: sci.electronics,sci.physics,rec.ham-radio Path: arc1-ca.pugleaf.net!utzoo!henry From: henry@utzoo.uucp (Henry Spencer) Subject: Re: Capacitance Meter Stuff (Long) Message-ID: <1989Dec28.234113.12838@utzoo.uucp> Organization: U of Toronto Zoology References: <1077@swbatl.UUCP> Date: Thu, 28 Dec 89 23:41:13 GMT