Path: utzoo!attcan!uunet!husc6!mailrus!ncar!ames!claris!apple!lemke
From: lemke@Apple.COM (Steve Lemke)
Newsgroups: sci.electronics
Subject: Re: Build a "simple" timing device.
Message-ID: <16713@apple.Apple.COM>
Date: 7 Sep 88 05:52:01 GMT
References: <2283@m2-net.UUCP> <16629@apple.Apple.COM> <809@ritcv.UUCP>
Reply-To: lemke@apple.com.UUCP (Steve Lemke)
Organization: Apple Computer Inc, Cupertino, CA
Lines: 19

In article <809@ritcv.UUCP> cep4478@ritcv.UUCP (Christopher E. Piggott) writes:
>Would you explain to me how the delay function works on the 555?  I have a
>few of them, as well as a few of the dual packages (did not know they make a
>quad version), and have been wanting to use one as a burglar alarm entry
>delay, but I don't understand the cooncept of R.C. components and how they
>work (question 1: what are the units, ohms and microfarads?) and how come it
>requires three pins to set the delay?

I don't remember all the specifics (although I've used them before).  Anyway,
you get to control the frequency (assuming astable operation - meaning it will
keep cycling on and off) as well as what part of the cycle it is on (and there-
fore what part it is off).  As I said, I don't remember what the constants are
but if someone has a data book handy perhaps they can look it up for us...

			===== Steve Lemke =====
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