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From: jans@tekgvs.LABS.TEK.COM (Jan Steinman)
Newsgroups: sci.electronics
Subject: Re: A pathetically simple question...
Message-ID: <6028@tekgvs.LABS.TEK.COM>
Date: 29 Sep 89 21:16:37 GMT
Distribution: sci.electronics
Organization: Tektronix Inc., Beaverton, Or.
Lines: 16



Check out the CMOS 4528 dual mono.  These suckers will delay up to *days* with 
careful parts selection.  (your basic 10 Gohm resistor: clean a piece of glass 
with MEK, draw a thin line of india ink on it... the leads are a problem :-)  
They're re-triggerable, and lack a lot of the nasty behavior of the infamous 
555.  Plus, you get two of them in a DIP.  For a 10 second delay, try 10 Mohm 
and 1 uf.  Capacitor leakage current will reduce the effective time constant -- 
use non-electrolytic caps with resistors over half a meg or so.

							   Jan Steinman - N7JDB
						  Electronic Systems Laboratory
					Box 500, MS 50-370, Beaverton, OR 97077
						(w)503/627-5881 (h)503/657-7703