Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!bloom-beacon!apple!oliveb!amdahl!pacbell!ptsfa!dmt
From: dmt@PacBell.COM (Dave Turner)
Newsgroups: sci.electronics
Subject: Re: Timer Ckt - 2 hrs
Message-ID: <4783@ptsfa.PacBell.COM>
Date: 26 Apr 89 19:30:57 GMT
References: <8331@ihlpf.ATT.COM> <25392@amdcad.AMD.COM>
Reply-To: dmt@PacBell.COM (Dave Turner)
Distribution: na
Organization: Pacific * Bell, San Ramon, CA
Lines: 16

In article <25392@amdcad.AMD.COM> rpw3@amdcad.UUCP (Rob Warnock) writes:
|In article <8331@ihlpf.ATT.COM> taizoon@ihlpf.UUCP (Chinwalla,T.) writes:
|| Does anyone have a ckt or recommendation for a chip(s)
|| that is inexpensive and can produce a timing of 120 minutes +- 10 %
|
|I would use a 14-stage CMOS counter chip (4027? 4040? sorry, I forget),
|driven by your favorite 2 Hz oscillator.  It's cheap, and if you feed it
|2.27 Hz, the topmost bit will tick over every two hours.

I don't know how the circuit will be used but this seems to be overkill.

A simple 555 timer seems like it would be sufficient for this.


-- 
Dave Turner	415/542-1299	{att,bellcore,sun,ames,pyramid}!pacbell!dmt