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From: rusty@steelmill.cs.umd.edu (Rusty Haddock)
Newsgroups: sci.electronics
Subject: Re: Mind Machine - Need LED Flasher
Message-ID: <32403@mimsy.umd.edu>
Date: 3 Apr 91 15:51:38 GMT
References: <1991Apr03.005649.22625@ddsw1.MCS.COM>
Sender: news@mimsy.umd.edu
Reply-To: rusty@steelmill.cs.umd.edu (Rusty Haddock)
Distribution: sci
Organization: U of Maryland, Dept. of Computer Science, Coll. Pk., MD 20742
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In article <1991Apr03.005649.22625@ddsw1.MCS.COM> whos@ddsw1.MCS.COM (Ben Feen) writes:
   >Help!  I want to make a "Mind machine" type device - 2 pairs of red/green
   >LEDs, arranged thus:
   >
   >	RG           RG
   >
   >a pot to adjust the frequency.  Now - How would I wire something like this?
   >A 555 timer would be perfect for this, but I don't know how to get a
   >symmetrical waveform.  (I am a high school 'lectronics student) He who can

Well... Although I thought you could get a sym wave out of a 555 maybe not --
it's been a while.  Still, there's always running the 555 about 2 times 
faster and running its output through a flip-flop.  Then, no matter how
fast you clock your 555 the output you want will be symmetric.  No?

		-Rusty-
--
Rusty Haddock / CompSci Dept		DOMAIN:	rusty@mimsy.cs.umd.edu
University of Maryland		PATH:	{uunet,rutgers}!mimsy!rusty
    If someone points a quad-vectored, hyper-thermic, cosmo blaster
       at you it's a safe bet that you're about to become toast.