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From: whos@ddsw1.MCS.COM (Ben Feen)
Newsgroups: sci.electronics
Subject: Re: LED brightness, colors
Message-ID: <1990Jun29.215920.4003@ddsw1.MCS.COM>
Date: 29 Jun 90 21:59:20 GMT
References: <7644@jarthur.Claremont.EDU>
Reply-To: whos@ddsw1.MCS.COM (Ben Feen)
Distribution: na
Organization: ddsw1.MCS.COM Contributor, Wheeling, IL
Lines: 31

In article <7644@jarthur.Claremont.EDU> rspangle@jarthur.Claremont.EDU (Randy Spangler) writes:
>
>I recently was looking for bright LED's to stick on my rollerskates, and the
>only really bright ones I could find were red.  This got me wondering what
...
>Also, what's the easiest way to blink a high-current LED at say 2-10 Hz?
>I've heard there's some way to do it with a 555 timer, but electronics isn't
>my strong point.  Blinking LED's (that have the driver built in) seem to be
>a lot dimmer than non-blinking ones.
An RC circuit should do it:

+  Resistor       LED
-------------------
       \    |    |
       /   ---  \v/ 
       \   ---  --- 
-      /    |    |
-------------------
        Capacitor


To calculate frequency - 
Ohms*farads = 1 time constant (In seconds)
Multiply TC by 5 to find frequency. More I can't remember, but others should
be able to build on this.

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