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Subject: Re: Drive white leds from bicycle generator
Date: Wed, 20 Nov 2002 13:50:21 -0000
NNTP-Posting-Date: 20 Nov 2002 13:49:57 GMT
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"Thomas C. Sefranek" wrote in message
> GéWé wrote in message
> > How can I drive 20 white leds from a 6V 3W (AC) bicycle generator
> > (dynamo)? Output voltage of the dynamo varies with cycling speed. How
> > can the light output be at maximum at a low cycling speed, and remain
> > constant with increasing speed (= increasing voltage)?
> > Putting as much leds in series as possible is a bit of a problem, due
> > to the output voltage of the dynamo.
> > The circuit has to be simple, since there is not much space in a
> > bicycle headlight.
> > Any ideas?
> Rectify the AC, charge a small battery, regulate the charge,
> then the lights operate even at a stop!
> > Gé
> | __O Thomas C. Sefranek WA1RHP@ARRL.net
> |_-\<,_ Amateur Radio Operator: WA1RHP
> (*)/ (*) Bicycle mobile on 145.41, 448.625 MHz
otherwise you need a buck/boost switching regulator to maintain an efficient
light output over
combining this with the battery mentioned would be good too as it can
provide a near constant charge..
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