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Flashligh Battery Selection
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Re: Flashligh Battery Selection

by Lord Cupcake on Mon May 10, 2010 10:48 pm

Does anyone have any suggestions as how to rapidly flash the LED's in order, giving them the appearance of all being on at the same time, while only having one LED on at a time? This would probably drastically reduce the current draw, thus increasing battery life. I would want to have three strips of five flasing separately, with a maximum of 3 LED's on at a time. This could solve my battery problem. I also want to be able to do it without having to program a microcontroller.
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Re: Flashligh Battery Selection

by oPossum on Tue May 11, 2010 3:18 am

CD4017 or CD4022 + oscillator (4049UB, 74C04, etc..) + transistors to drive LEDs.

http://www.national.com/ds/CD/CD4017BC.pdf
http://www.fairchildsemi.com/an/AN/AN-118.pdf
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Re: Flashligh Battery Selection

by Lord Cupcake on Tue May 11, 2010 7:46 am

I also want to have the LED's conected as a source and sink (switchable) from a 555 timer (for an emergancy flashlight or strobe mode). Will it affect being able to do what I last asked about?
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Please be positive and constructive with your questions and comments.