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Topic: LED cube shift register power (Read 1 time) previous topic - next topic

ematson5897


Grumpy_Mike

It depends then on how many LEDs are going to be on at any one time and how you wire them.

Docedison

An Led requires a CONSTANT CURRENT for proper operation, regardless of Duty Cycle the current must be limited. Above the turn-on point (voltage ~2V for red and ~3V for green/blue) the led is a short circuit and current MUST be limited. Short Duty cycles apparently work... They DON"T, instead you wind up spiking the 5V source every time you enable a non current limited LED. If you limit the current you don't NEED to shorten the Duty Cycle. Don't forget to BY-PASS, BY-PASS, BY-PASS. Cheap insurance and often times the answer to what looks and acts like a bad sketch. Nice thing about a Bread board is that you can just PLUG them in... IMO

Doc
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