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View Full Version : Any electronics gurus help me out with this LED setup


silverphoenix
09-13-2011, 11:10 AM
I'm trying to see if I can run 64 3mm Leds off a usb port. Now the LEDs are rated at 3-3.3V @ 20mA, USB port can handle 500mA @ 5v.

Will splitting the circuit into 2 parallel circuits with a 10ohm 1/2watt resistor for each suffice to run each LED without drawing more than 500mA? I know this will drop the current flow through each LED to about 7ish mA but that is fine.

see my expert diagram drawn in Paint below


http://img821.imageshack.us/img821/271/ledsetup.jpg
TJ TRICHEESE
09-13-2011, 11:15 AM
splitting the led's into two sets will make no difference because there still in parrallel
silverphoenix
09-13-2011, 11:40 AM
splitting the led's into two sets will make no difference because there still in parrallel

I only split it so I don't have to use one big beefy resistor.