I want to buy 10 LEDs and put them all together in a circuit. Each LED needs 1.7VOLTS and 20mA. I have 10, so that would be 17 volts. I want to power it off 2 9Volts, aka 18VOLTS. So, I went (18-17)/.02 = 50. So I need a 50-ohm resister, right? Where would I buy one? I found a 50OHM, but it is rated for 5WATTs. Is that OK? Also, would a 51OHM work? If so, should I get 1/4 or 1/2 watt?
THANKS!
THANKS!