I want to put together a small lighting system for my parkflier. I bought a pack of LED's from Miniatronics Corp. It comes with 18 LED's and 18 470 Ohm resistors. The recommended voltage is 3 volts for the LED. It says you can use the resistors to prevent the LED from burning out higher voltages. I forgot how to figure out how to use resistors to limit voltage. If the receiver outputs 5 volts, and the LED needs 3 volts how many 470Ohm resistors do I need to limit the voltage to 3 volts. The only equation I remember is I=V/R but that doesn't seem to be enough to figure this out.
- posted
20 years ago