how do you figure out what resistor to use for a 500k pot and a white 2.1v / 30mA LED with a 9V power supply?



The pot (short for potentiometer) IS your resistor, albeit a variable one. Though if you do plan on using a 9v supply you might want to supplement it with another resistor. Google for an led calculator and that should help.
surlistyc (author)  The Ideanator6 years ago
I know how to calculate what resistance I would need for an LED, but I don't know if it would be any different with the pot in the circuit.
my pot was from an old guitar, if that helps with anything.
Ok, I think I can word this right,
How can I make my pot go from 0 to 1000 instead of 0 to 500k ohm resistance with resistors, and what is the equation/s? or what is the way to figure it out?