Log in

View Full Version : find the wattage/voltage of an LED


Ttop191
12-10-2009, 09:05 PM
ok, so i just pulled an led out of an old light up pen i had lying around and i want to know what it uses for power is there any way short of testing it to find out?

TdotAlero
12-10-2009, 09:17 PM
Those pens usually need one AAA battery to power the LED. Those batteries have the charge of 1.5V

AleroB888
12-10-2009, 09:52 PM
Those pens usually need one AAA battery to power the LED. Those batteries have the charge of 1.5V

Was there a little micro-circuit attached to it, or did the led itself unplug from the housing? Usually the wattage of the resistors used will give you a rough idea.

cherrington17
12-10-2009, 09:54 PM
white leds run 0.20ma and 3.6V

multiply them together for wattage.


its generally safe to assume 4 leds = 1 Watt. unless your talking about luxeon leds, those are different.