What I'm looking to do it switch on/off an LED. What I have is a 3v+ signal that I need to trigger a transistor, which in turn will illuminate an LED. The 3v+ signal won't support the current for an LED, so it has to trigger the transistor. My plan was to use a NPN transistor, and feed an LED 12 volt through a 470k resistor. What I need to know is if there is anything more to it than that, and what transistor to use. The LED is 3v 20ma. I see schematics on the 'net for this, but they're all different, some having several resistors. What I 'think' I need is a transistor, an LED, and a 470k resistor. Do I need another resistor for the base if the signal is 3 volts? Anything else I need? Thanks, Greg.