Added 2nd LED, now both are too dim

Discussion in 'The Projects Forum' started by Beanster, May 9, 2011.

  1. Beanster

    Thread Starter Member

    May 9, 2011
    I have a "concealed" LED in my car for the radar detector and I recently added a second LED using a splitter supplied by the manufacturer. Now both LED's are too dim. I was thinking of using a relay and powering the relay coil off the LED power wire (and then using the relay output to power the LED's. However, that's just not going to work because the 2.4vDC and extremely low amperage that powers the LED is just not enough to trigger a mechical relay.

    The guys at the local electronics shop (Baynesvilled Electronics) suggested I post this question here.

    Is there any way for an ordinary schmoe to make these two LED's as bright as they should be?
  2. strantor

    AAC Fanatic!

    Oct 3, 2010
    instead of a relay, use a high gain transistor, such as TIP120 Darlington transistor to switch the LEDs. depending on the resistance already present (you mentioned very low amps available) you might need a resistor in series with the base. remember this transistor switches ground, so tie the emitter to ground and tie your LEDs to +12V (or whatever voltage, just make sure you use the appropriate current limiting resistor).
  3. Wendy


    Mar 24, 2008
    Are the LEDs in series? If so that is the problem.

    Each LED must have it's own resistor.

    LED Problems!!