RGB Controller Help

Discussion in 'The Projects Forum' started by RodneyB, May 6, 2013.

  1. RodneyB

    Thread Starter Active Member

    Apr 28, 2012
    I Have attached a diagram of an RGB controller I am trying to build.
    When I apply power the green and Blue LED in the tri colour LED seem to glow but nothing happens.
    I am cncerned about my transistor switching on the LED from the CD4029 orginally the circuit required a common Cathode LED but I could not find any so adjusted the circuit as I thought correct.
    I have found the 4029 gets warm not HOT and nothing happens.
    are the transistors switch the LED's correct ?
    How can I build a simple circuit to switch a single led, from the 4029 this would enable me to check if the IC is faulty.
    Many thanks
  2. JohnInTX


    Jun 26, 2012
    The B-C-D-Cin inputs are floating. They should be strapped low.

    You might be violating timing on the preset enable since you are depending on internal delays to generate the timings.

    Presumably the 555 is powered from 12V as well to generate proper clock levels.

    Your base resistors could be a bit smaller for more LED drive. Other than that, the LED circuit is OK.

    Try running it just counting without the feedback (isolate and strap PE low) When all LEDs follow a binary pattern, add the feedback and troubleshoot from there.
  3. wayneh


    Sep 9, 2010
    Bypass caps on the power supplies to the 555 and the 4029 would be wise.
  4. JohnInTX


    Jun 26, 2012
    I always assume that's a given but you're right to point it out.