Wednesday, February 16, 2011



The LEDs in this circuit produce a chasing pattern similar the running LEDs display in video shops. All transistors will try to come on at the same time when the power is applied, but some will be faster due to their internal characteristics and some will get a different turn-on current due to the exact value of the 22u electrolytics. The last 22u will delay the voltage-rise to the base of the first transistor and make the circuit start reliably.
The circuit can be extended to any number of odd stages.


  1. I tried but it didn't work... yet . All Leds lights up but they won't start chasing. I checked all resistances , crank up the power supply but i still can't figure what i done wrong.

  2. could you please explain how the circuit is working...