problem with up counter using jk flip flop

Discussion in 'The Projects Forum' started by siatong, Nov 9, 2008.

  1. siatong

    Thread Starter New Member

    Oct 20, 2008
    I am having a hard time making an up counter using jk flip flop. I have already made a circuit in electronic workbench and the output was right, the leds lights correctly according to its clock pulse but when I apply it, I buy CD4027BE dual jk flip flop ,a 555 timer, resistors,capacitors and leds.I have made the circuit in breadboard but unfortunately the output was not right, I have tried many times but still it was not right. Pls help if anyone knows how to troubleshoot this type of problem..
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    You will have to post your circuit before we can help you. Just at a guess, if you have left any of the inputs unconnected, that may be your problem. Another may be trying to drive LED's with a CMOS chip - they are voltage output and LED's need more current than they can supply (that is why there are special chips to drive LED displays).