Bill Marsden's 'from 4 20' circuit x2

Discussion in 'The Projects Forum' started by Fenris, Aug 28, 2009.

  1. Fenris

    Thread Starter Active Member

    Oct 21, 2007
    Hi guys

    Right then heres my next project. Again inspired by Bill's E-book of all things LED! Basically 4 555 timers drive 20 LED's in a varied and haphazard fashion. But with my usual flair for going over the top I am doing a 'from 4 40'.

    It's a bit of a cheat though. I'm using 4 556 chips so it's really an 'from 8 40' circuit :D

    I have all the parts especially the 40 3mm Blue LED's care of Bill (Cheers!)
    In Bills original schematic the timers are fixed at different speeds. With this design I intend to make the speeds variable of some or all of the timers.

    Today I have done the toner transfer of the patterns I devised for the 2 part circuit. The main board (smallest) has the 556's on it and is around 2" square and the larger board for the LED's is 3"square. 10 Wires will connect the 2 boards.

    Heres a pic of the PCB's waiting for etching.