Any help would be much appreciated

Discussion in 'General Electronics Chat' started by Brinks, Apr 23, 2006.

  1. Brinks

    Thread Starter New Member

    Apr 23, 2006
    Am looking for a working circuit for a one-shot switch (12V DC), a single pulse to operate two separate coils.
    Coils to operate alternatively from single momentary switch, but each when on to be active only momentarily.

    Any help would be much appreciated
  2. Papabravo


    Feb 24, 2006
    Let me see if I understand what you want. You want one pushbutton switch to alternately activate either coil1 or coil2 for some period of time longer than the the depression of the pushbutton and shorter than some predetermined interval. The memory of the last coile energized needs to be maintained as long as the power is on. Do I have this correct.

    Is this a PLC problem, a ladder logic problem, or can I pretty much use any reasonable piece of electronics to do the job?
  3. Gadget

    Distinguished Member

    Jan 10, 2006
    The momentary switch feeds the Clock input of a JK flip flop wired in toggle mode (J & K inputs held high) with the 2 outputs gated with AND gates via the original momentary switch. Buffer the outputs from the 2 AND gates with a transistor, and put the coils (with back EMF protection diodes in parallel) between the Collector and supply.
    Simple, but should do the trick.
    Circuit diagrams cost extra.