Need to create a ground

Discussion in 'The Projects Forum' started by Ricks.Radio.Conversions, Apr 12, 2015.

  1. Ricks.Radio.Conversions

    Thread Starter New Member

    Apr 12, 2015
    3
    0
    Hi! I am taking an AM 8-track car radio and converting it to AM/FM. I need to use the track selector switch, it is a momentary switch, and turn it into a latching switch or use a relay to latch and unlatch a ground output.

    Any help would be great! Thank you.
     
  2. MrChips

    Moderator

    Oct 2, 2009
    12,447
    3,363
    You can do it with a logic circuit called a toggle flip-flop.
    Firstly, you need to debounce the momentary switch with a filter circuit and a Schmitt trigger.
    Then you apply the clean signal to the clock input of a T-type flip-flop (created from a J-K flop-flop). From the output of the flip-flop you can drive a transistor or a relay.
     
  3. Denesius

    Member

    Feb 5, 2014
    89
    14
    Don't know how complex you want to get, and whether you know enough to build the circuit recommended by MrChips, buy here's an alternative design. It uses simple circuit & cheap 12v relays:
    http://www.emil.matei.ro/onof2.php
     
  4. Ricks.Radio.Conversions

    Thread Starter New Member

    Apr 12, 2015
    3
    0
    Denesius, thanks a lot! They all look good, but those end results are gating power. I need to gate the ground through, but I think I can manipulate it to work.
     
  5. Ricks.Radio.Conversions

    Thread Starter New Member

    Apr 12, 2015
    3
    0
    Any chance you have a schematic for this?
     
  6. MrChips

    Moderator

    Oct 2, 2009
    12,447
    3,363
    Here is a conceptual circuit, not tested:

    [​IMG]
     
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