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LED circuit help for an SPST momentary

Discussion in 'Sim Racing Hardware' started by Alexander Rhodes, Jul 14, 2011.

  1. Alexander Rhodes

    Alexander Rhodes

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    Hey guys, I have a SPST momentary switch with an LED built in.

    I need to know if it is possible to be able to turn the LED on with the first push, and turn it off with the next, without making it a latching switch.

    I have seen multiple diagrams, but they have all been built around latching switches (switches that stay on until pressed again). I can't use such a switch as rFactor and LFS both will not recognize the button press until it returns to off.

    The reason behind this, is that I want to use the LED as a speed limiter indicator. 1 push of the momentary button should activate both the limiter in-game, and the LED, the next push should release the limiter and deactivate the LED.

    The switch has 6 pins:

    1 + 3 +
    5 + 6 LED +/-
    2 + 4 -
     
  2. Jim Cole

    Jim Cole
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    You may have to add some sort of circuit to toggle power when you use the switch. By this I mean that you press and release the switch, the light goes on, press and release again and the light goes off. Will look into it a little and see what is required to make such a circuit.
     
  3. Brian Clancy

    Brian Clancy

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    I could be wrong, but this will not be that easy to achieve in a simple manner at least. Jim is right, it will require a dedicated circuit to make it work.... I will have a think :)
     
  4. Jim Cole

    Jim Cole
    Premium

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    The circuit that is required to make this work is called a "T Flip Flop" I am no electronics person so I can't tell you how to make it, but that is what you need for the light to function the way you want it.
     
  5. Alexander Rhodes

    Alexander Rhodes

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    Will I need an integrated circuit for that?
     
  6. Brian Clancy

    Brian Clancy

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    no promises, but think I have a circuit :) Just need to get the old bread board out and test me theory's out, might be a day or two :p
     
  7. Alexander Rhodes

    Alexander Rhodes

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    Looking forward to your Ideas Brian :D

    I have seen the Todbot vid before, it uses an IC though, I was hoping to avoid that as I'm not going to have much space for one.
     
  8. Brian Clancy

    Brian Clancy

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    Hi Alexander

    Im afraid its gonna have to be a 555 ic job :( I really cant see a better way. On the plus side, it could be made pretty small if you can etch your own boards or know somebody who can ;)
     
  9. Alexander Rhodes

    Alexander Rhodes

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    Well, I guess I'm gonna have to wait on that until I can get hold of one.

    Thanks for your thoughts everyone. I'll go looking for some IC's soon.