12V input switch output to µC TIP126?

Discussion in 'General Electronics Chat' started by ericscott, Apr 27, 2012.

  1. ericscott

    Thread Starter New Member

    Apr 27, 2012
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    I'm using a 12V switch, where a light bulb need the 12V on the switch, and want to output a +5V high to µC pin to controll other outputs, but can I use a TIP120 or TIP126 as I have them. I'm not clear how to connect?
     
  2. BillB3857

    Senior Member

    Feb 28, 2009
    2,400
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    You could use a pot. Switched 12 volts at one end, ground at the other and adjust for 5 volts on wiper.
     
  3. ericscott

    Thread Starter New Member

    Apr 27, 2012
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    Wouldn't the pot get really hot? Well I will give it a shot.
     
  4. BillB3857

    Senior Member

    Feb 28, 2009
    2,400
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    That would depend upon the value of the pot. As a couple of examples, if it were a 1K pot, it would draw 12ma current. 12ma X 12v= 0.144 watt. A 500 ohm pot, on the other hand would draw 24ma X 12V=0.288 watt. I would use a 1K or larger.
     
  5. ericscott

    Thread Starter New Member

    Apr 27, 2012
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    Could I also use a Voltage regulator to switch +12V to +5V, because its just the lamp that requires +12V, the switch part should be +5V?
     
  6. ericscott

    Thread Starter New Member

    Apr 27, 2012
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    0
    That worked,
    Thanks!
    eric
     
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