pnp transistor switch

Discussion in 'General Electronics Chat' started by rubicon99, Apr 25, 2012.

  1. rubicon99

    Thread Starter Member

    Apr 19, 2012
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    0
    So I am making a swithcing mechanism where a micro controller will send a ttl signal to a pnp transistor, the supply will be 12 volts. Pretty much I wanted to know if this can be done and even if I put a load on the output the voltage will not drop from the supply? Or is it better to use an npn.
     
  2. crutschow

    Expert

    Mar 14, 2008
    13,000
    3,229
    Does the load need to be grounded?

    What is the load current?

    A PNP transistor connected to a 12V supply needs a 12V control signal, not TTL.
     
  3. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    7,386
    1,605
    Here's one way to do it (from my current project). CVON is a PIC pin output used to turn on a 28V source.

    [​IMG]
    I use a polyfuse to hopefully keep this from dying when driving a bad circuit as this is a test fixture.
     
    #12 likes this.
  4. panic mode

    Senior Member

    Oct 10, 2011
    1,320
    304
    I see KiCad... ;)
     
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