Will this circuit work/leak?

Discussion in 'General Electronics Chat' started by stoopkid, Oct 15, 2012.

  1. stoopkid

    Thread Starter Member

    Mar 3, 2011
    136
    1
    I want to power my microconroller with a little tactile button. The chip itself should only draw a few mA, but the LEDs will draw quite a bit more. If I design my circuit like this will I have to worry about it draining my battery while the switch is open? Will the pulldown resistor on the NPN prevent leakage when the uC is powered off? I haven't got resistor values yet but I figure it will be around 10 times of whatever the base resistor ends up being.

    Thanks
     
  2. Bernard

    AAC Fanatic!

    Aug 7, 2008
    4,170
    395
    Best guess-- a μA or 2 leakage.
     
  3. stoopkid

    Thread Starter Member

    Mar 3, 2011
    136
    1
    I think I can live with that.... Thanks
     
  4. paulktreg

    Distinguished Member

    Jun 2, 2008
    611
    120
    Why not switch the +9V to the uC and the LED's then it's not a problem?
     
  5. stoopkid

    Thread Starter Member

    Mar 3, 2011
    136
    1
    Because the tactile buttons are usually only rated for 50 -100mA. All of mine are anyway.
     
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