need help with a power transistor

Discussion in 'General Electronics Chat' started by dwoodard27, Aug 7, 2010.

  1. dwoodard27

    Thread Starter New Member

    Aug 7, 2010
    How do you step up a power transistor that will be coming from a nor gate which is in line to a relay. I need to step up the voltage from 5 to 12 volts in order for the relay to trip. Nominal current of the relay is 30mA.
  2. R!f@@

    AAC Fanatic!

    Apr 2, 2009
    connect gate via 1k to transistor base of BC639, a 4.7K from base to GND, Emitter to GND, collector to one side of relay coil and apply 12V to the other end of coil. Next connect a 1N4007 Diode across the relay coil, cathode of D going to +12V side of coil
  3. Wendy


    Mar 24, 2008
    This is not the forum to ask this kind of question, it should have gone into the electronic chat forum.