driving multiple bipolar transistors

Discussion in 'The Projects Forum' started by brodonh1, Apr 21, 2015.

  1. brodonh1

    Thread Starter Member

    Sep 15, 2008
    12
    0
    Hi All,
    Need some help.
    I built a motor that has coils and one winding is a trigger winding.
    The motor runs great with the trigger winding.
    However, I want to switch the transistors to pulse the coils with IR diodes.
    I have another motor that I'm switching with IR diodes but it has mosfets and I can connect the mosfets right from the diodes cct which is powered by a 12v battery. It runs fine.

    I need to switch up to to 25 MJL21194's.
    At present attempting to switch 10.
    What do I need for the MJL's?
    I tried a darlington pair out of the diode cct to no avail.
    I tried adding a 9v batt with resistance to no avail.

    I'm probably missing a basic matter in this so would appreciate some help.

    Thanks for being here,
    brodon1
     
  2. einspace

    New Member

    May 9, 2011
    1
    0
    So you want to drive a Bedini motor with 25 coils with just one optical switch? I think you will need a transistor driver like the TC4421. And maybe an optocoupler to protect the chip.
     
  3. brodonh1

    Thread Starter Member

    Sep 15, 2008
    12
    0
    Mr Einspace,
    Happy to hear from you again.
    I've built many large Bedini SSG machines but never learned what exactly was going to the MJL21194's.
    I'll check out the TC4421.
    Thanks,
    bro d
     
  4. brodonh1

    Thread Starter Member

    Sep 15, 2008
    12
    0
    einspace,
    Can I drive bjt's with this mosfet driver?
    Thanks,
    bro d
     
  5. brodonh1

    Thread Starter Member

    Sep 15, 2008
    12
    0
    This one works.
    T1 can be many npn's.
    bro d
     
  6. brodonh1

    Thread Starter Member

    Sep 15, 2008
    12
    0
    Emitter to ground should be removed from T2.
    Been running at 4000 rpm.
    bro d
     
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