H-Bridge for use with PIC

Discussion in 'General Electronics Chat' started by Mad Professor, Jan 28, 2011.

  1. Mad Professor

    Thread Starter Active Member

    Apr 15, 2009
    Good day all.

    I am looking for advice regarding using a H-Bridge with a PIC microcontroller.

    I have spent alot of time looking on this forum and on google, trying to find the answers, but not having a grate deal of luck, and just seem to be going round and round.

    I can see that the H-Bridge topic does show up alot on the forum, but could not find what I was looking for.

    I am trying to control a 12v DC brushed motor from a PIC microcontroller, the motor pulls a max of 5amps @ 12volts, when under max load.

    I need CW, CCW control, I don't need motor braking, just On/Off so no pwm needed.

    So far this is the schematic I have come up with.
    Can you please advice.

    Thanks for your time.

    Best Regards.
    Last edited: Jan 28, 2011
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    With no speed control or braking, just use a DPDT relay with 10 amp contacts to switch voltage polarity to the motor. On Darlington to run the relay, one to control current through it.
  3. SgtWookie


    Jul 17, 2007
    Well, a DPDT would give forward and reverse, but no OFF!

    One could use two SPDT automotive relays for a simple and inexpensive H bridge.
    The motor's terminals would be connected to the relay common terminals.
    Both NC terminals get connected to ground (12v return)
    Both NO terminals get connected to +12v.
  4. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
    Power MOSFET to Logic H-Bridge

    That is one option, essentially using the BJTs to drive the MOSFETs, which can then handle a great deal of current without much dissipation. it uses both P and N Channel Logic Level MOSFETs, in addition to 2 PNP and 2 NPN small signal BJTs.

    It's a bit complicated, but a 5A motor isn't a common request.