H-Bridge design question?

Discussion in 'The Projects Forum' started by vaccumdiode, Feb 6, 2009.

  1. vaccumdiode

    Thread Starter New Member

    Feb 6, 2009
    I've Design an h-bridge using four Mosfets. I will control it with an AVR ATmega128 on a "wiring Board" http://www.wiring.org.co/.

    I found a P channel MOSFET that is depletion mode and uses a +5v gate trigger. I put two of those at the top of the H-Bridge and I put two simular N channel mosfets, not depletion mode, at the bottom. I connected the motor across the drains, one of each MOSFET on each side of the motor. I have not built and test it, but I was wondering if the PWM I send to the gate pair if I will have a timing problem? with no PWN sign the two P channel are on and when the PWM goes HIGH one of the P channel MOSFETS should turn off and one of the N channel MOSFETs should turn on allowing current to flow throught the motor and the motor will turn one direction. when I send a PWM sign to the second pair of gates the motor should turn the other direction. I want to use the PWM to regulate the current to the motor as a speed control. I will be using pull up and pull down resistor as needed.

    Should it work?

    Thank you,

  2. beenthere

    Retired Moderator

    Apr 20, 2004
    Post up a schematic, please. That way, we all know what we're talking about.

    Yes, there should be concern about on/off timing to avoid shoot-through.