General elex q

Discussion in 'General Electronics Chat' started by smurfvader, Oct 17, 2010.

  1. smurfvader

    Thread Starter New Member

    Oct 17, 2010
    I have ripped a circuit board out of an old RF (48mHz) remote control car which I'd like to reuse for something else (because of the remote control aspect of it). So far I've figured out that the car's receiver board provides 4.5VDC via 3AA batteries to drive a single forward/reverse DC motor on the car rated at 100mA. What I'd like to do is use this same receiver to instead drive a 12VDC/4A motor. I'd use the same AA battery scheme but add a second 12VDC power source which I already have.

    So...I'm pretty sure I can have this circuit drive a transistor which will switch on the 12VDC and be capable of handling the larger load. However, I'm not sure how to accommodate the fact that the existing circuit reverses polarity depending on whether I'm pressing forward or reverse on the remote...and I need this feature so that my new motor can reverse directions. Any ideas on what I'd have to do to make this work? My initial thought is that I need to design some sort of diode bridge connected to the output of the receiver board to drive separate forward and reverse transistors...but I'm not sure if that would work or if it would be the best approach...or maybe using some sort of relay system would be better?

    Any help or tips would be greatly appreciated!
    Last edited: Oct 17, 2010