DC motor speed control.

Discussion in 'The Projects Forum' started by lam58, Feb 13, 2014.

  1. lam58

    Thread Starter Member

    Jan 3, 2014
    I'm designing a dc automatic toy car that drives and regulates itself around a track. It follows a induced wire around a table about 20m long and using inductive pick ups it will regulate the speed and tell the car to turn corners etc. My group have decided the easiest way to design this is using an adruino board powered by a 5v supply. The problem we have though is the outputs from the arduino will not be enough to power to two rear motors. As a result we were thinking of attaching the arduino outputs to a common emitter followers transistor and use say a 5v supply as the vcc input and using the arduino outputs to "switch on" the transistors. I was just wondering if this sounds like a good idea, and are there any hints or tips you could give when designing this circuit.
  2. Alec_t

    AAC Fanatic!

    Sep 17, 2013
    'Logic-level' N-channel MOSFETS, used as low-side switches, would be a better choice than emitter-followers.
  3. AfdhalAtiffTan

    Senior Member

    Nov 20, 2010
    To reduce wasted heat, I would suggest to use common emitter rather than emitter follower, i.e. saturating the transistor.