DC Motor Control

Other Hardware General Electronics
3

Thanks for the reply.

  1. I've found this transistor, 10A and more than enough room for my required voltage. http://uk.rs-online.com/web/p/general-purpose-transistor/5449371/
    Is this right? Good price?

  2. Been following this: http://www.electronics-tutorials.ws/transistor/tran_2.html
    According to the transistors docs the current gain is 5 at 10A and 20 at 4A therefore:

Ic = 10A
Ie = 10 * 5 = 50A ?
Ib = 50 - 10 = 40A ?

  1. Thirdly what resistor will I need, as in, how many ohms? I understand the Arduino has a 40mA max but I should probably not go that high? Not sure on how to calculate current/resistance when using transistors. I think I need a 500 ohm resistor based on my calculations, but I don't know if transistors do something fancy.

  2. The Arduino pin at 5V right?

  3. Also, diodes. No idea on this one as all circuit diagrams just say "put a diode here". I presume they have max ratings and such. Will it also need to be 10A and > 7.2V? This is to stop current induction when the power is cut to the motor right?

Again, new to transistors so help appreciated :slight_smile: