DC Motors

DC Motors

DC Motors at Aalto Mechatronics #

Standard DC Motors #

DC motor

  • Usually just 2 wires
  • You can control the speed and direction. The direction depends on which terminal of the motor you connect to + and – of your power supply
  • Use a transistor or an H-Bridge circuit to control
  • On the Arduino you can just use digitalWrite() and analogWrite()
  • A standard brushed DC motor usually has a very high rpm, but very low torque. Some sort of gear system is usually required for real-life applications.

TT Motor #

TT motor

  • 3–6V DC
  • About 250 rpm
  • Cheap
  • Plastic gears
  • You have these in your Physical Computing kit

12V DC Motors #

12V DC motor

  • Stronger
  • Different gear ratios (slower rpm means higher torque)
  • We have at least 50 rpm and 1 rpm motors

How to control DC Motors? #

Powering directly | Switch | Relay (ON/OFF) #

Transistors (ON/OFF and Speed) #

If you want to take one step further in the level of control you can move on to transistors. Transistors can be controlled with a PWM signal to control the speed of a motor. See the Transistor page for more specific details on transistors.

TIP120 #

Here is an example with the

N-Channel Mosfet #

Mosfets are more efficient than standard BJT or Darlington transistors which means that they don’t get as hot and don’t waste as much energy. They need to be connected in a slightly different way than the TIP120 transistor.

H-Bridge (ON/OFF, Speed, Direction) #

Examples #