PWM Motor Speed Controller DIY Learning Kit with NE555

Description

The PWM Motor Speed Controller DIY Learning Kit with NE555 includes the PCB, all the electronic parts, a holder for 3 x AA batteries and a DC motor with a fan blade.

Assembling is straightforward by matching the parts with the clear and easy-to-understand print on the circuit board.

The NE555 chip on this DIY Learning Kit with NE555 is working as a bistable multivibrator with a pulse frequency of about 3-5kHz. Two potentiometers on the Learning Kit with NE555 allow for adjusting the pulse width. RP2 is used to adjust the minimum motor speed and RP2 controls the motor speed between minimum and maximum.

PWM (pulse-width-modulation) is an efficient way of controlling the speed of a DC motor without losing a lot of energy through heat dissipation. It also offers a high motor torque even at low speeds. This circuit is similar to what is used in a battery drill, for example.

The maximum operating voltage of the Learning Kit with NE555 is 25V, but the included motor is not made for that. If you want to use a higher voltage than 6V, you need to replace the motor with a different type. The Darlington output transistor can handle 10A continuously, and its saturation voltage is about 3V at 10A. If you want to connect a large motor that draws 10A, keep in mind a power dissipation of 30W on the Darlington transistor, and provide additional cooling to it.

TIP: Start assembling with the lowest profile parts, which are the resistors laying on the PCB. Proceed with the next taller part. Assemble (solder) the heat sink first, then attach the Darlington transistor to the heat sink using the included screw, before you solder the leads of the transistor to the PCB. If you solder the chip first, and then the heat sink, you will risk bending or even breaking the transistor’s leads.

PCB dimensions: 42 x 56.5mm

You will need 2 additional wires to connect the motor. The kit does not include wires for the motor.