This circuit diagram is based on PWM (Pulse Wide Modulation) to control the speed of a DC motor. PWM is controlled by IC TL494 which has the advantage that can be controlled by using the frequency 100Hz, with the rise and fall time of 10uS. PWM range can be adjusted from 0-100%. You can adjust the speed of a DC motor with a turn potentiometer VR5.
Picture of finshed PWM Motor controller V2.
Picture of finshed PWM Motor controller V1.
The circuit diagram for the motor driver using MOSFET. Especially for this circuit can drive a DC motor with 250W power. We had use 120A/60V MOSFET and one diode MBR3045V. On start up motor draw more than 30 Amps.
On start up motor draw more than 50 Amps after that constant draw is about 30A.
The following is a schematic drawing for PWM Motor speed control V1:
The circuit converts a DC voltage into series of pulses, such that the pulse duration is directly proportion to the value of the DC voltage. The great advantage of such a circuit is that almost no power is lost in the control circuit.
Operation voltage is: 12V to 24 V, minimum current consumption is about 35mA. Efficiency is better than 90% at full load. The PWM Motor speed controlers V2 and V3 has also voltage operation of 12 to 24V and can handle 20A.
PCB is aviable to download for the 20A and 40A DC Motor Controllers, the pcb is real size!
The Controller can be used for DIY Motor Electric Bike, Electric Scooters etc. If you like to increase the power, you should increase the number of MOSFET.
International users, click here.