DC Motor Controller using Relay and MOSFET – Arduino Interface

The project presented here is a low-cost solution to control high power brushed DC motor speed and direction. Traditional DC motor controllers are based on solid-state circuitry known as H-Bridge. Here we have made an H-bridge configuration using high current 2 x relays which can handle high voltage as well as high current. Additional MOSFETs are used to control the speed of motor. These MOSFETs can be removed in case of only direction control required, short the Drain and source pin of MOSFETs. The project requires 3 control input signals, all inputs are optically isolated to prevent noise and high voltage going in to logic circuitry. A large-size heatsink is a must on MOSFET.

The project requires 3 input signals, 2 x TTL 3V to 5V for direction control and one PWM 0 to 100% Duty Cycle for speed control. Operating supply is 12V DC for logic circuit and relay, Motor supply 12V to 90V DC, Load up to 20A.

Features

• Power Supply for Relay and MOSFET 12V DC @ 100mA
• Power Supply Motor 12V to 90V DC
• Motor Load 20A (Maximum 30A)
• All Inputs are Optically isolated
• 2 x Inputs for Direction Control and Brake
• One PWM Signal to Control the speed of Motor 0 to 100 % Duty Cycle
• PWM Frequency 300Hz to 20 Khz
• 2 x LEDs for direction indication
• PCB dimensions: 75.41 x 74.30 mm