Implementation Method Of Electronic Brake for Brushless DC Motor

Author : Mark Markus | Published On : 28 Mar 2024

1. Braking method

There are two main braking methods for brushless DC motors: mechanical braking and electronic braking.

1. 1 Mechanical brake

Mechanical brake is to add a braking device to the mechanical part of the motor to stop the motor from rotating through a chuck or friction plate. The advantages of mechanical brakes are simple structure and adjustable braking force, but the disadvantage is that it increases the wear and noise of the motor life.

1.2 Electronic brake

Electronic braking is a way to achieve braking through electronic control equipment. Compared with mechanical brakes, it not only has stable braking torque, but also does not cause additional wear and noise to the motor.

2. Electronic brake control circuit design

The electronic brake control circuit can control the motor speed through PWM, and then input the processed brake signal to the brake port of the motor controller. The braking signal is generally implemented by load inversion. Specific steps are as follows:

2.1 Connect the A and B phase lines of the motor to the drive port of the motor control chip;

2.2 Connect the PWM output of the motor control chip to the control chip of the motor controller;

2.3 Connect a forced braking switch to the brake input port of the motor control chip. One port of the switch should be connected to the positive pole of the power supply, and the other port should be connected to the brake port of the control chip;

2.4 Connect the negative terminal of the battery to the GND of the motor control chip.

3. Electronic brake implementation steps

The steps to implement electronic braking are as follows:

3.1 Adjust the duty cycle of the PWM waveform through programming to slow down the motor;

3.2 Set the brake switch to the brake position so that the brake input port of the motor control chip is connected to the positive pole of the power supply;

3.3 The motor control chip adjusts the output, changes the magnetic pole state of the motor, and stops the motor.

4. Precautions

In practical applications, the following points need to be noted:

4.1 The power supply of the braking circuit must be stable. Power supply fluctuations will lead to poor braking effect;

4.2 The brake switch needs to have good contact performance to avoid poor contact or short circuit. During use, maintenance and cleaning are also required to ensure stable performance of the brake switch;

4.3 Set the braking parameters correctly to avoid braking too slowly, causing the motor to slide or burn out, and not braking too quickly, causing damage to mechanical parts.

In short, electronic braking can greatly improve the precision control and safety of brushless DC motors, and requires correct application and maintenance to achieve maximum effect.