Electric wheelchair brakes. The electromagnetic brake is called the eddy current retarder and is a vehicle brake device. When we use some way (pushing the retarder's hand switch or stepping on the brake pedal) to apply DC power to the stator coil of the retarder, a magnetic field is generated in the stator coil, and the magnetic field is in the adjacent core. A loop is formed between the yoke plate, the air gap and the rotor. At this time, if there is relative motion between the rotor and the stator, this motion is equivalent to the conductor cutting the magnetic field lines. According to the principle of electromagnetic induction, an induced current is generated inside the conductor, and the induced current generates another induced magnetic field. There is a force between the existing magnetic fields, and the direction of the force is always the direction that hinders the movement of the conductor. This force is the source of the retarder braking torque.
The electric control system of the eddy current retarder installed on the electric scooter is controlled by a microcomputer. When the vehicle speed reaches a certain speed, the microcomputer control system enters a work standby state, pushes the retarder hand switch, or depresses the brake pedal. The microcomputer control system will gradually increase the eddy current intensity of the retarder according to the number of gears that the hand block opens or the number of air pressure switches that are turned on, so that the vehicle obtains different braking forces.