What is the speed relay working principle?
Speed relay according to the principle of electromagnetic induction for the detection of speed, such as used in three-phase AC asynchronous motor reverse braking speed zero, the automatic removal of reverse phase sequence power supply.
Speed relay mainly by the rotor, ring and contact three parts.
The speed relay works as follows:
The speed relay rotor shaft is connected to the axis of the controlled motor and the stator is mounted on the rotor. When the motor rotates, the speed relay rotor rotates, the stator short-circuit conductor will cut the magnetic field, resulting in induced electromotive force, resulting in current. This current generates torque with the rotating rotor magnetic field, and the stator starts to rotate. When the turn to a certain angle, mounted on the stator shaft pendulum to promote the reed action, so that normally closed contact breaking, normally open contact closed. When the motor speed is below a certain value, the torque generated by the stator is reduced and the contact is reset under the action of the spring.
Commonly used speed relay with YJ1 type and JFZ0 type. Usually the speed of the relay action speed of 120r / min, reset speed of 100r / min.
Turn left to turn right
Speed relay, as the name suggests, is when the machine running to a certain speed, you can make the relay action. Commonly used speed relay there are two, one is mechanical, directly to the machine or motor speed to take to promote the contact of the clutch. The JMP speed relay, which can reflect the level of the machine or motor speed out to promote the contact of the clutch, and the Hall sensor is similar.
