What Is a Solenoid Driver?

If the magnetic field moves relative to the conductor, an induced current will be generated in the conductor. The induced current causes the conductor to be subjected to the ampere force, which moves the conductor. This effect is electromagnetic driving.

Electromagnetic drive

When the magnetic field moves the conductors together, this effect is called "electromagnetic drive" effect. when

Electromagnetic driving can be used to make electric meters that measure rotational speed. This type of tachometer is often called a magnetic tachometer. In order to ensure that the generated alternating current frequency f = 50 seconds-1 in the generator, the speed of the rotor must be controlled. In other cases, in order to give full play to the efficiency of the machine and use it properly, it is often necessary to measure its speed and then further control and adjust it.

When measuring the speed with a magnetic tachometer, the shaft of the machine under test is connected to the shaft of a permanent magnet in the tachometer through a connector and a transmission mechanism. The permanent magnet is generally made of a piece of magnetic steel filled with four poles. A rotating magnetic field is formed. Above the permanent magnet is a metal disc called an induction plate. There is a small air gap between the induction piece and the permanent magnet, and the two are not in contact with each other.

When the permanent magnet rotates with the rotating shaft of the machine, an eddy current will be generated on the induction sheet. This eddy current will in turn be subjected to the force of the rotating magnetic field, and as a result, the induction plate will be driven to move in the direction of rotation of the permanent magnet. The rotation of the induction piece will drive the spring connected to the rotation axis of the induction piece to tighten it, thereby generating elastic recovery torque. Finally, when the induction plate rotates through a certain angle and the torque generated by the electromagnetic drive happens to cancel out with the elastically restored torque, a temporary equilibrium state is reached. The faster the rotating speed of the permanent magnet driven by the machine, the greater the torque generated by the electromagnetic driving action of the induction piece, and therefore the larger the deflection angle of the pointer. In this way, the speed of the machine can be displayed by the deflection angle of the pointer.