Electromagnet overcurrent protection circuit

Once the armature of an AC electromagnet is blocked, the magnetic gap increases, the inductance is greatly reduced, and the coil current will reach 6 to
8 times the rated current. If not discovered in time, the electromagnet will be easily burned out. Therefore, in places with harsh operating environments or important occasions, it is necessary
to install protective devices for electromagnets.
    Figure 6-61 is a simple electromagnet overcurrent protection circuit .
    Resistor R can be selected according to the following formula:
    R=UR/I. (n), power PI. In the formula R(W)
, UR - the voltage drop on the resistor R. When the rated operating voltage of the sensitive relay is 12V, UR can be 1.5-2V
    . If the operating voltage is 24V, R can be 3-4V.
    J. ——The rated current when the electromagnet is in the closed state. A.