How to adjust the return coefficient of the current relay

There are many factors that affect the return coefficient, such as the finish of the shaft tip, the cleanliness of the bearing, and the position of the static contact. But the more significant impact is the gap between the end of the tongue and the magnetic pole and the position of the tongue. The adjustment methods of the return coefficient are:
1. Change the starting angle and ending angle of the tongue to adjust the starting position of the tongue at the upper left of the relay to limit the screw to change the starting position angle of the tongue. At this time, only the operating current can be changed, and the return current has almost no effect. Therefore, the starting angle of the tongue is changed to adjust the operating current and return coefficient. The greater the distance between the tongue’s initial position and the magnetic pole, the smaller the return coefficient; otherwise, the larger the return coefficient. Adjust the tongue end position limit screw on the upper right of the relay to change the tongue end position angle. At this time, only the return current can be changed without affecting the action current. Therefore, the planting angle of the tongue is changed to adjust the return current and return coefficient. The larger the gap between the position of the tongue and the magnetic pole, the larger the return coefficient; on the contrary, the smaller the return coefficient.
2. Without changing the starting angle and ending angle of the tongue, but changing the bending degree of the two ends of the tongue to change the distance between the tongue and the magnetic pole, the purpose of adjusting the return coefficient can also be achieved. The greater the distance, the greater the return coefficient, and vice versa, the smaller the return coefficient.
3. Properly adjusting the contact force can also change the return coefficient, but it should be noted that the contact force should not be too small.
How to adjust the current of the current relay
The adjustment method of the operating current of the electromagnetic current relay is as follows:
(1) Change the torque of the reaction spring. That is to change the position of the adjusting rod. When the adjusting rod rotates counterclockwise, the spring reaction torque increases, and the I motion increases; on the contrary, the I motion decreases. This method can continuously adjust the operating current of the relay. Read the setting value directly.
(2) The connection method of the two coils of the current relay (series or parallel), the operating current when the coils are connected in parallel is twice the operating current when connected in series.

Popular ic chip you may need:
MR4030
L9113
2SK1762
2SK3568