Voltage zero-crossing protection technology, for the protection of the relay in the product.
The mechanism of protection realization is: the power supply to the relay coil is controlled by the single-chip microcomputer, thereby controlling the closing of the relay contacts. At the same time, the trigger point happens to be the zero voltage position of the AC sine wave. The relay contacts are closed near the zero voltage position, which can minimize the arcing of the contacts, thereby protecting the relay from the impact of large currents.
Blue line- the sine wave of alternating current
Yellow line -the trigger point for the relay contact to close
1-1 The trigger point is in the zero-voltage region
1-2 Trigger point deviates from zero voltage
1-1 Near the trigger point and the zero voltage position, when the contact is closed, the physical loss of the relay’s instantaneous excessive current can be avoided.
1-2 When the contact is closed, there is an arc from the zero voltage, then when the contact is closed, there is no relay protection.