what is the working function of latching relay?
The so-called self locking circuit, as the name implies, which is able to lock the circuit and keep the circuit on. In the usual circuit, the switch is pressed, the circuit is energized, the switch is loosened, and the circuit is disconnected. In particular, once the switch is pressed, it can automatically maintain the continuous power until it is pressed by other switches to make the circuit breakable; such a circuit is called a self locking circuit.
How does the latching relay to work? The latching relay can be connected in series with the relay's main contacts (relay coils). At the same time, a spare auxiliary contact (normally open contact) of the relay is connected in parallel with the switch (and connected to the main contact). In this way, when the latching relay is pressed, the sub-contact (normally open contact) pulls in and the circuit is energized; after the switch is released, the sub-contact has been drawn and supplied to the coil of the relay's main contact, and the coil is reversed. Keep the auxiliary contacts closed. The line is then routed out of the relay output and the circuit can maintain continuous power.