Impulse relay turns on with an electrical impulse at the control input and turns off again with another impulse.

Here is the circuit of an Arduino-based Panic Alarm! The wiring is very simple so that even a novice can construct ... An additional Electro-Magnetic Relay (EMR) is also attached to the interface ...

It is simple, hold the flame ... low-trigger, 5V relay module. This relay module also has two photocouplers to provide galvanic-isolation between its input and output circuits. Basic circuit diagram ...