What is a square thing in the back seat cushion of Mavericks go40 electric bicycle?

This is a motorcycle circuit breaker, which is used to connect and disconnect the locomotive from the catenary. Turn off the main circuit breaker when the motorcycle passes through the phase to avoid short circuit.

Circuit breakers can be used to distribute electric energy, occasionally start asynchronous motors, and protect power supply lines and motors. When they have serious faults such as overload, short circuit, undervoltage, etc., the circuit breaker can automatically cut off the circuit, and its function is equivalent to the combination of fuse switch and overheating and underheating relay. Generally, it is not necessary to replace parts after breaking the fault current.

Working principle of circuit breaker:

The working principle of the circuit breaker is that when the circuit is short-circuited, the magnetic field generated by large current overcomes the reaction spring, and the tripping device pulls the operating mechanism to act, and the switch trips instantly. When overloaded, the current becomes larger, the calorific value intensifies, and the bimetal deforms to a certain extent to push the mechanism to act. The greater the current, the shorter the action time. If the circuit breaker is electronic, the transformer is used to collect the magnitude of each phase current and compare it with the set value. When the current is abnormal, the microprocessor sends a signal to make the electronic release drive the operating mechanism to act.