1. Temperature controller and temperature limiter Temperature controller and temperature limiter are temperature control elements that function during normal operation of the appliance. The difference: -- The temperature controller limits the controlled temperature within a range by disconnecting or connecting the controlled circuit. The working characteristics of the thermostat can be popularly likened to "two-way work". For example, the temperature control element in the electric water heater is the thermostat. The thermostat is adjustable. -- The temperature limiter limits the controlled temperature below or above a certain temperature point by disconnecting or connecting the controlled circuit. The working characteristics of the temperature limiter can be popularly likened to "one-way work". For example, the temperature control element in an electric kettle is a temperature limiter. The temperature limiter is not adjustable. 2, the thermal circuit breaker definition: the thermal circuit breaker is a temperature control element that acts during abnormal working. 1) In the home appliance machine and its electrical accessories industry, temperature control components are often commonly known as or collectively referred to as temperature controllers. However, when it comes to the concept of this standard, it is necessary to strictly distinguish the temperature control element operating under normal operating conditions - thermostat - from the temperature control element operating under abnormal operating conditions - thermal circuit breaker. 2) Similarly, the thermal circuit breaker and thermostat that can be seen in the industry are not necessarily completely separate in terms of appellation, appearance shape, nominal parameters, etc., and need not be completely separate. A temperature control element has a specific meaning in the definition only when it is applied to the appliance and its specific control purpose is specified. 3) The thermal circuit breaker made of PTC elements limits the temperature by reducing the current. 4) The thermal circuit breaker has self-reset and non-self-reset points. The air switch needs to be manually reset after operation. After the hot melt action needs to be replaced with a new part reset. 1) The type of protection device has at least - the protection device for temperature anomalies, such as thermal circuit breakers. -- Protection devices against abnormal current, such as current fuses. - Protective devices against mechanical hazards, such as pressure relief devices, interlocking devices for food processing equipment, etc. A weak link in an appliance or in an electrical circuit. -- Other dangerous protective devices, such as microwave oven door interlocking devices. 2) The protective device here does not include some protective structures, such as insulation structures, waterproof structures, etc.