1. Kick-type thermostat: The models of various snap-on thermostats are collectively called KSD, common such as KSD301, KSD302, etc. The thermostat is a new type of bimetal thermostat, mainly used as various electric heaters. When the product has overheat protection, it is usually used in series with the thermal fuse, and the snap-on thermostat is used as the primary protection. The thermal fuse is used as a secondary protection when the sudden-type thermostat fails or fails to cause the electric heating element to overheat, thereby effectively preventing the burning of the electric heating element and the fire accident caused thereby. [1]
Second, the liquid-up type thermostat: when the temperature of the controlled object changes, the physical phenomenon (volume change) and the sense of the thermal expansion and contraction of the substance in the temperature sensing part of the temperature controller (generally liquid) The bellows in which the warm portions are connected together expand or contract. With the principle of leverage, the switch is turned on and off, and the liquid expansion type thermostat with constant temperature control has the characteristics of accurate temperature control, stable and reliable, small temperature difference between start and stop, large temperature control adjustment range and large overload current. The liquid rise type thermostat is mainly used in temperature control occasions such as home appliance industry, electric heating equipment and refrigeration industry.
Third, the pressure type thermostat changes the temperature controller through the closed temperature and capillary of the internal charge temperature working medium, and changes the controlled temperature change into the space pressure or volume change. When the temperature setting value is reached, The elastic element and the fast momentary mechanism automatically close the contacts for automatic temperature control. The utility model is composed of a temperature sensing part, a temperature setting main body part, a micro switch which performs opening and closing, or an automatic damper. Pressure thermostats are suitable for applications such as refrigeration appliances (such as refrigerator freezers) and heaters.
Fourth, the electronic thermostat, electronic temperature controller (resistive type) is measured by the method of resistance temperature sensing, generally using platinum wire, copper wire, tungsten wire and thermistor as temperature measuring resistors, these resistors Each has its own advantages. Most household air conditioners use thermistor type.
Steam type
Working principle: vapor pressure type
The action of the bellows acts on the spring. The spring force of the spring is controlled by the knob on the control panel. The capillary is placed at the air inlet of the air in the air conditioner to react to the temperature of the indoor return air. When the room temperature rises to the set temperature, the temperature sensor gas in the capillary tube and the bellows expands, the bellows is extended and the switch contact is turned on against the spring force of the spring. At this time, the compressor is running, the system is cooled, and the temperature is cooled. When it is lowered to the set temperature, the temperature-inducing gas shrinks, the bellows shrinks together with the spring, and the switch is placed in the off position to cut off the motor circuit of the compressor. This is repeated to achieve the purpose of controlling the temperature of the room.