Thermostat works

Vapor pressure type

The bellows action is applied to the elastic force of the spring , the spring is knob by the control board of the control, the capillary tube on the outlet of an intake air of the air conditioning machine room, the temperature of the return air chamber circulation react. When the room temperature up to the set temperature, the temperature-sensitive agent in the capillaries and bellows gas expansion, the switch contact connected to the bellows elongation and to overcome the force of the spring , the compressor operation, the system refrigerant, until the room temperature further reduced to the set temperature, the temperature sensing package gas contraction, the bellows contracts, together with the spring action, the switch is placed in the OFF position, the motor of the compressor circuit is cut off. This repeated action, so as to achieve the purpose of controlling the room temperature.

Electronic temperature controller

Electronic thermal controller (resistive) is measured using resistance temperature sensing method, commonly used platinum wire, copper, tungsten, and semiconductor (thermistor) temperature resistance, these resistors have their own excellent indeed point. Most home air conditioning sensor based on thermistor. Thermistor type thermostat is made ​​according to the principle of a Wheatstone bridge (left) is a Wheatstone bridge. On the BD ends connected to the power supply E, according to Kirchhoff's law, when the electrical resistance of the bridge R1 × R4 = R2 × R3 is when the potential of the two points of A and C are equal, no current flows between the output terminal A and C the size of the resistance of a thermistor R1 with the rise or fall of the ambient temperature changes, so that the balance of damage, the AC output current. Thus, when constituting the thermostat can easily select the appropriate thermistor to change the temperature adjustment range, and the operating temperature.