Control methods are usually classified in to kinds, is by by cooling object changes in temperature to control, use more steam pressure type temperature controller, another by cooling object variations in temperature to control, use more electronic temperature controller. The thermostat is divided in to:
Mechanical divided in to: steam pressure type thermostat, liquid expansion type thermostat, gas adsorption thermostat, metal expansion type thermostat.
Including steam pressure type thermostat is divided again: inflatable, liquid gas mixed & filling liquid type. Relatives expenses air conditioning mechanical with this sort of thermostat primarily. Electronic divided in to: resistive thermostat & thermocouple type thermostat.
The circuit parts fundamentally has: temperature controller, thermal protectors, master switch, walking capacitor, fan motor walking capacitor. Temperature controller role only control of compressor starts & stops. http://www.jyins.com/temperature--controller-series.html