Nowadays, the use of temperature controller is more and more widely used, such as refrigerators, air conditioning, boiler and so on. The temperature controllers used in daily use are mainly divided into mechanical and electronic. The tradition is mostly mechanical controller, but the mechanical type is more easily damaged and imprecise. With the rapid development of science and technology, electronic control circuits have been widely applied in daily life, because it is more convenient and precise, and has a profound impact on people's lives. But do you know what the working principle of the thermostat is? Do you want to see what kind of working principle can make it so magical? Let's have a look.

Temperature controller (Thermostat), according to the temperature change of the working environment, physical deformation occurs in the internal switch, resulting in some special effects, produce conduction or disconnect a series of action of automatic control components, or electronic components at different temperatures, the working state of different principle to provide circuit temperature data for circuit temperature data acquisition. The temperature controller is to operate the temperature of the controlled object to the required temperature, and this process is the temperature control.

Detailed explanation of the working principle of the thermostat

The working principle of the thermostat

The temperature controller can be divided into:

1., the mechanical temperature controller is divided into steam pressure type temperature controller, liquid expansion temperature controller, gas adsorption temperature controller and metal expansion type temperature controller.

The steam pressure temperature controller is also divided into two types: aeration type, liquid gas mixture type and liquid filling type. The temperature controller of household air conditioning is mainly based on this kind of temperature controller.

2. the electronic temperature controller is divided into: the resistance temperature controller and the thermocouple temperature controller.

Working principle of temperature controller:

1. steam pressure temperature controller

The action of bellows on temperature controller acts on the spring. The spring force is controlled by the knob on the control board. The capillary is placed in the air inlet of the air conditioner, and it responds to the temperature of the indoor circulating air.  When the temperature rises to the setting temperature, capillary and bellows temperature agent gas expansion, the bellows elongation and overcome the elastic force of the spring contact switch, the operation of the compressor, refrigeration system, and then decreased to room temperature until the set temperature, temperature of gas contraction, contraction and bellows spring with the action of the switch in the off position, the motor compressor cut-off circuit. In this way, the temperature of the room is controlled by repeated action.

2. electronic temperature controller

The electronic temperature controller (resistance type) is measured by the method of resistance temperature sensing. Generally, white gold wire, copper wire, tungsten wire and semiconductor (thermistor) are used as temperature measuring resistors, each of which has its own merits. Most of the sensors in the home air conditioning temperature controller are thermistors.

The temperature controller of the refrigerator is mainly composed of a feedback circuit and a comparator. When the temperature inside the box is set, the temperature in the box will be measured by thermistor. When the temperature is higher than the set temperature, it will increase the power and strengthen the refrigeration, otherwise it will decrease. If it works all the time, it will set the temperature.