Vapor pressure type

The action of bellows acts on the spring. The spring's elastic force is controlled by the knob on the control board. The capillary is placed at the air intake outlet of the air conditioner indoor, which reacts to the temperature of the indoor circulating return air. When the room temperature rises to the set temperature, the temperature-sensitive agent gas in the capillary and bellows expands to make the bellows elongate and overcome the spring elasticity to connect the switch contacts. At this time, the compressor runs, the system refrigerates, and when the room temperature falls to the set temperature, the temperature-sensitive package gas shrinks, the bellows shrink and the spring act together, and the switch is placed in the disconnected position to make the compressor electrically operated. The motor circuit is cut off. In order to achieve the goal of controlling the room temperature, the action is repeated.

Electronic Temperature Controller

Theelectronic temperature controller (resistance type) is measured by the method of resistance inductance temperature. Generally, platinum wire, copper wire, tungsten wire and semiconductor (thermistor, etc.) are used as temperature measuring resistors. These resistors have their own advantages and disadvantages. The sensor of household air conditioning is mostly thermistor type.

The thermistor thermostat is based on the Whiston Bridge Principle (left) is the Whiston Bridge. According to Kirchhoff's law, when the resistance of the bridge R1*R4=R2*R3, the potential of A and C is equal. There is no current flowing between the output A and C. The resistance of the thermistor R1 changes with the rise or fall of the ambient temperature, which destroys the balance and the output current between AC. Therefore, when a thermostat is constructed, it is easy to change the temperature range and working temperature by choosing an appropriate thermistor.

Metal expansion thermostat:

According to the principle of thermal expansion and contraction. Thermal expansion and contraction are the common characteristics of objects, but different objects have different degrees of thermal expansion and contraction. The two sides of the double gold sheet are conductors of different substances. At different temperatures, the double gold sheet bends due to different expansion and contraction degrees, and meets the set contacts or switches, so that the set circuit (protection) starts to work.

In the field of overheat protection:

1. Various types of motors/micromotors 2, induction cooker 3, ballast 4, electric heating belt 5, health care equipment

6. Electric heating apparatus 7, water pump 8, exhaust fan 9, vacuum cleaner 10, electric tool 11 battery 12, various electric heating products, etc.

According to the nature of the action, it can be divided into open action and closed action.