Thermal switch is a kind of through the temperature control circuit switch that open or close, mainly used in some of the need to control temperature in life appliances or some higher science and technology field. The average thermal expansion switch involves two pieces of sheet metal is heated, then specifically, how thermal switch operation, follow in the footsteps of small make up take a look at the working principle of thermal switch.

Thermal switch principle

Principle of double metal plate thermal switch

Mentioned in the introduction, the metal plate thermal switch inside with two pieces of special pieces of metal, it looks same these two pieces of sheet metal, but has different physical properties. They have different thermal expansion effect in every layer, namely the thermal expansion coefficient. Under the influence of temperature, two pieces of sheet metal would have different deformation, the deformation is a result of their overall toward one side bending, the effect of the curvature and deformation control closing or opening of the circuit, thus the effect of the temperature control switch.

Thermal switch principle

Principle of wax thermal switch

In wax thermal switch has a wax pill, the wax pill can be changed with the temperature, heat bilges cold shrink, wax pill above even with a push rod, push rod connected to a lever with a tension spring, they together with the up and down movement of the push rod control contact on contact, so as to control circuit connected or disconnected. This type of thermal switch principle is simple, currently on the market is a kind of commonly used thermal switch.

Thermal switch principle

Two kinds of thermal switch disadvantage

Wax thermal switch, need to use the temperature of the cooling fluid to restore wax pill, and after a long time, the use of diaphragm deformation happens, wax pill will also have some penetration, these changes will usually cause coolant liquid temperature becomes higher, on the other hand, also will make the contact cannot be connected or connecting point of problem. And double metal plate thermal switch after using for a long time will be due to causes such as material or excessive torque temperature point shift up and down, also, the principle of switch, current is too large, also because the water into the ash, combined contact pressure decreases, and the various reasons appear contact moment not connected or connected. Compared two kinds of thermal switch, double metal plate has developed more mature, its structure, sensitivity, and defects such as life properties are better than wax thermal switch, thus the wax thermal switch, also will slowly fade out.

Thermal switch principle

Thermal switch is widely used in life, such as fluorescent lamp, such as hot kettle, an essential component in the industry is also a car. Believe that after long time of development, all kinds of flaws of the thermal switch will be less and less, the quality of people's life will be more and more is also high.