Operation Principles Of Electric Heating Plate

Heating plate :

This is the main heating element of the rice cooker. It is an aluminum alloy disc with a built-in electric heating tube, and the inner pot is placed on it, which can be seen when the inner pot is taken out.

Temperature limiter :

It is equipped with a permanent magnetic ring and a spring, which can be compressed and is located in the center of the heating plate. When cooking rice, when the cooking switch is pressed, the toggle switch is driven by the suction of the magnet, keeping the power contacts open.

Isolation switch:

It consists of a spring-loaded sheet, a pair of normally closed contacts, a pair of normally open contacts, and a bimetallic sheet. As the rice cooks, the temperature in the pan will rise. Due to the different rates of thermal expansion and contraction of the two sheets that form the bimetallic strip, the bimetallic strip is bent upwards.

Lever switch:

The switch is entirely mechanical and has a normally open contact. When cooking rice, press this switch, the heating tube is energized and the heating indicator light is energized at the same time. When the meal is ready, the thermostat appears and activates the toggle switch to open the contacts. After that, the heating tube is controlled only by the keep warm switch.

Current limiting resistor :

The appearance is mainly golden or white, and the size is like a 3W resistor. It is pressed between the heating tube and the power supply to protect the heating tube. The commonly used current limiting resistor is 185C 5A or 10A (depending on the power of the rice cooker). The current limiting resistor is a key element to protect the heating tube and can be replaced by a wire.