The electric heating element of the self-limiting heating belt is a core belt made of positive temperature coefficient semiconductor PTC material evenly squeezed between two parallel metal buses. When two buses at one end of the cable are connected to the power supply, the current flows laterally from one bus to the other bus through the PTC material layer. PTC layer is a resistance heater connected in parallel between buses continuously, which converts electric energy into heat energy and keeps the operating system hot. With the increase of temperature, the resistance of the core belt increases, and when it reaches the high resistance area, the resistance is so large that it almost blocks the current, and the core belt temperature reaches the high limit, but the temperature is automatically limited if the temperature does not increase. The output power of cable is mainly controlled by the heat transfer process and the temperature of heating system.
The self-limiting heating belt has the advantages of uniform temperature, no overheating, energy saving, rapid temperature rise, etc. It can be cut and used at will and overlapped within the longest service length of the selected heating belt. The self-limiting electric heating belt can improve the service life and the stability of heating temperature after irradiation.
Working principle and characteristics of constant power heating belt;
The power bus is two parallel insulated copper wires, and an electric heating wire is wound in the middle of the insulation layer. The electric heating wire is connected with the bus at a certain interval (that is, the length of the heating section) to form a continuous parallel resistance. After the bus is electrified, each parallel resistor heats up, forming a continuous heating area.