Power expansion electrical heating method and apparatus based on positive temperature coefficient device

Abstract

A power expansion electric heating method and device based on a positive temperature coefficient device, applying an operating voltage whose voltage is proportional to the resistance change of the PTC ceramic heating element on a PTC ceramic heating element and keeping its operating current at a substantially constant level . Compared with the prior art, the present invention makes the working voltage of the PTC ceramic heating element change with the change of resistance, and limits the maximum operating current of the PTC ceramic heating element at the same time, so that the operating voltage is reduced at low temperature, thereby limiting the maximum input current I to within the safe zone. When the temperature rises, increase its working voltage and expand its power, so as to protect the PTC ceramic heating element at low temperature, improve its service life, and quickly heat up at high temperature.

Description

technical field [0001] The present invention relates to electric heating technology, and more specifically, relates to an electric heating method and device applicable to electric soldering iron cores and the like, which can realize power expansion of positive temperature coefficient devices. Background technique [0002] Positive temperature coefficient (PTC) materials, such as PTC ceramic heating elements, have been increasingly used in electric heater products. For example, they can be used in electric heating products such as electric soldering irons. In products where the body is used as an electric heating source, the traditional method of making the PTC ceramic heating element heat and temperature control is to use a constant voltage heating method, that is, to provide a constant voltage to the PTC ceramic heating element. Due to the resistance value R of the PTC ceramic heating element It will change with the change of temperature T, and its change curve is as follow...

AI Technical Summary

Problems solved by technology

To increase or expand the power output at high temperature, it is necessary to increase its working voltage U, but after increasing the voltage, the current density flowing through the PTC ceramic heating element at low temperature is too large, which may shorten the service life of the PTC ceramic heating element; while at low temperature If the input current I is reduced and the working voltage U is reduced, the input power at high temperature cannot meet the requirements.

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