A new PTC heater protection circuit

By designing a high-voltage sampling circuit and a comparison protection control circuit, the voltage is monitored in real time and the connection is cut off at the moment of abnormality, which solves the problem of damage to PTC heaters caused by sudden load changes and achieves efficient and economical protection.

CN224385064UActive Publication Date: 2026-06-19DONGGUAN SAIERYING ELECTRONICS CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
DONGGUAN SAIERYING ELECTRONICS CO LTD
Filing Date
2025-05-27
Publication Date
2026-06-19

AI Technical Summary

Technical Problem

In the prior art, the PTC heater of electric vehicles is prone to a sharp increase in high-voltage bus voltage due to load dumping phenomenon when the load changes suddenly, which can damage the heater and other high-voltage components.

Method used

A novel PTC heater protection circuit, comprising a high-voltage sampling circuit and a comparison protection control circuit, was designed. By monitoring the voltage in real time and quickly disconnecting the PTC heater from the high-voltage bus at the moment of abnormality, the circuit combines hardware and software dual protection mechanisms to prevent IGBT breakdown and heater damage.

Benefits of technology

It effectively prevents PTC heaters from overheating or burning, ensuring vehicle safety. It has a simple structure, low cost, high reliability, and provides an efficient overvoltage protection solution.

✦ Generated by Eureka AI based on patent content.

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Abstract

This invention provides a novel protection circuit for a PTC heater, comprising a high-voltage sampling circuit and a comparison protection control circuit. The high-voltage sampling circuit includes a fifth resistor, a sixth resistor, a seventh resistor, and a first capacitor. One end of each of the fifth, sixth, and seventh resistors, and one end of the first capacitor, are electrically connected to the input terminal of the comparison protection control circuit. The other ends of the sixth, seventh, and first resistors are grounded. In this invention, when the bus voltage rises sharply under specific operating conditions, the high-voltage sampling circuit and the comparison protection control circuit monitor the voltage in real time and quickly disconnect the PTC heater from the high-voltage bus at the moment of abnormality, preventing IGBT breakdown and avoiding damage to the heater. The circuit consists only of basic components such as operational amplifiers, resistors, and diodes, and has the advantages of simple structure and low cost, providing an efficient and economical overvoltage protection solution for high-voltage systems in new energy vehicles.
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