Automotive NTC thermistor produced by EXSENSE Electronic Technology Co., Ltd. has the characteristics of high precision, great reliability and high sensitivity. It plays the role of temperature monitoring and temperature controlling in electric vehicles, automobiles, motorcycles, etc.

Today, the whole society is increasingly concerned about the environmental protection problem. Electric vehicle is favored by more and more people because of their convenience, speed, efficiency and environmental protection, the application and development of electric vehicle is becoming a trend. With the increasing popularity of electric vehicle, more attention has been paid to the safety of charging of electric vehicle. Such as battery of electric vehicle due to quality reasons in the case of unattended, long time charging still can not be full, resulting in charging line overheating, easy to cause aging and fire; Another example is that the battery of electric vehicle in summer or in a closed environment will cause the charging device itself to overheat and fire; Another example is that the battery of electric vehicle fails to power off in time after it is fully charged, which will cause the overcharging of the battery to make the battery heat, bulge and even cause the battery explosion. In order to ensure the safety during the process of charging, it is particularly important to design a charging protector with the protection functions of timing power off, overheating power off, full power off and preventing the charging circuit from starting itself.

Electric vehicle charging protector, its purpose is to add functions of delay power off, overheating power off and full power off for the existing charger, which can effectively save costs and improve efficiency. The protector comprises an NTC thermistor, two voltage comparators, two time relays and an intermediate relay. Connect the positive pole of the first voltage comparator in series with the normally open contact of the intermediate relay and the charging line; The normally open contacts of the two time relays are connected in parallel with the NTC thermistor and connected in series with the negative pole of the first voltage comparator; The output end of the first voltage comparator is connected with the base of the first audion, its emitter is connected with the first intermediate relay, its collector is connected with the positive pole of the second voltage comparator; The output end of the second voltage comparator is connected to the base of the second audion, and its emitter is connected to the second time relay.

Automotive NTC thermistor as a negative temperature coefficient thermistor, its resistance value at room temperature is very large, equivalent to the circuit disconnect. When the temperature is overheated and reaches the operating temperature of the thermistor (generally choose NTC thermistor with operating temperature of 75℃), the resistance value of the thermistor decreases rapidly, which is equivalent to circuit closure. Using this characteristic, NTC thermistor can play the role of temperature monitoring in electric vehicle charging protector.