How thermistor works

Thermistorswill maintain a non-working life for a long time; When the ambient temperature and current are in zone C, the heat dissipation system power of the thermistor can be close to the heating power, so we may or may not work. At the same ambient temperature, the working time of the thermistor decreases sharply with the increase of the current. When the ambient temperature is high, the thermistor has a short working time and a small maintenance current and working current

PTC effect means that the material has a positive temperature coefficient (PTC) effect, which only means that the resistance of the material increases with the increase of temperature. For example, most metal materials have PTC effect. Among these materials, PTC effect research shows that a resistance increases linearly with the temperature rising, which can be called linear PTC effect

Nonlinear PTC effect After phase change, the resistance of the material will increase sharply by several to more than ten orders of magnitude along a narrow temperature range, that is, nonlinear PTC effect, a considerable number of conductive polymers will show this effect, such as polymer PTC thermistor. These conductive polymers are used to manufacture overcurrent protection devices

Polymer PTCthermistorsare used for overcurrent protection. Polymer PTC thermistors are often referred to as self-recovery fuses (hereinafter referred to as thermistors). Because of their unique positive temperature influence coefficient resistance characteristics, we are very widely used for overcurrent protection working devices. Thermistors are used in series like conventional fuses in the circuit

When the circuit works normally, the temperature of the thermistor is close to room temperature, the resistance is very small, and the series connection will not prevent the current from passing through the circuit; When the circuit overflows due to faults, the temperature of the thermistor increases with the increase of heating power. When the temperature can exceed a switch control temperature), the resistance will generate a surge instantly, and the current in the circuit will drop to the safe value more rapidly. It is caused by current change in the process of AC circuit thermistor protection. After the thermistor operates, the current in the circuit is greatly reduced, and T is the thermistor operation time. Due to different polymer PTC thermistors, a good design is carried out

But by constantly changing the control temperature of the enterprise's own safety switch to adjust its sensitivity to temperature, we can develop two important functions of over-temperature protection and over-current protection. For example, the 16-1700 thermistor is generally applicable to the over-current and over-temperature protection of lithium-ion batteries and nickel metal hydride batteries due to its extremely low ambient temperature

Polymer PTCthermistorcan be reused because the resistance can be recovered. It shows the change of resistance with time during the recovery process of thermistor. The resistance can be restored to about 1.6 times the initial value in 10 seconds to tens of seconds. At this time, the maintenance working current technology of the thermistor has begun to recover to the rated value, and can be used again. Thermistors with small area and thickness recover relatively quickly; The recovery of thermistors with large area and thickness is relatively slow