Oct. 25, 2021
In order to prevent the hazards caused by surge currents, appropriate protection devices must be installed in the circuit. This article will tell you how a thermistor protects the device, so read on to learn!
Negative Temperature Coefficient Thermistor (NTC):
When the power supply is applied to a negative temperature coefficient circuit, the resistance of the negative temperature coefficient thermistor is very high at the beginning, and the converter is in a stable state after the surge current flows. The temperature of the negative temperature coefficient thermistor increases, and the resistance decreases.
Negative temperature coefficient thermistors limit the inrush current only when the temperature is low. When the power is turned off and then turned on quickly, since the negative temperature coefficient thermistor has no time to cool down, the inrush current cannot be limited. In order to limit the inrush current, the NTC must be connected in series with the load circuit. Surge current limiting components can be used in series to obtain higher suppression, and cannot be used in parallel.
Positive temperature coefficient thermistor (PTC):
PTC thermistors are also used to replace traditional fuses for overcurrent protection. The PTC thermistor not only responds to unacceptably high currents, but also responds to exceeding the preset temperature. They reduce the current by increasing the resistance, thereby reducing power consumption.
The PTC thermistor's voltage-current characteristic curve makes it an ideal choice for short-circuit or over-current protection devices. When connected in series with the load, the PTC thermistor is in a low resistance state, and the attenuation of the current is negligible. When a short circuit or overcurrent occurs, the PTC thermistor will switch to a high resistance state, thereby limiting the current far below the normal operating level. When the fault is eliminated, the PTC will return to a low resistance state, so that the current returns to a normal level.
The above content is about how the thermistor realizes the purpose of overcurrent protection. Hopefully the content of this article can be helpful to everyone. Dongguan Zhixu Electronic Co., Ltd. (also JYH HSU(JEC)) has a full range of varistor and capacitor models. JEC has passed ISO9001:2015 quality management system certification; JEC safety capacitors (X capacitors and Y capacitors) and varistors have passed national certifications of the main industrial powers across the world; JEC ceramic capacitors, film capacitors and super capacitors are in compliance with environmental protection indicators. Welcome to contact us for free samples and any questions.
Oct. 25, 2021
The Pros and Cons of Metallized Film Capacitors
Oct. 25, 2021
Do You Know What a Varistor Is?
Oct. 25, 2021
+86 181 2299 5593
+86 18122995593
+86 769 8831 3605
Beside Luchong Bridge, Hou Road, Caibai Village, Daojiao Town, Dongguan, Guangdong, China
Navigation
