Thermal Protection Advantages And Disadvantages

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Thermal protection is a method of detecting over-temperature conditions and disconnecting the electrical power. This usually used to prevent fires or damage to electronics power supplies and equipment which may arise from the high temperatures.
Temperature in power supplies rises due to both environmental factors as well as heat generated by the components themselves. There is heat from semiconductors such as transistors, ICs, switching devices, from transformers, inductors and resistors.
The amount of heat varies from one power supply to another and may be a factor of design, power capacity and load. Natural convention is adequate for removing the heat away from smaller power supplies and equipment; however, forced cooling is required for
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Resettable thermal fuses;

This type disconnects the current at designed temperatures and resets when the temperatures resumes to normal. The fuse ios made of two heat sensitive metallic leafs which are usually in contact during normal operation. When the temperature rises, the parts react to heat and bend in a way that they contact opens. This disconnects the circuit and prevents further heating. Once the temperature goes down, the parts fall back together and current starts flowing again.

2. Non-resettable thermal fuses

This is a one-time fusible link such as the electrical fuse and must be replaced every time it blows. This type of a fuse has temperature-sensitive link that melts due to the high temperature.

Non-Resettable Thermal Fuse 10 A +192°C, 277 V AC

Inbuilt protection in Integrated circuits
Some components such as ICS have inbuilt thermal overload protection which turns of the IC when temperatures exceed the safe limits. The protection, mostly used in regulators, processors and other ICs prevents damage to the IC and circuit against excessive heating. The protection shuts down the IC such that the input is reduced until the temperature comes down. In some designs, the increased temperature increases the resistance such that the current in order to reduce the temperature. In this condition, the circuit may operate at lower power as designed and its output will reduce accordingly. This happens in computer systems and leads to reduced performance such as slow
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