concept
Overheat protection, as the name suggests, is to activate the corresponding protection function when the temperature exceeds a certain threshold. Electronic devices will generate heat when they work, so most of them have overheat protection, and protection will be activated when the corresponding threshold is exceeded. For example: such as motor overheat protection, power device overheat protection, etc.

Continuously operating electromechanical equipment such as automatic lathes, electric ovens, ball mills, and other unattended equipment used in production. Because accidents caused by overheating or thermostat failure occur from time to time, corresponding protective measures must be adopted.


principle
Generally, a thermally sensitive bimetallic switch is used to build an overheat protection circuit. When the temperature sensor detects that the temperature of the main circuit device rises to a certain value, the internal low melting point metal will be deformed, and then the main circuit will be disconnected to achieve the purpose of protecting the main circuit device; The sensitive element detects that the temperature of the main circuit device has decreased, and the internal low melting point metal restores its original shape, thereby turning on the main circuit, and the main circuit device can work normally.


What about the form of overheating protection for communication power supply equipment that itself provides electrical energy to other equipment? There are two main ways.
1. When the temperature is too high, switch to other power supply equipment; after the temperature drops, the power supply will resume working. As shown in Figure 1.
The temperature is too high, cut the power supply

2. When the temperature is not too high, improve the internal ventilation conditions of the power supply and actively dissipate heat to the power supply. as shown in picture 2.