The safety specification of the power supply is a very important part

When the PC power supply is in use, it may be connected incorrectly or short-circuited. In addition, the power supply itself may malfunction and cause the output voltage to be abnormal. Therefore, in the design and manufacture of the power supply, safety specifications are a very important part. There are two aspects to the protection of the power supply, one is to prevent other accessories from being burned, and the other is to protect itself from damage.

The protection of the power supply to the outside is mainly over-voltage and under-voltage protection, which means that when the output voltage of the power supply is too high or too low to be normal, the power supply will stop working. This is very important for the whole machine, because all expensive components, such as CPU, hard disk, etc., are relatively fragile and are easily burned out due to high voltage.

In order to prevent this situation, it is necessary to monitor each output voltage of the power supply. The power designer’s approach is to sample the output voltage through a sampling circuit, and the sampled signal is then connected to the control part through a comparator. Once the output voltage is abnormal, the sampling signal will be reflected immediately, and the control part will be notified to shut down. This can effectively protect the motherboard, CPU, memory, hard disk, optical drive and other valuable components. Whether the power supply has fast overvoltage protection is very important for the whole machine. In order to prevent burning caused by excessive current, the power supply is equipped with a fuse.

The main job of the fuse is that when the current is suddenly too large, the fuse will burn out first. As long as the fuse is replaced, the power supply can continue to be used. Therefore, the fuse placement method is very important and must be designed to be replaceable. Now some manufacturers, in order to save costs Solder the fuse directly on the PCB (printed circuit board) of the power supply. Once the fuse is burned, the entire power supply will be scrapped together! Do not cut corners in this link!

Good power supplies mostly use fire-resistant PCBs. When consumers buy power supplies, they can find out whether the PCB of the power supply uses fire-resistant materials through the heat dissipation holes. Generally, the fireproof material No. 94V0 is used, which can withstand 105 degrees of high temperature. As for the use of 94V1 fireproof material, the temperature that can be tolerated is even higher. In addition, a heat shrinkable film must be added to the outside of each part of the power supply for protection to prevent electronic parts from short-circuiting due to moisture or dust.

The safety specification is based on the protection of the life and property of users, and has made strict regulations on the insulation and flame retardancy of raw materials for power supply and electrical products. Products that meet safety specifications not only require the power supply itself to meet safety standards, but also require manufacturers to have a complete safety production and quality assurance system. If not, it is easy to malfunction.