Maintenance Guide for High Power Switching Power Supply
With the development of modern electronic technology, electronic equipment has become more and more complex, so the load requirements on the power supply are also getting higher and higher. Although the traditional regulated power supply has better stability and is more reliable in use, it needs to be equipped with large and heavy transformers and filters, so it is difficult to meet the needs of flexibility. At this time, the advantages of switching power supply began to emerge, and it was applied in a wider range of fields due to its advantages of small size, light weight and high efficiency. For the control and protection of high-power switching power supply, we should master some knowledge about its failure and maintenance to ensure the reliability of the power supply during use.
The first kind of possible failure is that the fuse of the power supply is burned or the tube is blown. Our maintenance work should be carried out in the following steps: First, we should mainly check the key parts such as the rectifier bridge, diodes, and large filter capacitors. If no problem is found, go to check again. Whether there is a problem with the anti-jamming circuit.
The second type of fault is that the fuse is normal, but the power supply still has no voltage output. This is that we should first measure whether there is a starting voltage. If the voltage is zero or very low, we should check whether there is any component leakage in the starting pin, so that the fault location can be detected. If there is a starting voltage, it may be that the control chip or the protection circuit is faulty. At this time, we can find out the fault by checking one by one.
The third type of fault is that the output voltage of the power supply is too high. The reason for this kind of failure is generally that there is a problem with the voltage regulator control circuit. This problem may occur in any component in this closed circuit, including optocouplers, control chips, and so on. The fourth type of failure is just the opposite, the output voltage of the power supply is too low, and there are many reasons for this situation. One is that there is a short circuit in the circuit; the other is that the conduction function of the switch tube fails, which leads to an increase in the internal resistance of the power supply but a decrease in the output voltage; something is wrong.
In the case of many failures, if there is a problem with the switch tube, the power must be cut off immediately, otherwise it will easily cause the switch tube to burn out. After disconnecting the power supply, we will replace the switching tube and conduct other troubleshooting.
