What are the precautions when choosing a switching power supply?
Points to note when selecting a switching power supply: Service life: In order to prolong the service life of the switching power supply, it is recommended to choose a power switch with an output power exceeding 30%. For example, if the device needs a 75W power supply, it is recommended to choose a switch with an output power of 100W, so as to effectively improve its service life. Pay attention to the ambient temperature when selecting a switching power supply: it is necessary to consider the working ambient temperature of the power switch and whether there is an additional auxiliary heat dissipation device, and the additional output needs to be reduced when the ambient temperature is too high. Choose stability and electromagnetic compatibility certifications that meet switching power supply requirements.
Overview of switching power supply characteristics:
(1) Switch the AC input range through the switch;
(2) 300VAC surge input can withstand 5 seconds;
(3) Short circuit/overload/overvoltage/overtemperature; (4) DC fan forced air cooling;
(5) Fan on/off control;
(6) Power start LED indicator light;
(7) The no-load power is less than 0.75W during remote shutdown;
(8) Full load aging test;
(9) The working temperature can be as high as 70°C;
(10) High efficiency, long life and high reliability.
How to do capacitive load test of switching power supply
The switching power supply capacitive load test refers to using a certain power load to test the transmission characteristics of the switching power supply under fixed or variable frequency and voltage. It can measure performance parameters such as switching power supply transmission efficiency, effective load and power consumption, and then analyze and judge them.
Generally speaking, the same or similar frequency, power and working conditions should be used for switching power supply capacitive load testing. In addition, pay attention to the differences between different switching power supplies when selecting inductors: for example, some need to use low-damping capacitive loads; others need to use large capacitive loads.
Before testing the capacitive load of the switching power supply, the instruments used should be checked, calibrated and regression tested. In addition, in order to ensure the accuracy of experimental data (such as calibration time, quantification accuracy, etc.): 1. When connecting the instrument to the part to be tested, all competent parts should be placed in a clean and dust-free place; All connections must be disconnected before placing the unit in a clean, dust-free area.
