Common problems in using switching power supply
1. What should I pay attention to when choosing switching power supply?
Answer: In order to prolong the service life of the switching power supply, it is recommended to choose a model with more than 30% rated output power. For example, if the system needs a 100W power supply, it is suggested to choose a power supply with an output power greater than 130W, and so on, which can effectively improve the life of the power supply. In addition, it is necessary to consider the working environment temperature of the power supply and whether there are additional auxiliary heat dissipation equipment. The rated output of the power supply will be reduced at too high ambient temperature. Select various functions according to application requirements: protection functions: over-voltage protection (OVP), over-temperature protection (OTP), over-load protection (OLP), etc. Application functions: signal function (POWER GOOD, POWER FAIL), remote control function, telemetry function, parallel function, etc. Special functions: power factor correction (PFC), uninterruptible power supply (UPS). Select the required safety regulations and electromagnetic compatibility (EMC) certification.
2. Can POWER be used at 45~440Hz? If so, are there any other impacts?
A: Switching power supplies can generally be used in this frequency range. However, if the frequency is too low, the efficiency will decrease. For example, when the input voltage is 230VAC and the rated load is 230VAC, the efficiency will be 84% when the input AC frequency is 60Hz, but if the input AC frequency is reduced to 50Hz, the efficiency will be 83.8%. If it is too high, the PF value of the model with PFC function will decrease, and it will also increase the leakage current. For example, when the input AC frequency is 60Hz, the power factor is 0.93 and the leakage current is 0.7mA at 230VAC and rated load; When the frequency of input alternating current is 440Hz, the power factor decreases to 0.75 and the leakage current increases to 4.3mA.
3. If 24V voltage is needed, but Gaoxin does not have this model, can two 12V series devices be used?
Answer: Yes, but it should be noted that the * small current in the series model is the maximum current required by the whole system after series connection. In addition, in order to prevent the possibility of internal capacitance damage caused by the series power supply when starting, it is suggested that the SPU output terminal be connected in parallel with the diode.
