Common problems when using switching power supply
What should be noted when choosing a switch power supply?
Answer: In order to increase the lifespan of the switching power supply, it is recommended to choose models with 30% more rated output power. For example, if the system requires a 100W power supply, it is recommended to choose a power supply with an output power greater than 130W, and so on, which can effectively improve the lifespan 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 devices. The rated output of the power supply will be reduced in high ambient temperatures. Select various functions according to the application requirements: protection functions: overvoltage protection (OVP), over temperature protection (OTP), overload 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) certifications.
2. May I ask if POWER can be used for 45~440Hz? If so, are there any other impacts?
Answer: Switching power supplies can generally be used within this frequency range. However, if the frequency of use is too low, it will cause a decrease in efficiency. For example, when the input voltage is 230VAC and the rated load is used, the efficiency is 84% when the frequency of the input AC power is 60Hz. However, if the frequency of the input AC power is reduced to 50Hz, the efficiency is 83.8%; When it is too high, it will cause a decrease in the PF value of models with PFC function, and 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 the input AC power is 440Hz, the power factor decreases to 0.75, while the leakage current increases to 4.3mA.
3. If a voltage of 24V is required and Gaoxin does not have this model, can two 12V units be connected in series?
Answer: Yes, but it is important to note that the minimum current of the series connected models should be taken as the maximum current required by the entire system after series connection. In addition, to prevent the possibility of internal capacitor damage caused by the series connected power supply during startup, it is recommended to connect a diode to the SPU output terminal.
If a 600W power supply is required, can two 300W units be connected in parallel?
Answer: It cannot be directly connected in parallel. Due to the general design of 300W without parallel function, when two power supplies have different output voltages, the higher voltage will bear most or all of the losses. It is recommended to use a model with parallel function.
Measure two sets of output power supplies,+5V is correct, but+12V exceeds the specification. What is the reason?
Answer: Multiple sets (2 or more) of output models in high-tech products have minimum load requirements. Please refer to the manual before use. When 5V/4A and 12V/1A are used, the 12V output voltage is too high, about 12.8V, which exceeds the ± 6% (12.72V) stated in the manual. If a minimum load of 0.2A is added to 12V according to the manual, the 12V output voltage can be reduced to about 12.3V.
