1. capacity: the larger the capacity, the better. Generally, it should not exceed 30%(330 uf) of the original value, so as to avoid excessive "surge current" and burn out important components such as the motherboard; Moreover, the capacity is proportional to the leakage current, and the leakage current is too large, which will increase the power consumption burden of the power regulator and reduce the overall efficiency;
2. Withstand voltage: Withstand voltage shall not be lower than the initial value (200V). Because these two capacitors are connected in series, the voltage at both poles is1.414 * 220 = 311.08 (v), which is less than 2*200V, so the original value is enough.
Volume: If the volume allows, of course, you can consider using large capacity and high voltage, but if you consider it comprehensively, it is better to strictly choose new capacitors. Specific practices are as follows:
1, prepare 1 12V power supply and digital multimeter (current range 1 ~ 10 mA), and form a series circuit with power supply, ammeter and measured capacitor. The connection method is as follows: the anode of the power supply is connected to the anode of the capacitor;
2. The leakage current of the capacitor should be less than 65438 00UA; If it is greater than 1mA, it should be eliminated.
In addition, if the landlord has the conditions, he can appropriately increase the area of the radiator inside the power supply, such as fixing a little aluminum and copper (0.5 ~ 1 mm thick) on the original radiator, which can improve the efficiency of the power supply (the heat dissipation efficiency is almost linear with the divergent power of the power supply) and increase the output power of the power supply.
But be sure to pay attention to the insulation between radiators and between radiators and shell to prevent short circuit. They can be separated by plastic film.
Finally, if your dormitory often trips and loses power, it is necessary to change the power supply. Specifically, connect 1 leakage resistance (500k ~ 1m/0.5 ~ 1w) in two high-voltage capacitors in parallel, and of course, pay attention to insulation.