1. Input voltage

China is generally 220V. Due to the instability of the grid voltage, a wide voltage input is often required, so it is designed to work normally at 90-270V. Usually the US electricity range is 110-130V, and Japan’s electricity range is 100V.

2. The ripple of the output voltage

Since the voltage regulation process of the switching power supply is a process of continuous sampling and feedback adjustment, there will be a fluctuation in the output DC voltage. ripple voltage. The smaller the value, the better the output characteristics. Generally, it is expressed by peak-to-peak value Vpp or effective value Vrms; generally, the ripple is required to be less than 1% of the output voltage.

3. Voltage adjustment rate

When the load remains unchanged and the input AC voltage changes, the relative change of the output voltage. This indicator is used to verify whether the output meets the requirements for wide voltage input.

4. Input voltage range

Under the premise that the output characteristics remain unchanged, the input voltage changes, and this change range is the input voltage range. The wider the range, the stronger the ability of the power supply to adapt to changes in mains power.

5. Conversion efficiency

Conversion efficiency is the ratio of output power to input power, the higher the efficiency, the better. At present, the efficiency of switching power supply can reach 90%.

6. Load regulation

Under the rated condition of input AC 220v, when the output current is no-load from the minimum value to the maximum value, the relative change of the output voltage. This indicator is generally used to verify the load capacity of the switching power supply.

7. Rated power

Rated power refers to the effective power that can be continuously output, and is the most important parameter specification of the power supply. In order to ensure the safety of the power supply and meet the power requirements used by the equipment, a certain margin is required for the output power.

8. Static power consumption

When the power supply is turned on, even if there is no load, the power supply itself will have a certain power loss. tube or IGBT. Generally, the current flowing through the chip is relatively small, and the power consumption will be lower. Generally, the greater the power of the power supply, the greater the static power consumption, generally in the range of several watts to tens of watts.

9. Power supply ripple rejection ratio (PSRR)

The power supply ripple rejection ratio is the ratio of the input power variation to the output power variation, and the unit is decibel (dB). PSRR is a quantity used to describe the output signal affected by the power supply. The larger the PSRR, the less the output signal is affected by the power supply.

10. Ripple coefficient

Ripple coefficient is a term used to characterize the quality of various voltage and current waveforms. We use the ratio of the maximum value of the fundamental wave of the AC component of the output voltage to its average value. The larger the ratio, the worse the waveform; otherwise, the better.

11. Whether the protection circuit is normal

Such as undervoltage protection, overvoltage protection, overcurrent protection, short circuit protection, etc.