Introduction of how to choose the model of switching power supply
Nowadays, switching power supply has penetrated into every aspect of our lives. However, there are many switching power supplies, which correspond to different voltage ranges, power and load characteristics, etc. Many people are puzzled about how I should choose switching power supplies. The following is how to choose switching power supply. In the process of choosing switching power supply, you can pay attention to these problems, and then choose regular switching power supply products as much as possible, so the use effect will be much better.
Determine what kind of switching power supply you need from the following aspects:
1) Input type and output voltage
Input and output types can be roughly divided into: ① AC/DC; ②DC/DC； ③AC/AC； ④DC/AC。
Note: AC is AC and DC is DC. For example, AC/DC is AC input and DC output.
The commonly used input voltage specifications are 110V and 220V, so there are three specifications of 110V and 220V AC switching and general input voltage (AC: 85 V-264 V). Input voltage specifications should be selected according to the use area.
2) Switching power supply function
① Stabilized switching power supply: the input voltage and output voltage are rated at a certain value; ② SCR switching power supply: the output voltage can be changed by adjusting the input voltage; ③ Adjustable switching power supply: within the rated range of input voltage, the output voltage and current can be adjusted by means of potentiometer.
3) Load characteristics of switching power supply
In order to improve the reliability of the system, it is suggested that the switching power supply should work at 50%-80% load, that is, assuming the power used is 20W, the switching power supply with output power of 25W－40W should be selected. If the load is a motor, a light bulb or a capacitive load, the current is large at the moment of starting, so a suitable power supply should be selected to avoid overload. If the load is a motor, voltage backflow during shutdown should be considered.
4) switching power supply power
Long-term full-load use of switching power supply will affect its service life, so when selecting power supply, it is recommended to choose models with more than 30% rated output power.
5) Ambient temperature
In addition, it is still necessary to consider the working environment temperature of the power supply and whether there are additional auxiliary cooling equipment. If the ambient temperature is too high, the power supply needs to be derated. Reference should be made to the derating curve of ring temperature to output power.
