How to pick a switching power supply model
Nowadays, switching power supply has penetrated into every aspect of our life. However, there are so many switching power supplies, and they correspond to different voltage ranges, power, load characteristics, etc., many people are entangled, how should I choose a switching power supply. The following is how to choose a switching power supply. In the process of selecting a switching power supply, you can pay attention to these problems, and then choose a regular switching power supply product as much as possible, so that the effect of use 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: ①AC/DC; ②DC/DC; ③AC/AC; ④DC/AC.
Note: AC means alternating current, DC means direct current, such as AC/DC means AC input and DC output.
The commonly used input voltage specifications are 110V and 220V, so there are three specifications of 110V, 220V AC switching, and universal input voltage (AC: 85V-264V). The input voltage specification should be selected according to the area of use.
2) Switching power supply function
①Stabilized switching power supply: the input voltage and output voltage are rated at a certain value; ②Thyristor switching power supply: the output voltage can be changed by adjusting the input voltage; ③Adjustable switching power supply: within the rated range of input voltage, the output voltage and current can be passed potentiometer, etc. to adjust.
3) Switching power supply load characteristics
In order to improve the reliability of the system, it is recommended that the switching power supply work at a load of 50%-80%. That is, assuming that the power used is 20W, a switching power supply with an output power of 25W-40W should be selected. If the load is a motor, a light bulb or a capacitive load, the current will be relatively large when the power is turned on, and an appropriate power supply should be selected to avoid overload. If the load is a motor, the voltage backflow during shutdown should be considered.
4) switching power supply power
The long-term full-load use of switching power supply will affect its life, so when selecting the power supply, it is recommended to choose a model with 30% more output power rating.
5) Ambient temperature
In addition, the working environment temperature of the power supply and whether there is an additional auxiliary heat dissipation device must be considered. If the ambient temperature is too high, the output of the power supply must be derated. Refer to the derating curve of ambient temperature versus output power.
