When selecting switching power supply, the input voltage range, appropriate power, load characteristics and working ambient temperature shall be considered.
1. Select appropriate input voltage range. Taking AC input as an example, the commonly used input voltage specifications are 110V and 220V, so there are three specifications: 110V, 220V AC switching and general input voltage (AC: 85v-264v). The input voltage specification shall be selected according to the region of use.
2. Select the appropriate power supply. The switching power supply consumes part of the power supply during operation and is released in the form of heat. In order to improve the service life of the power supply, it is recommended to increase the output power rating by 30%.
3. Considering the load characteristics, in order to improve the reliability of the system, it is recommended that the switching power supply should work under 50% ≤ 80% load, that is, assuming that the power used is 20W, the switching power supply with output power of 25W ~ 40W should be selected.
If the load is a motor, bulb or capacitor load, select an appropriate power supply to avoid overload when the current is large at startup. If the load is a motor, the voltage backfill shall be considered when the load drops.
4. In addition, the working ambient temperature of the power supply and the availability of additional auxiliary heat dissipation equipment shall be considered to reduce the output of the power supply with excessive ring temperature. The output power drop curve of the ring temperature shall be referred to.
