Instructions for use of switching power supply
1, output calculation
Due to the high efficiency of switching power supply, which can generally reach more than 80%, the maximum absorption current of electrical equipment should be accurately measured or calculated when selecting its output current, so that the selected switching power supply has a high cost performance. Usually, the yield calculation formula is:
Where is = kif: is-rated output current of switching power supply;
If-the maximum absorbed current of electrical equipment;
K- margin coefficient, generally1.5 ~1.8;
2. Grounding
Switching power supply will produce more interference than linear power supply. Electrical equipment sensitive to * * * mode interference shall be grounded and shielded. According to EMC restrictions such as ICE 1000, EN6 1000, FCC, etc., the switching power supply should adopt EMC electromagnetic compatibility measures, so the switching power supply should generally be equipped with EMC electromagnetic compatibility filters. For example, the HA series switching power supply of Lide Hua Fu Technology can meet the above electromagnetic compatibility requirements only by grounding its FG terminal or connecting it to the user's chassis.
3. Protection circuit
Switching power supply must have protection functions such as over-current, overheating, short circuit, etc. Therefore, switching power supply module with complete protection functions should be preferred in design, and the technical parameters of its protection circuit should match the working characteristics of electrical equipment to avoid damaging electrical equipment or switching power supply.
4. Wiring method
L: Connect 220v AC live wire;
N: connected to 220v AC neutral line;
FG: grounding;
G: DC output place;
+5v: the port that outputs +5V;
ADJ: the output voltage is adjusted within a certain range. The rated voltage of switching power supply output is fixed at the factory, that is, the nominal rated output voltage. Setting this potentiometer allows users to adjust the output voltage in a small range according to the actual use situation, and generally no adjustment is needed.
Matters needing attention in the use of switching power supply
(1) Before using the power supply, please make sure that the input and output voltage specifications are consistent with the nominal values of the power supply used.
(2) Before powering on, check whether the input and output leads are connected correctly, so as not to damage the user equipment.
(3) Check whether the installation is firm, whether the installation screws are in contact with the power board device, and measure the insulation resistance between the shell and the input and output to avoid electric shock.
(4) In order to ensure safe use and reduce interference, please ensure that the grounding terminal is reliably grounded.
(5) Multi-output power supply is generally divided into main output and auxiliary output, and the characteristics of main output are better than those of auxiliary output. Generally, the output with large output current is the main output. In order to ensure the output load adjustment rate and output dynamics, it is generally required that each channel has at least 10% load. If the auxiliary road is used instead of the main road, the main road must be loaded with an appropriate dummy load. See the specifications of the corresponding model for details.
(6) Please note that frequent switching of power supply will affect its service life. Working environment and load degree will also affect its service life.
The above is a detailed answer about the choice of switching power supply. I wonder if you are satisfied with our introduction.