Step 1: Determine the Actual Power of the Load
First, calculate the total power of all downstream devices, paying attention to distinguishing between rated power and peak power. For example, the starting current of inductive loads such as motors and printers can reach 3 to 5 times the rated value, so the calculation should be based on peak power.
Step 2: Select Based on 1.2 to 1.5 Times the Total Rated Power
General recommendation: Total rated power × 1.3. If the load is stable (such as LED strips), use a factor of 1.2; if there are frequent start-stop cycles or capacitive loads, use a factor of 1.5. For example, if the total load power is 100W, select a power supply of 130W to 150W.
Step 3: Verify Output Voltage and Current
Ensure the output voltage of the power supply matches the load requirements, and the rated output current of the power supply is no less than 1.25 times the total load current. Finally, reserve one output port for future expansion to avoid overload operation later on.