I have a question: after a switching power supply converts AC 220V to DC 24V, is there a proportional relationship between the values of the AC and DC currents?
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As the title suggests, there is a Mingwei switching power supply in the PLC cabinet, which converts 220V AC to 24V DC to power the instruments below. When using a clamp meter to measure the current, it shows around 11 amps on the DC side; why is the current around 1 amp on the AC side? Is there a proportional relationship here? I had never thought about this before; could you please advise?
AC power * power factor = DC power
Input power = Output power + Power consumption by the power supply + Reactive power. Input power = 220V × 1A = 220VA. Output power = 24V × 11A = 264VA. The difference between the two is the power consumed by the power supply (power consumption by the power supply + reactive power loss)
There is a connection, but AC220V refers to the effective value of the voltage; the voltage after rectification is actually around DC310V. Then it’s just a matter of calculating the input and output power.