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A.
Power factor is the ratio of active power to apparent power. The larger the active power, the higher the power factor. The calculation method is listed below:
Power factor = Active power (W) / Apparent power (VA)
Apparent power: Active power + Reactive power
Active power: Power actually consumed by the device (load side)
Reactive power: Power not consumed by device (load side)
Calculation example (15W-24V output model): When obtaining the power factor from the actual usage environment
・Numerical values read from the actual usage environment: Specifications
Input voltage=100VAC
Output voltage=24V
Output current=0.65A (100%)
・Numerical values read from the data below:
Efficiency=85%
Input current=0.33A
・Calculated numerical value: Power factor, active power
Active power = Output voltage × Output current ÷ Efficiency = 24 × 0.65/85% = 18.4W
Apparent power = Input voltage × Input current = 100 × 0.33 = 33VA
Power factor = Active power/Apparent power = 18.4/33 = 0.55
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