FAQ No. FAQ01858
What is the best way to estimate the amount of heat produced by the Power
The Power Supply's internal loss becomes heat energy (internal loss = heat
Internal loss (W)
= Effective input power - Output power
= Output power/Efficiency - Output power
Note: Reducing the load rate is an effective way to reduce the amount of
Example Calculating the Heat Produced by a 100-W S82K Switch Mode Power Supply
Power rate: 80%
Output power: 24 V × 4.2 A = 100.8 W
Effective input power: Output power/Efficiency = 100.8 W/80% = 126 W
Internal loss (heat produced): 126 W - 100.8 W = 25.2 W
To convert the internal loss to calories:
By Joule's law, 1 W = 0.24 cal/s,
so 25.2 W = 25.2 × 0.24 cal/s = 6.05 cal/s
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