Transformers and Power Supplies
Power Supply Efficiency Calculator
Estimate power-supply efficiency with Power Supply Efficiency. The page keeps the formula, assumptions, and example values visible.
Enter values for power-supply efficiency
Use one consistent electrical operating case for all fields.
How Power Supply Efficiency works
The page evaluates efficiency = output ÷ input × 100. Power Supply Efficiency uses DC output power, AC input power to report Power-supply efficiency.
With the loaded values, power-supply efficiency evaluates to 86.54%. Test one input at a time and save the original case.
Inputs for Power Supply Efficiency
DC output power and AC input power belong to Power Supply Efficiency. Keep source units with dc output power.
The initial entries illustrate operation only. Use current records, readings, or nameplate values for planning.
- DC output power
- Example entry: 450 W.
- AC input power
- Example entry: 520 W.
Reading the Power Supply Efficiency result
This output represents Power Supply Efficiency.
Use the result as a planning quantity before checking available ratings and protective requirements.
Measurement and units
Check component ratings, isolation requirements, temperature, waveform, and manufacturer limits. Check prefixes on dc output power.
Reconcile prefixes and units before comparing outputs.
Limits of this calculation
Efficiency varies with load and line voltage.
This worksheet does not model every behavior in the surrounding system. Unentered effects remain outside Power Supply Efficiency.
Power Supply Efficiency record notes
Record source and operating details for dc output power. For copper loss, use Transformer Copper Loss Calculator.
Retain raw power-supply efficiency beside its selected rating.
Questions about Power Supply Efficiency
What does Power Supply Efficiency calculate?
It evaluates power-supply efficiency from dC output power and aC input power using the displayed formula.
Can DC output power be zero?
For Power Supply Efficiency, measure any zero dc output power directly.
Why can power-supply efficiency differ from measurement?
Efficiency varies with load and line voltage. Recheck dc output power.
Should the result be rounded?
Keep extra digits while comparing cases, then round to the precision supported by dC output power.