Transformers and Power Supplies
Power Supply Efficiency Calculator
Power Supply Efficiency Calculator is meant for one defined transformers and power supplies case. Run a separate case when the equipment, period, or connection changes.
Calculate Power-supply efficiency
Avoid mixing nameplate, measured, and billing values in Power Supply Efficiency unless that mix is intentional.
Where Power Supply Efficiency fits
Use the page when power-supply efficiency needs to be checked without rebuilding the equation by hand. The surrounding notes define how far the number should be carried.
If two cases differ in dc output power, save them as separate runs. A blended entry can hide the reason the power-supply efficiency changed.
Testing dc output power
Using the sample values, DC output power = 450 W; AC input power = 520 W, the primary result is 86.54%.
This Power Supply Efficiency one-input test is a scale check, showing direction and sensitivity without turning the changed case into a recommendation.
If the changed ac input power comes from a real measurement, keep the original Power Supply Efficiency run so the source of the difference remains clear.
The Transformer Efficiency page can be useful as a follow-up, but only after the present inputs have been checked.
Unit handling for Power Supply Efficiency
A clean Power Supply Efficiency result confirms the arithmetic for power-supply efficiency; it does not prove the equipment rating or source data is the right one.
Only the entries shown on Power Supply Efficiency feed power-supply efficiency. If another correction factor matters, keep it in the notes or make a separate run.
Source notes for Power Supply Efficiency
Collect DC output power, and AC input power from the same operating case before reading power-supply efficiency.
- DC output power
- Enter DC output power in W. Default shown: 450 W.
- AC input power
- Enter AC input power in W. Default shown: 520 W.
Interpreting Power Supply Efficiency
When power-supply efficiency is copied into notes, include the unit and the assumption that controls the result more than display precision does.
What Power Supply Efficiency leaves out
Efficiency varies with load and line voltage.
- Switching losses
- Ripple current
A numerically valid Power Supply Efficiency result can still be wrong if the field condition, connection type, tariff period, or equipment rating does not match.
Common Power Supply Efficiency questions
Why might a real measurement disagree?
A field reading for Power Supply Efficiency can include losses, tolerance, temperature effects, waveform distortion, or instrument limits that the worksheet does not model.