Rectifier Efficiency
η = Pdc / Pac
Quick answer
This calculator solves η = Pdc / Pac for Efficiency. With DC Output Power 10 W, AC Input Power 22 W, the result is 45.45 %. It solves in 3 directions, so you can enter the values you have and get the one you need.
Calculator
Formula
Description
Rectifier conversion efficiency is the ratio of useful DC output power to the AC input power. It has a theoretical ceiling because the rectified waveform contains AC harmonics that do not contribute to the DC term: about 40.6% for an ideal half-wave rectifier and 81.2% for a full-wave rectifier. Real efficiency is lower still due to diode drops and transformer losses.
Variables
- η — Conversion efficiency (fraction)
- Pdc — DC power delivered to the load (W)
- Pac — AC power drawn from the source (W)
Practical Notes
The full-wave maximum (81.2%) is double the half-wave value because both half-cycles deliver power. This ceiling is why linear supplies are inefficient and switch-mode designs dominate above a few watts.
Symbols and units
| Symbol | Meaning | Default unit | Accepted units |
|---|---|---|---|
| eta | Efficiency | % | —, % |
| Pdc | DC Output Power | W | µW, mW, W, kW |
| Pac | AC Input Power | W | µW, mW, W, kW |
Step by step
- 1. What you know: DC Output Power 10 W, AC Input Power 22 W
- 2. The relation: η = Pdc / Pac
- 3. Substitute: Pdc = 10 W, Pac = 22 W
- 4. Result: Efficiency = 45.45 %
Worked examples
Minimum range
Given: DC Output Power 10 mW, AC Input Power 22 mW
Result: Efficiency = 45.45 %
Low range
Given: DC Output Power 100 mW, AC Input Power 0.22 W
Result: Efficiency = 45.45 %
Typical
Given: DC Output Power 10 W, AC Input Power 22 W
Result: Efficiency = 45.45 %
High range
Given: DC Output Power 1 kW, AC Input Power 2.2 kW
Result: Efficiency = 45.45 %
Maximum range
Given: DC Output Power 10 kW, AC Input Power 22 kW
Result: Efficiency = 45.45 %
Solving for each variable
Solve for Efficiency
DC Output Power 10 mW, AC Input Power 22 mW → 45.45 %
Solve for DC Output Power
Efficiency 0.5 %, AC Input Power 22 mW → 110 µW
Solve for AC Input Power
Efficiency 0.5 %, DC Output Power 10 mW → 2 W
How Efficiency changes with DC Output Power
| DC Output Power (input) | Efficiency (result) |
|---|---|
| 1 W | 4.545 % |
| 2.5 W | 11.36 % |
| 5 W | 22.73 % |
| 7.5 W | 34.09 % |
| 10 W | 45.45 % |
| 15 W | 68.18 % |
| 20 W | 90.91 % |
| 40 W | 181.8 % |
| 70 W | 318.2 % |
| 100 W | 454.5 % |
The same result in other units
| Unit | Value |
|---|---|
| % | 0.4545 |
| % | 45.45 |
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<p><a href="https://vbatpower.com/formulas/rectifier-efficiency/">Rectifier Efficiency</a> Calculator by vbatpower.com</p>Frequently asked questions
How do you calculate Rectifier Efficiency?
Use η = Pdc / Pac. With DC Output Power 10 W, AC Input Power 22 W, Efficiency works out to 45.45 %.
What is the formula for Rectifier Efficiency?
The formula is η = Pdc / Pac. Rectifier conversion efficiency is the ratio of useful DC output power to the AC input power.
How do you find DC Output Power when you know the other values?
Rearrange for DC Output Power: with Efficiency 0.5 %, AC Input Power 22 mW, DC Output Power is 110 µW.
How do you find AC Input Power when you know the other values?
Rearrange for AC Input Power: with Efficiency 0.5 %, DC Output Power 10 mW, AC Input Power is 2 W.
What units does Rectifier Efficiency use?
Efficiency is shown in %, %. Values are held in SI base units internally, so you can mix prefixes without converting by hand.
Related Concepts
All Power & Efficiency formulas →Need more features?
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