Bridge Rectifier Calculator

What Is a Bridge Rectifier?

A full-wave bridge rectifier uses four diodes to convert AC to pulsating DC. Both halves of the AC cycle contribute to the output, doubling the effective frequency compared with a half-wave rectifier.

Bridge Rectifier Voltage Formulas

Peak voltage from RMS input:

$$V_{\text{peak}} = V_{\text{rms}} \times \sqrt{2}$$

Average DC output (ideal, no diode drop):

$$V_{\text{avg}} = \frac{2}{\pi} \times V_{\text{peak}}$$

With silicon diode forward drops:

$$V_{\text{avg}} \approx V_{\text{peak}} - 2V_d$$

RMS output of the unfiltered full-wave waveform:

$$V_{\text{rms,out}} = \frac{V_{\text{peak}}}{\sqrt{2}}$$

Example: 120 V RMS input gives $V_{\text{peak}} \approx 169.71$ V and ideal $V_{\text{avg}} \approx 107.99$ V.

Related tools: Voltage Converter and Power Converter.

Frequently Asked Questions

Why multiply RMS by √2?

For a sine wave, peak voltage equals RMS times √2. The bridge rectifier output peak tracks the input peak (minus small diode drops).

What is V_d?

It is the forward voltage drop of one diode, typically about 0.7 V for silicon. Two diodes conduct per half cycle in a bridge, so subtract 2V_d from peak for a quick average estimate.

Does a capacitor change the average voltage?

Yes. A smoothing capacitor holds the output near peak between pulses, raising average DC toward V_peak minus ripple. This calculator shows the unfiltered full-wave values.

Why is V_rms,out equal to V_rms,in?

Full-wave rectification folds the negative half into the positive half. The RMS of that waveform equals V_peak/√2, which matches the original sine RMS.

Where are bridge rectifiers used?

They are common in linear and switching power supplies, battery chargers, and anywhere AC mains must become DC.

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What Is a Bridge Rectifier?

Bridge Rectifier Voltage Formulas

Frequently Asked Questions

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