Rectifier Output Calculator
DC output and ripple for half-wave or full-wave rectifier with filter cap.
How to Use
- Enter secondary Vrms, line f, topology, load current, bulk cap.
- Vpk = √2·Vrms − Vf. Ripple = I/(f·C).
Show Work
Formulas
History of Rectifiers
The first practical rectifier was Thomas Edison's 1883 observation of one-way current flow through a vacuum-tube filament — "the Edison effect" — which John Ambrose Fleming turned into the vacuum-tube diode in 1904. Fleming's valve enabled AM radio detection and became the first electronic rectifier in mass production, followed by mercury-arc rectifiers for industrial DC supplies in the 1920s.
Solid-state rectification emerged with the 1920s development of copper-oxide (CuO) rectifiers by L.O. Grondahl at Union Switch & Signal, and selenium rectifiers in the 1930s. Both were clunky (low efficiency, huge stacks for a few amps) but replaced vacuum tubes in power supplies, battery chargers, and welders. Silicon P-N diodes arrived in 1954 (Bell Labs) and displaced selenium by the early 1970s — 10× the current density with a tenth the forward drop.
The bridge rectifier topology predates semiconductors — patented by Polish engineer Karol Pollak in 1895 as a mechanical rotary device. Graetz wrote it up for general use in 1897 (hence "Graetz bridge" in European literature). Full-wave center-tap topology came earlier still (1880s) but required a center-tapped transformer. Today virtually all line-frequency rectification uses four-diode bridge configurations, either as discrete diodes or as single-part bridge modules (KBPC, GBPC series).
About This Calculator
Enter transformer secondary RMS voltage, line frequency, rectifier topology (half-wave, full-wave bridge, or center-tap), load current, bulk capacitance, and diode forward drop Vf (0.7 V silicon, 0.3 V Schottky — count one Vf for half-wave, two Vf for bridge). The tool returns peak DC (Vpk = √2·Vrms − n·Vf), peak-to-peak ripple Vr ≈ I/(f·C), average DC, and ripple frequency.
Rule of thumb for bulk cap sizing: 2000-3000 µF per amp of load current at 60 Hz full-wave gives ~2 V ripple — plenty for a downstream linear regulator to clean up. For offline rectifiers (120/230 VAC direct to bulk cap), add NTC inrush limiting or a precharge relay; cold bulk caps can draw 30-60× steady-state current on the first half-cycle. Everything runs client-side; no values leave your browser.
About the Rectifier Output Calculator
Use the Rectifier Output Calculator — a free, easy tool for electronics and circuit design. Nothing is uploaded, and you do not need an account. DC output and ripple for half-wave or full-wave rectifier with filter cap.
How it works
Put each value in its box and read the answer as you go. Because it recalculates live, you can play with the inputs to see how each one moves the result — handy for checking your own working or planning ahead. Everything happens on your device, so it is fast and private.
Want the deeper story? The Knowledge Base explains the ideas behind the tools in more detail.
Frequently Asked Questions
Full vs half?
Full-wave doubles ripple frequency and halves voltage.
Vf?
Silicon ~0.7 V, Schottky ~0.3 V (× 2 for bridge).
How do I use the Rectifier Output Calculator?
Simply type your numbers and read the result, which refreshes the instant you change something. There is nothing to submit and nothing to wait for.
Do I need to install or sign up for anything?
Not at all — it runs in the browser with nothing to install and no account. After it loads once, it even works without an internet connection.
Is my information private?
Yes. Everything happens in your browser. Nothing you type is sent to a server or saved anywhere.
Common Use Cases
Linear PSU
12V AC → 17V DC bus.
Offline
120V AC → 170V DC bus.
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