Circuits / Power
Bridge rectifier with a filter capacitor
Both half-waves come out positive; C1 fills the gaps between peaks (ripple)
Tap a part to see its voltages and currents. It is a model, not a measurement.
What do you need?
- Bridge rectifier KBP206Search on Amazon
- Resistor 1 kΩSearch on Amazon
- Red LEDSearch on Amazon
- Capacitor 470 µF 25 VSearch on Amazon
- Jumper wires × 5Search on Amazon
- BreadboardSearch on Amazon
How does a bridge rectifier turn AC into DC?
A bridge rectifier is four diodes arranged so that current always leaves through the + terminal, whichever way the AC is flowing. On each half of the wave two diodes conduct, so both halves come out positive: the 50 Hz input becomes a series of bumps at 100 Hz. Here the generator gives a 12 V peak sine to a KBP206 bridge. Each silicon diode drops about 0.7 V, so the output peaks near 10.6 V. Between peaks the voltage would fall to zero, so C1 (470 µF) fills the gaps: it charges at each peak and feeds the load in between. With R1 (1 kΩ) and the LED drawing about 9 mA, the voltage sags only about 0.2 V before the next peak. That sag is the ripple: a bigger capacitor or a lighter load makes it smaller.
Values calculated from the circuit and typical diode drops, not from the simulation.
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