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Rectification and smoothing
Intermediate
Convert AC to steady DC.
Diodes convert AC to pulsating DC; a capacitor smooths it and a regulator stabilises it. Ripple ∝ I/(fC).
Phone charger adaptors.
Larger C gives smoother output.
In more detail
Rectifiers convert AC to pulsating DC, and smoothing capacitors or filters reduce the ripple to a nearly constant DC output. Together they make the DC supply for electronics.
Real-world uses
- Phone chargers rectify and smooth mains AC.
- Laptop power adapters use smoothing capacitors.
- Phone chargers convert the mains AC to a smooth DC output using a rectifier and a smoothing capacitor.
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Frequently asked questions
What is ripple?
The residual variation in the DC output after rectification.
How does a capacitor smooth?
It charges at each peak and discharges slowly between peaks, supplying current to the load.
What is ripple?
The small variation that remains in a DC supply after rectification, which is reduced by smoothing.
Related topics in AC Circuits & EM Waves
Filters · Transformers in power transmission · Three-phase power · Displacement current · EM wave generation · EM wave properties