Quick Recap — Rectifiers, Special Diodes & Logic Gates
- Rectifiers: convert AC to DC. A half-wave rectifier's ripple frequency equals the input frequency; a full-wave (or bridge, 4 diodes) rectifier gives ripple at twice the input frequency. A capacitor filter smooths the output.
- Zener diode: operated in reverse breakdown at a constant voltage — used as a voltage regulator.
- Special diodes: LED emits light in forward bias; a photodiode (reverse biased) and solar cell respond to light.
- Logic gates: AND (1 only if all inputs 1), OR (1 if any input 1), NOT (inverter); NAND and NOR are universal gates.
Worked mini-example. A full-wave rectifier fed with 50 Hz mains produces a ripple whose fundamental frequency is Hz.