Rectification

AC to DC Electricity distribution –Power stations –Transformers –Transmission lines AC Electronics DC –Smooth –Stable

Process of rectification Conversion of AC to DC Half-wave Full-wave Dedicated circuits –Contain diodes Semiconductor Thermionic –Power rating Supply current to circuits

Half-wave rectification Only the positive half- cycle of the AC supply is allowed to pass

Half-wave rectifier circuit Simple! Single diode ‘Load’ –DC circuit…not really getting DC! V ac Load

Full-wave rectification Positive AND negative half-cycles converted to ALL positive

V ac Load Full-wave rectifier circuit Bridge circuit Load –Circuit requiring DC

Bridge as two potential dividers V out V ac

Capacitative smoothing V out V ac

Smoothed output Un-smoothed –Large ripple voltage –Not true DC Low-value smoothing capacitor –R load C small High-value smoothing capacitor –R load C big

for... Capacitors Rectification PSU Electronic power supplies Bridge rectifiers