Rectifiers and Filters

Group 1Abucejo

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RectificationBasic Definition: Rectification is

the conversion of an alternating current (AC) to a direct current (DC). This is done by using a device that allows only a one-way current, like a diode.

Kinds of Rectification1. Half-waveII. Full-wave

I. Half-WaveHalf-wave rectification is a

simpler and easier way of converting your AC to DC.

It is called a half-way circuit, because you only allow half of the AC cycle to pass, thus having only used half its capacity.

Recall:

Half-Wave graph

II. Full-waveA more common and efficient

approach to convert AC current to DC current is by manipulating the AC wave such that all of it is used.

-When polyphase AC is rectified, the phase-shifted pulses overlap each other to produce a DC output that is much “smoother”

Polyphase full-wave bridge design

Summary

Half-wave rectifierUses only positive part of the

sine graphEasier to make but more

inefficient

Full-wave rectifierUses all parts of the sine

graph(converts the negative to positive)

More efficient, more commonly used

FilterA filter is an AC circuit that

separates some frequencies from others within mixed-frequency signals.

Audio equalizers and crossover networks are two well-known applications of filter circuits.

Low-passa low-pass filter is a circuit

offering easy passage to low-frequency signals and difficult passage to high-frequency signals

2 Kinds:1. Inductive low-pass2. Capacitive low-pass

Inductive low-pass

Capacitive low-pass

High-passA high-pass filter's task is just the

opposite of a low-pass filter: to offer easy passage of a high-frequency signal and difficult passage to a low-frequency signal.

2 Kinds1. Inductive high-pass2. Capacitive high-pass

Inductive high-pass

Capacitive high-pass

SummaryLow-pass

High

Low

SummaryHigh-pass

High

Low