Rectifier

Rectifiers are use for converting AC into DC by means of  semiconductor components called diodes. The circuit is use for allowing current to flow in one direction.

Rectifiers are made of diodes connected together in series to one another. Diodes allows current to flow in only one direction. Electrons can only flow through a diode from it cathode to anode, while current can only flow from the anode of a diode to  the cathode. That means current applied to a diode in opposite direction is blocked completely from flowing. How do diodes rectify currents and DC from AC.

Types of rectifier circuits.

1. Half wave rectifier.

An half wave rectifier is a type of rectifier that only allows an half-cycle of an AC voltage waveform to pass, blocking the other half-cycle. 

The half wave rectifier is use to allow current to flow in one direction. Its use to filter or rectify out DC from AC. The rectified DC isn't as pure as that obtained from batteries, because it contains ripples and unsteady direct current.

The half wave rectifier contains only one diode.

Applications of  an half wave rectifier.

The half wave rectifier circuit is the simplest form of rectifier circuit that can be used, and although it may not provide the highest level of performance in some aspects, it's nevertheless very widely used.

| Power rectification.

One more the most obvious ways for a half wave diode rectifier to be used is within a power rectifier. A line or mains power input normally passes through a transformer to transform the voltage to the required level.

|AM demodulation.

When the half wave rectifier is used for amplitude modulation detection, the circuit obviously requires to interface to the other circuits in the radio. 

|Peak detector.

The half wave diode circuit is often used as a simple voltage peak detector. By placing a capacitor across the output load, the capacitor will charge to the peak voltage ( &SQRT; 2× RMS voltage of a sine wave). Provided the time constant of CR network, capacitor and load resistance is much longer than the period of the waveform or sufficient to capture the peak of a varying waveform the circuit will hold the peak voltage. The transformer provides isolation from the maibs or line power and also enables the input voltage to the diode to be at the required level. Note that the peak voltage is equal to &SQRT;2 or 1.414 times the RMS value.

2. Full wave rectifier.