Half-Wave Rectification

RECTIFICATION

Is the process which an alternating current is formed to only flow in one direction. Rectification is done by using of diodes.

OR

Rectification is the process of converting alternating current to pulsating direct current.

WAYS OF RECTIFICATION

There are two ways of rectification

                     i.            Half wave rectification.

                   ii.            Full wave rectification.

HALF WAVE RECTIFICATION

Is the rectifier that yields diode out during the positive half cycle of the a.c input.

OR

Half wave rectifier is a simple circuit where a.c is applied to a diode and a resistor connected in series such that current flows through the resistor only when the diode is forward biased.

OPERATION

The A.C Voltage across the secondary winding AB changes polarities after every half – cycle.

During the positive half cycle of the sinusoidal Wave Terminal A is positive and B is negative. The diode become forward biased hence current flows in the load resistance (R_L).

During the second half cycle terminal A is negative and B is positive. The diode becomes reverse biased and no current flow in the load resistance (R_L).

Note:-

In half wave rectifier when diode is connected with only resistor the voltage (output) is not steady and needs to be smoothed for it to be used. 

SMOOTHING

Is the process of maintaining steady voltage in half – wave rectifier by connecting large capacitor in a parallel with the load.

The capacitor C is charged in the positive half Cycle and discharges to a load R_L in the negative half Cycle.

DISADVANTAGE OF HALF WAVE RECTIFIER

1. The a.c supply delivers power a half the times hence output is low (Low efficiency)
2. It needs smoothing capacitor to be added in the circuit.

Note:-

                        i.            A rectifier is an instrument that converts a.c to d.c

                      ii.            An inverter is an electric device that convert d.c to a.c