Preparation;
In a half-wave rectifier, as shown in Figure 4-1 , a load resistance (Rl) is connected to an ac source
through a single diode. When the input sine wave is positive , the diode is forward-biased and allows
current to flow in the load resistance. When the input sine wave is negative, the diode is reverse-biased
and prevents current flow in the load resistance. Therefore, only the positive half of the sine wave
voltage is across the load resistance , and the voltage across the load resistance is zero during the
negative half of the input sine wave. This produces a pulsating dc voltage across the load resistance.
The average value of this pulsating half-wave rectified output voltage (V dc) is the value measured by a
dc voltmeter, and is calculated by dividing the peak output voltage (V p) by π. Therefore.
V dc=(V p )/( π)
The diode barrier potential, or forward-bias voltage (V f = 0.7V), causes the peak of the output to be
less than the peak of the input wave. This happens because the output voltage is equal to the input
voltage minus the voltage drop across the diode