Single-Phase Full-wave Rectifier

In full wave rectifier both the both half-cycles of the input are utilized with the help of two or four diode working alternately. For full-wave rectification, use of the transformer is essential (through it is optional for half-wave rectification).

Single-Phase Centre-Tap Full-wave rectifier

The full-wave rectifier circuit using two diodes and a centre-tapped transformer shown in Figure 1-1. The centre-tap is usually taken as the ground or zero voltage reference point.

Working

When input ac supply is switched on, the ends M and N of the transformer secondary become +ve and -ve alternately. During the positive half-cycle of the ac input, terminal M is +ve, G is at zero potential and N is at –ve potential. Hence, being forward-biased, diode D1 conducts (but not D2 which is reversed-biased) and current flows along MD1CABG. As a result, positive half-cycle of the voltage appears across RL.

During the negative half-cycle, when the terminal N becomes +ve, then D2 conducts (but not D1) and current flows along ND2CABG. So, we find that the current keeps on flowing through RL in the same direction (i.e. from A to B) in both half-cycles of ac input. It means that both half-cycles of the input ac supply are utilized as shown in figure 1-2. Also, the frequency of the rectified output voltage is twice the supply frequency. Of course, this rectified output consists of a dc component and many ac components of diminishing amplitudes.

One thought on “Single-Phase Full-wave Rectifier”

1. Nidal says:

Hello!! just tried this circuit and the freq output about 100 HZ why is this happen ?? thanks