Figure below shows a simple power circuit diagram of a three phase bridge inverter using six thyristors and diodes. A careful observation of the above circuit diagram reveals that power circuit of a three phase bridge inverter is equivalent to three half bridge inverters arranged side by side. The three phase load. There are two possible patterns of gating the thyristors. In one pattern, each thyristor conducts for 180° and in other, each thyristor. RMS value of Line voltage VLis given as below. VL = 0.8165Vs RMS Value of phase voltage Vpis given as below: Vp = 0.4714Vs RMS value.