How many diodes are required for a three-phase bridge rectifier circuit 2

In a bridge rectifier circuit, three phases of alternating current are connected to the three phase input terminals of the bridge, while the load resistor is connected to the output terminal of the bridge. When the A phase of AC power is in the positive half cycle, the B and C phases are in the negative half cycle, respectively. At this point, the diode at the A-phase input terminal will operate, and current will flow through it to the load resistor. The diodes at the input terminals of phases B and C are in a conducting and closed state, and no current flows through them. When the B phase of AC power is in the positive half cycle, the A and C phases are in the negative half cycle, respectively. At this point, the diode at the B-phase input will operate, and current will flow through it to the load resistor. The diodes at the input terminals of phases A and C are in a conducting and off state. The same principle also applies to phase C.diode

Through this working method, the bridge rectifier circuit can rectify alternating current, converting it into direct current. In each half cycle, only one phase of current can flow through the load resistor, and its direction is consistent with the direction of the alternating current. In this way, the direction of the current can be switched between the positive and negative half cycles, forming a stable DC power supply.diode

So let's discuss why a bridge rectifier circuit requires four diodes. We need to understand the following aspects:

1. Bipolar voltage and unipolar voltage: AC power is a type of bipolar voltage, where the polarity of the voltage constantly changes between positive and negative. Direct current is a unipolar voltage, and the polarity of the voltage is fixed. Therefore, the process of rectification is to convert bipolar alternating current into unipolar direct current.diode