Question

Explain two-quadrant chopper.........

Answer 1

Two quadrant chopper:

 There are two semiconductor controllable switches in the two-quadrant chopper.

Two quadrant type A chopper:

The figure shows the type A chopper. Both the switch never turn on at the same time because this will cause a short circuit. At the output, there is a freewheeling diode so the voltage is always positive. When the chopper 2 (or switch 2) is turned on then the voltage is zero and when chopper 1 is turn on then the output voltage V_o=V_s.

Two quadrant type B chopper:

The figure shows the two quadrant type B chopper. In this type of chopper, current is always positive. When both chopper 1 and chopper 2 are turned on then V_o=V_s. When chopper 1 and chopper 2 are off then V_o=-Vs.