This type of chopper is obtained by connecting type-A and type-B choppers in parallel as shown in Fig.1.a. The putput voltage $V_{0}$ is always positive because of the presence of freewheeling diode $FD$ across the load.

When chopper $\mathrm{CH} 2$ is on, or freewheeling diode $\mathrm{FD}$ conducts, output voltage $v_{0}=0$ and in case chopper $\mathrm{CH} 1$ is on or diode $\mathrm{D} 2$ conducts, output voltage $v_{0}=V_{s}$ . The load current $i_{0}$ can, however, reverse its direction. Current $i_{0}$ flows in the arrow direction marked in Fig. 1.a, i.e. load current is positive when $\mathrm{CH} 1$ is on or$FD$ conducts. Load current is negative if $\mathrm{CH} 2$ is on or $D2$ conducts. In other words, $CH1$ and $FD$ operate together as type-A chopper in first quadrant. Likewise, $\mathrm{CH} 2$ and $D2$ operate together as type-B chopper in second quadrant.

Average load voltage is always positive but average load current may be positive of negative as explained above. Therefore, power flow may be from source to load or from load to source. Choppers $\mathrm{CH} 1$ and $\mathrm{CH} 2$ should not be on simultaneously as this would lead to a direct short circuit on the supply lines. This,type of chopper configuration is used for motoring and regenerative braking of dc motors. The operating region of this type of chopper is shown in Fig.1.b by hatched area in first and second quadrants.