What is Current Boosting in Voltage Regulator?

Current Boosting in Voltage Regulator – IC723 regulator is limited to provide a maximum current of 140 mA. To increase its current capacity, we add a transistor Q by connecting its collector to pin 11, base to pin 10, and emitter to pin 2, as shown in Fig. 43.38.

Thus, the collector current of transistor Q comes from unregulated dc supply. The pin 10, or say output current from V_out is into the base of the transistor, so that

Thus, the maximum current handling capacity of IC723 gets increased by factor current gain β of the connected transistor.