Topic: Power Electronics
Identify A and B current limiting techniques in a.c. to d.c. power supplies respectively, in the graph below. (Graph shows curve A bending back towards origin, curve B dropping vertically at Rated Current)
- A. Current limiting Mode, Constant Current Mode
- B. Re-entrant limiting Mode, Current limiting Mode
- C. Current limiting Mode, Fold back limiting Mode
- D. Fold back limiting Mode, Re-entrant limiting Mode
Answer: B. Re-entrant limiting Mode, Current limiting Mode
Explanation: Curve B drops vertically, keeping the current constant, which corresponds to Constant Current limiting mode. Curve A reduces both voltage and current simultaneously, bending back toward the origin, which is known as Foldback or Re-entrant current limiting mode.