Q. A shunt regulator uses a zener diode whose voltage is 5.1V at a current of 50ma and whose incremental resistance is 7W. The diode is given with a supply of 15 V nominal voltage by a 200 W resistor. Determine the output voltage at no load? Find out the line regulation and load regulation.

Solution:

                                                                V_zo=5.1-7(50m)

                                                                       =4.75V

                                During no load condition

                                                                V_o= (15-4.75)7/207+4.75

                                                                    =5.1V

                                                Line regulation=r_z/(R+r_z)

                                                                         =7/207=33.8mV/V

                                Load Regulation= - (r_z||R)

                                                                                = -(7||200)

                                                                                = - 6.8W

                                                                                = -6.8mV/mA