A student wishes to use the circuit of Fig. P1.91 to design a 15-V voltage reference capable of supplying a maximum load current (IL and RL combined ) of 25 mA. The Zener diode D2 has rz 5 10 V and VZ...

A student wishes to use the circuit of Fig. P1.91 to design a 15-V voltage reference capable of supplying a maximum load current (IL and RL combined ) of 25 mA. The Zener diode D2 has rz 5 10 V and VZ 5 15 V at IZ 5 25 mA, and the rectifi er diode D1 has VD(on) 5 0.8 V. (a) Make educated decisions to specify the transformer’s turns ratio n, the capacitance C, the series resistance R, and the rectifi er diode D1 (iD(max), iD(avg), and PIV). (b) What is the amount of ripple across the load?