D *4.64 It is required to design a zener shunt regulator to provide a regulated voltage of about 10 V. The available 10-V, 1-W zener of type 1N4740 is specified to have a 10-V drop at a test current of 25 mA. At this current, its rz is 7 Ω. The raw supply, VS, available has a nominal value of 20 V but can vary by as much as ±25%. The regulator is required to supply a load current of 0 mA to 20 mA. Design for a minimum zener current of 5 mA.
(a) Find VZ0.
(b) Calculate the required value of R.
(c) Find the line regulation. What is the change in VO expressed as a percentage, corresponding to the ±25% change in VS?
(d) Find the load regulation. By what percentage does VO change from the no-load to the full-load condition?
(e) What is the maximum current that the zener in your design is required to conduct? What is the zener power dissipation under this condition?
(a) 9.825 V; (b) 207 Ω; (c) 33 mV/V; ± 1.65%; (d) −6.77 V/A; −1.35%; (e) 70.9 mA; 732 mW