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For the series regulator shown in Figure 9.2, assume that RL = 32, Vz = 10V, and for the BJTs, B = 100 and VBE = 0.7V. (a) Calculate the power efficiency of the regulator. (Hint: Express VL in terms of VZ and other components in the circuit. Verify the assumptions made in deriving VL). (b) The Zener diode voltage thermal coefficient is +3mV/K and the base-emitter voltage thermal coefficient is -2mV/K. Assuming that the Zener diode and base-emitter voltages as well as their thermal voltages have negligible change with their existing operating currents. Calculate the thermal coefficient of the output voltage.

For the series regulator shown in Figure 9.2, assume that RL = 32, Vz = 10V, and for the BJTs, B = 100 and VBE = 0.7V. (a) Calculate the power efficiency of the regulator. (Hint: Express VL in terms of VZ and other components in the circuit. Verify the assumptions made in deriving VL). (b) The Zener diode voltage thermal coefficient is +3mV/K and the base-emitter voltage thermal coefficient is -2mV/K. Assuming that the Zener diode and base-emitter voltages as well as their thermal voltages have negligible change with their existing operating currents. Calculate the thermal coefficient of the output voltage.

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For the series regulator shown in Figure 9.2, assume that RL = 32, Vz = 10V, and for the BJTs, B = 100 and VBE = 0.7V. (a) Calculate the power efficiency of the regulator. (Hint: Express VL in terms of VZ and other components in the circuit. Verify the assumptions made in deriving VL). (b) The Zener diode voltage thermal coefficient is +3mV/K and the base-emitter voltage thermal coefficient is -2mV/K. Assuming that the Zener diode and base-emitter voltages as well as their thermal voltages have negligible change with their existing operating currents. Calculate the thermal coefficient of the output voltage.

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