Question

H4P1: Zener Regulator
A non-ideal voltage source can be modeled by a series combination of an ideal DC voltage source, a resistance, and a small-signal voltage source. The small-signal source is included to represent the noise inherent in the source. This model is illustrated in the figure below:

In practice, connecting the non-ideal voltage source to a load may result in undesirable effects due to the noise voltage vo appearing across the load.

This problem studies such effects and how a Zener diode may be used to ameliorate the problem.

Assume that VI=13.0V, RIN=1kΩ, and vi=20.0m

Answer 1

there is more to this problem: and here are some pictures

Again, we calculate vo (i.e. output noise) and VO (i.e. DC output voltage) for RL=2kΩ and RL=4kΩ for this new circuit.

Hint: Your first job here is to determine which of the three regions of the piecewise-linear characteristic of the Zener is the one containing the operating point: we suggest you sketch a load line, but be very careful about the signs. Once you have determined where the operating point is, you can model the Zener in the circuit with a series combination of an independent voltage source and a resistor.

Answer 2

so far, i have only been able to solve for RL=2kohm, Vo is 8.6667 volts. if anyone could explain this one i'd appreciate it.