## NdeveR 3 years ago 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

1. NdeveR

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.

2. NdeveR

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.

3. nick67

|dw:1348666679433:dw|

4. nick67

|dw:1348667042917:dw|

5. nick67

|dw:1348667163811:dw|

6. nick67

|dw:1348667507556:dw|

7. Sparkle

What about the last bit, minimum value of RL..Im getting it wrong.

8. nick67

@Sparkle could you better explain your problem, pls :-)

9. dany

Teh minimum value of RL is the value of RL when the voltage across the RL is equal to that of Vz

10. yahya.aamir

@nick67, I tried looking at the your explanation. But couldn't figure out the answer when the Zener diode is implemented. Could you please explain it again?

11. nick67

@yahya.aamir Hi, you should separate DC and AC analysis, this way: |dw:1349534424806:dw|

12. nick67

|dw:1349534977332:dw|

13. yahya.aamir

Thanks @nick67. I really appreciate it. :-)

14. nick67

you're welcome

15. mahi1431

hey plz explain me clearly

16. nick67

@Nurali could you post the question in a separate post ? I'm quite sure that Stefo should be very interested, too; he has big knowledge about FETs

17. ammanjordan

Can we have the results as results (Numbers)?

18. nick67

@ammanjordan from http://openstudy.com/code-of-conduct : Give Help, Not Answers I will encourage and guide those needing help, and not just give them an answer

19. ammanjordan

Thank nick67, solving the problem, i found the value of Vo for RL=ΚΩ, also, i found the same Vo when RL = 4ΚΩ. How i can find the relevants u0 when RL=2 and 4 ΚΩ?

20. ammanjordan

Hi guys, can i have some method to find vo for RL= 2 and 4 ΚΩ. thanks.