# Electronics HW question?

During the day, the ac line voltage changes. This causes the unregulated 24-V output of the power supply to vary from 21.5 to 25 V. If the zener resistance is 14 V, what is the voltage change over the foregoing range?

can you please explain the steps to solving this as I could not find an example in the book and my professor didn't explain how to do this problem

anything helps, thank you

*zener resistance = 14 ohms

### 4 Answers

- 異域秦後人Lv 71 year ago
No such term as " zener resistance is 14V " !!!!

Resistance common unit is Ohm !!

If that was your mistake to copy the question, and the zener voltage is 14V, and this is a simple zener regulator circuit. Then output from zener is equal to 14V plus or minus its tolerance percentage common is between 2% till 5%.

Variation input voltage 21.5V till 25V does not affect the 14V zener voltage output because input voltage is much much higher than 14V regulated output.

To understand zener diode, you need to hook the circuit up and do the test to provide a voltage chart, that is the best way !!!

- billrussell42Lv 71 year ago
assuming zener resistance is the equivalent series resistance for a ideal 14 volt zener.

but there has to be a resistor between the zener and the supply. Without that, this cannot be solved.

- derframLv 71 year ago
I take it you have a voltage sorce that varies from 21.5 to 25 volts, a series resistor, and a Zener diode with equivalent series R of 14 ohms. Need to know the value of the series resistor and the voltage of the Zener.