# zener diode lab problem ???

Discussion in 'Homework Help' started by lightin, Mar 9, 2014.

Mar 9, 2014
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2. ### WBahn Moderator

Mar 31, 2012
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Well, sketch what you think the waveform will look like for the two input waveforms and then we will have something to discuss.

3. ### lightin Thread Starter New Member

Mar 9, 2014
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for Vin = 5V p-p , nothing is passing through the zener
At Vin= 10Vp-p, half sine wave ( negative part ) appears,

4. ### lightin Thread Starter New Member

Mar 9, 2014
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and the answer is no it won't change
is it right ???

5. ### WBahn Moderator

Mar 31, 2012
17,777
4,805
Think about that. Let's just take your claims about the waveforms at face value.

Case 1: Nothing appears.

Case 2: A half-sine wave appears.

Claim: Case 1 and Case 2 have the same shape.

Do YOU buy that claim?

As for whether your claims about the two output waveforms is correct, you need to sketch what you think they will be. Then we can talk about specific things in your sketch that may or may not be correct in a meaningful way.

Mar 9, 2014
4
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7. ### WBahn Moderator

Mar 31, 2012
17,777
4,805
What will help you a lot is if you prepare a DC transfer characteristic. This is very simple and straightforward. On the horizontal axis you plot an input voltage -- in your case, make it go from -10V to +10V since that is the range you are interested in. On the horizontal axis you plot the corresponding output voltage.

The plot should consist of just a few straight line segments. Off the top of my head I think it should be three -- one for when the zener is forward-biased and conducting, one for when the zener is non-conducting, and one for when the zener is reverse-biased and conducting.

With that chart in hand, you can very readily plot the output waveform for an input waveform.