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#1 Sep 9, 2018
jd419
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#### Transfer characteristics of a half wave rectifier

Assuming if I were to find the transfer characteristic of the output voltage (across RL) vs input voltage (across V1) of a half-wave rectifier circuit:

How can I do it in such a way that the simulation of the transfer characteristics for the output voltage (across RL) vs input voltage (across V1) can be done from -15V to 15V for V1 over a 2-input cycle? I assumed that the x-axis variable was the input voltage, but then the 2-input cycle gives me the idea that the x-axis of the transfer characteristic graph is supposed to be frequency. Please correct me if I am wrong, and point me in the right direction. Tq.

Sun, 2018-09-09 18:07
retiredEE
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From what I've read did you run an AC analysis?  If so that would explain why the x-axis is in frequency.  Try a transient analysis with a run time of 40ms.  Change the x-axis in Probe to V1 and it wll show you the relationship of Vout as a function of V1.

Sun, 2018-09-09 21:53 (Reply to #2)
jd419
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AC Analysis? How do I do that?

I have already set the TSTOP to 40ms for the two-cycle, and have already changed the x-axis variable to V1. This is the result I get:

Why is there three lines instead of one? On further inspection,

Is this because of the 2-input cycle? Or is it because of the dead-zone voltage across the ground?

Mon, 2018-09-10 05:22
oldmouldy
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You are likely getting multiple waveforms because of the way that the simulator processes slowly changing sources, like sine waves. Try setting the Maximum Step Size to a small value, like 10u, to force the simulator to re-evaluate the simulation more frequently and improve the resolution of the results.

What you have done is correct, using Transient Analysis, and AC Analysis won't help since that provides the frequency response which is not what you need.

Tue, 2018-09-11 05:39 (Reply to #4)
jd419
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Thank you for the maximum step size suggestion! Here is the updated graph:

The graph starts to go up from 0.15V. Shouldn't the graph start going up from 0.65V-0.7V for a D1N4148 Diode?

Mon, 2018-09-10 13:05
retiredEE
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One more item: Change VAMPL to 15 to swing V1 from -15V to +15V.

Tue, 2018-09-11 05:40 (Reply to #6)
jd419
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Done, thank you. Just to clarify, we cannot use DC sweep for an AC source (VSIN). Is my understanding correct?

Fri, 2018-10-12 07:51 (Reply to #7)
Pviny
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I have  a very usefull  view on this.Iam computer analyst.About  12 years ago I found that the software is not behaving properly.I tried to find out the cause , and  came to the conclusion that first  there is  a mathematical error creeping in when we set  abnormal values or parameters and second the software is showing us  incorrect results .This is obvious  because  the actual hardware implementaion behaves diffrently.Iam myself working on correcting this.But  for  average analysis  the values would be good  to  move forward in circiut design.In other means the software is accepting only the standard values.I strongly feel this the cause for these problems.