AD633 analog multiplier IC and AM generation.

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Discussion Overview

The discussion revolves around the use of the AD633 analog multiplier IC for generating amplitude modulation (AM) waves. Participants are exploring issues related to circuit performance, output waveforms, and potential errors in the setup.

Discussion Character

  • Technical explanation
  • Debate/contested
  • Experimental/applied

Main Points Raised

  • One participant, Devanand T, reports incorrect output when using the AD633 circuit for AM wave generation and seeks explanations for the error.
  • Another participant suggests that the issue may stem from the simulation software used to visualize the output, implying that the observed waveform anomalies could be due to software defects.
  • A different participant points out a potential issue with the connections to the AD633, specifically regarding the "Y" input not being properly connected.
  • Devanand T clarifies that they are not using simulation software and that the output was reproduced from a real CRO (cathode ray oscilloscope).
  • One participant notes that the waveform appears to show modulation superimposed on the carrier rather than proper modulation, suggesting a check on the connections to Y1 and Y2.
  • Another participant describes an observation where the output waveform appears misaligned, indicating a possible issue with the measurement device or settings.
  • One suggestion involves troubleshooting by setting the modulation input to zero to verify if the carrier signal is being processed correctly.
  • Devanand T asserts that the circuit diagram itself has no errors.

Areas of Agreement / Disagreement

Participants express differing views on the source of the problem, with some attributing it to potential connection issues or measurement device malfunctions, while others suggest software-related problems. The discussion remains unresolved with multiple competing perspectives on the cause of the incorrect output.

Contextual Notes

There are indications of missing assumptions regarding the setup and connections, as well as potential dependencies on the specific measurement devices used. The discussion does not resolve these uncertainties.

dexterdev
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Hi PF,
I used the circuit shown in datasheet of AD633 to generate AM waves. But the output I got was not correct. I want to why this error comes and explanations will be helpful. I will have to go for BF194 designs else. Here in our labs transistor circuits seldom works. Why I don't know? Please help. I am attaching the circuit and o/p waves.

TIA

-Devanand T
 

Attachments

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Engineering news on Phys.org
This looks like a problem in whatever you're using to simulate a scope.. signals don't just 'end' like that, jump to the side, resume, end again, and jump back. Defective scope software does though.
 
Looks like your "Y" input is not making it into the AD633. Check connections to pins 3 and 4.
 
I am not using any simulation s/w, this is the cro o/p I reproduced by drawing...
 
The waveform looks like modulation is superimposed (added to) carrier instead of modulating the carrier. This will happen if the carrier is making it into Z but not into Y1. Check your Y1,Y2 connection.

What frequency are you at?
 
The picture that appears on my screen shows bottom half of measured output wave shifted right by about seven carrier cycles.
If i shift it left to where it aligns, i see a wave that looks just like "expected".

I would diagnose that as a computer software malfunction or misadjustment.

What kind of device are you using to capture that wave?

I dislike computerized oscilloscopes for basic work.
 
I cut copy shifted the image of wave to resemble the wave I got in real CRO...It is not a software generated output.
 
What emi guy said...


well, get it working one piece at a time.

Set Em to zero and see if carrier Ec is making it through...

then try very small increments of Em,

is what i'd do.
 
will try...
 
  • #10
the circuit diagram has no error.
 

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