Please help me to produce a particular Lissajous pattern in Cathode ray Oscilloscope

Sep 03, 2009 5 Replies

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Ravi 16 years ago

I have to implement a particular Lissajous pattern in C.R.O.The lissajous pattern is elliptical in shape (ie pattern due to some phase difference) and it should be moving in a circular path like a coin is tossed.ie the coin should move like a flipping coin(about an axis) in a circular path (that should be repeatable). there are several hint for this:

1) A dual Supply will be provided
2) programmable ICs are not permitted
3) XY mode
4) Only sinusoidals are used

Video and details are given in this link:

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Paul E. Schoen 16 years ago

Sounds like "ohmwork"

Paul

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George Herold 16 years ago

OK here's another hint, you can just make a circle on the XY scope by feeding a sine to the X axis and the cosine (90 degree phase shift of sine) to Y-axis. Make the ellipse flat or tall by changing amplitudes... make it squish along axis at 45 degrees to X-Y by changing relative phase.

Now it's your turn to add the coin bit.

George H.

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Rich Grise 16 years ago

Two oscillators.

Now, go read your textbook and do your own damn homework.

Good Luck! Rich

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Phil Allison 16 years ago

"Ravi"

** Requires 3 sine wave oscillators - one at a very low frequency like 0.25 Hz, the other two close in frequency at a few hundred Hz and with fine frequency adjustment.

A variable phase shift network for the low oscillator and two summing stages to produce the final X and Y signals.

All the sine waves could be derived by low pass filtering square waves.

Simple really.

..... Phil

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David Eather 16 years ago

Nah, he is posting on other news groups asking the same question. I suggest only supplying him wrong information.

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