Lissajou - possible with ??? - Page 1
Forum section: electronics / general

author: TrabanT
author_rank: Newbie
timestamp: November 03, 2014, 08:30:57 pm
content: hi guys,I just started messing with oscilloscopes and the Lissajous patterns ... got it to work for like 2 hours, then my PM3231 broke,,,this is what I came up withnow I am hooked and want to know ... which OSC is good for these patterns?will 2 axis be enough if you can phase shift them ... how does one know that without reading every manual?thanks for all info!

author: atferrari
author_rank: Frequent Contributor
timestamp: November 03, 2014, 10:11:20 pm
content: Quote from: TrabanT on November 03, 2014, 08:30:57 pmAnyone that works?

author: SL4P
author_rank: Super Contributor
timestamp: November 03, 2014, 10:17:59 pm
content: Try other waveforms - not just triangle and modulated.Also play with external triggering with a divider connected to your oscillators.The patterns will stand still (or not), and offer a million more visual variations.Welcome to the seventies.

author: TrabanT
author_rank: Newbie
timestamp: November 03, 2014, 10:25:18 pm
content: thanks for your answer SL4P ---i dont know if you are familiar with Elektron Analog 4 ... it has several wave forms. ... also today, just before my OSZ killed itself , I was using the Monomachine also a Elektron Toy, it has a wavetable with sooo many waveforms...hmmm...your idea with the external triggering is great... i didnt know it could be used in such a way....... what exactly do you mean by "dividers" ?would you please elaborate...and now to my most sincere question:except for "it must have X Y mode" how do I recognize a good Scope which will not let me down ? Could you provide me with a specific model, preferably few models? =? that would be really helpfulshould I go for analog (or would digital also do it)big thanks for all info!!!

author: German_EE
author_rank: Super Contributor
timestamp: November 03, 2014, 10:31:19 pm
content: The seventies would be just about right, that was when I discovered an old Heathkit scope in the Physics lab at school (and the rest is history). What you are looking at is the phase difference between the signals on the X and Y plates of the scope so here are some more things you can try:1) Different combinations of waveform, two square waves will for example trace out the sides of a square on the screen as they interact. Sawtooth waveforms don't work too well though because then you just have a conventional scope2) Comparing two frequencies. If the two frequencies have a harmonic relationship then the pattern will be still and this is a great way of comparing frequency differences. If your pattern rotates once a second then you have a 1Hz difference between your two signals.3) Phasing effects in music show up really well if you feed the left channel into the X input and the right channel into the Y input.4) Finally, the advanced stuff.O0

author: TrabanT
author_rank: Newbie
timestamp: November 03, 2014, 10:45:43 pm
content: 1) Different combinations of waveform, two square waves will for example trace out the sides of a square on the screen as they interact. Sawtooth waveforms don't work too well though because then you just have a conventional scope2) Comparing two frequencies. If the two frequencies have a harmonic relationship then the pattern will be still and this is a great way of comparing frequency differences. If your pattern rotates once a second then you have a 1Hz difference between your two signals.3) Phasing effects in music show up really well if you feed the left channel into the X input and the right channel into the Y input.4) Finally, the advanced stuff.O0hey, thanks for answer ....1) more frequencies the better... was in my first 2 hours.... will keep it in mind!2)will get into the math part maybe in a few weeks or month ...3)yeah the X and Y thing is the key to trippy shit!4)i dont really like the idea of prefabricated waves... I like the rough original view... thanks for the video however!another question;would Tektronix Type 502A work good?are you from around berlin?

author: AG6QR
author_rank: Frequent Contributor
timestamp: November 03, 2014, 11:29:03 pm
content: Quote from: TrabanT on November 03, 2014, 10:25:18 pmThis is one area where analog works better than digital. Virtually any analog scope with an X-Y mode will do a fine job. Many digital scopes don't do nearly as well.An analog scope keeps the beam turned on continuously. A digital scope samples for a while, then transfers its samples into video memory. It has some "blind time" between sampling. The extent of this issue varies from one scope to another, but it's pretty awful on entry-level digital scopes like the Rigol DS1052E. And it's not great even on some scopes that are considerably better than that entry-level Rigol.But any analog scope with an X-Y mode does the job very well, subject to the bandwidth limits.I haven't used a Tek 502A that you mention, but looking at the manual, it has an X-Y mode and seems well suited to the task.

author: westfw
author_rank: Super Contributor
timestamp: November 04, 2014, 05:27:52 am
content: November 1975 issue of "Popular Electronics" featured this scope pattern generator:https://www.acc.umu.se/~polarn-p/sas/Video/ScopeArt.pdf

author: TrabanT
author_rank: Newbie
timestamp: November 04, 2014, 07:18:36 am
content: Quote from: AG6QR on November 03, 2014, 11:29:03 pmthanks for your answer and for looking up the XY mode ! ! ! ... analog for the win!

author: TrabanT
author_rank: Newbie
timestamp: November 04, 2014, 07:20:43 am
content: Quote from: westfw on November 04, 2014, 05:27:52 amhey, thank you for this info! ... that is surely a nice toy ... however I would like to keep generating patterns from sounds I make with my synthesizers ... so it would be esthetically pleasing to the eye and the ear ...

author: GK
author_rank: Super Contributor
timestamp: November 04, 2014, 11:20:41 am
content: Lissajous curves are ultimately a bit boring in comparison to chaotic attractors. For example:http://www.glensstuff.com/sprottsystems/sprottsystems.htm

author: kc0ngu
author_rank: Contributor
timestamp: November 06, 2014, 01:47:16 am
content: Quote from: TrabanT on November 04, 2014, 07:20:43 amIf I understand correctly this circuit (and those like it) can accept a sound input to translate sounds into patterns.Just a thought.

author: TrabanT
author_rank: Newbie
timestamp: November 06, 2014, 02:38:28 pm
content: hey, thank you for this info! ... that is surely a nice toy ... however I would like to keep generating patterns from sounds I make with my synthesizers ... so it would be esthetically pleasing to the eye and the ear ...If I understand correctly this circuit (and those like it) can accept a sound input to translate sounds into patterns.Just a thought.... well that would be pretty sweet and sure a welcome addition to my synthesizer freuquencies ... I am only 5 hours into Oscilloscopes ...i am also not into soldering and a pretty bad craftsman ... where can I buy such a fun toy? anybody selling these? anybody willing to make one for me?cheers and thanks for reply!

author: Bassman59
author_rank: Super Contributor
timestamp: November 07, 2014, 03:15:00 am
content: Have you ever noticed that every movie or TV show that has scenes in a laboratory always has an oscilloscope displaying lissajous figures in the background? (Bonus: sometimes the oscilloscopes don't have anything connected to their inputs!)With that in mind, I took one of the Silicon Labs 8051 boards that were lying around and programmed it to output the lissajous figures on its two DACs, and connected the DAC outputs to the oldest, ugliest analog 'scope we had in the office. Every few seconds it chooses a new pattern. The only downside is that the 'scope's fan is annoyingly loud. But now my desk looks like Hollywood's vision of an engineering bench.

author: TrabanT
author_rank: Newbie
timestamp: November 07, 2014, 07:21:52 am
content: Have you ever noticed that every movie or TV show that has scenes in a laboratory always has an oscilloscope displaying lissajous figures in the background? (Bonus: sometimes the oscilloscopes don't have anything connected to their inputs!)With that in mind, I took one of the Silicon Labs 8051 boards that were lying around and programmed it to output the lissajous figures on its two DACs, and connected the DAC outputs to the oldest, ugliest analog 'scope we had in the office. Every few seconds it chooses a new pattern. The only downside is that the 'scope's fan is annoyingly loud. But now my desk looks like Hollywood's vision of an engineering bench.... hi ... googled that board, nothing came up... but I have to say I am so not into electronics, just like 6 hours into scopes ... would sure like to see a picture of your setup ... anyways, could you solder one of these 3d scope imaging things for me metioned above? ---- thanks for reply buddy