Page 1 of 2 12 LastLast
Results 1 to 10 of 13

Thread: Polar coordinate laser oscilloscope

  1. #1
    Join Date
    Dec 2006
    Location
    Indianapolis
    Posts
    5

    Default Polar coordinate laser oscilloscope

    Im producing a Class IIIa personal laser (toy) that projects a real time polar coordinate waveform of music or sound.
    Do you think there would be a market for a version without a laser ? It would sell for $39.00
    The design would expose the 0.25 sq. mirror so you could use your own higher powered laser.
    Your thoughts, advise or questions would be appreciated.
    Best regards,

    www.musicalaser.com

  2. #2
    Join Date
    Jan 2006
    Location
    Charleston, SC
    Posts
    2,147,488,801

    Default

    Hi Curtcoffe;

    I've seen things similar to this sell on E-bay for about the price range you're talking. Though, admittedly, the units I'm speaking of use two spinning mirrors to make more random lissajous patterns. I'm assuming that you are using a single spinning mirror and one movable one (perhaps rocking on a voice coil from a gutted speaker?) to create the polar plot sound waveform effect... If so, it would be decidedly different from a lot of the lower-end consumer laser products out there, which might give you an edge.

    The video on your site is nice, though the quality is a tad low. (Badwidth restrictions?) And it takes a while to actually see what the thing is capable of... You might consider adding 10 or 15 seconds of video at the start that just shows the patterns bouncing around on the wall; that will grab the attention of the casual web surfer and hold his attention while you discuss the cable connections and the product description. Just a thought...

    However, I think most of the members here are more interested in either graphics or syncronized beam shows, and nearly everyone is already running closed-loop galvos connected to a computer. Thus, while your idea is interesting, personally I think I would tire of the effect after a while. But that's just my opinion.

    Adam

    PS: Welcome to the forum!

  3. #3
    Join Date
    Dec 2006
    Location
    Indianapolis
    Posts
    5

    Default Thanks for your feed back

    Hi Adam,

    Thanks for your thoughtful feed back.
    Your right, its a single mirror and magnet spinning in a voice coil.
    I'm taking your advise and will show it working first on the demo video.
    Looks like I need to host my own demo video. They start off having much higher quality but the Youtube compression makes them fuzzy.

    Might be interesting to make the same type display using X Y galvos.
    Something like a loop to run a (phase angle) count. Each loop you'd read the PCs sound codex input A/D and use that data for the radius.
    X = r * COS(phase angle)
    Y = r * SIN(phase angle)
    I'm sure some scaling would be needed as well.
    The phase angle would need to go from 0 to 359 degrees at about a 14 Hz rate.
    If the software loop was fast enough to get the sound input data at 1000 samples per second, it might be possiable.

    Best regards,
    Curt

  4. #4
    Join Date
    Jan 2006
    Location
    Charleston, SC
    Posts
    2,147,488,801

    Default

    You know, you might want to get together with carmangary on this project. It sounds like you and he are both headed in the same direction with regard to building a stand-alone software solution for abstract laser show patterns. (Though Carmangary's idea would also support ilda-style graphics, but only by using a separate software package to convert the ilda files to wav format first.)

    Have a look at this thread here on PhotonLexicon and see what you think.

    If you've got the programming skills to get it up and running, I don't think you'll have any problem making it work - at least from a timing point of view. The transforms you're speaking about will run several orders of magnitude faster than you need for a visual display. (If you sample at 1Khz, you'll pick up more than enough data to be able to sync the patterns to the beat.)

    Considering that most laser show software packages can only align an effect or a transition to within 1/25th of a second, your solution would be a heck of a lot more accurate than the bulk of the commerical packages out there...

    Adam

  5. #5
    Join Date
    Dec 2006
    Location
    Pflugerville, TX, USA
    Posts
    1,977

    Default

    I'm not headed in that direction at all, actually. But, I do think the laser projector in this thread is pretty cool. I can see it being useful in people's bedrooms (back in the day we had black lights and strobes in our rooms) or at night clubs that are on a low tech budget. And, it would even make a useful addition to small traveling laser shows if you could add some type of remote trigger mechanism so that the person in the booth could turn it on and off as they please.

  6. #6
    Join Date
    Jan 2006
    Location
    Charleston, SC
    Posts
    2,147,488,801

    Default

    I was speaking more in the general sense of building laser show software from scratch. I agree that the polar-coordinate idea is unique to Curtcoffee's design, but you had talked about adding an abstract generator to your waveform-playing software in that other thread.

    Maybe the two of you could cooperate on the project and combine your ideas? Just a thought...

    Adam

  7. #7
    Join Date
    Jul 2005
    Location
    Flying over a town near you
    Posts
    1,404

    Default

    You could set up the software to display f{x}....function for X variables. If you plot the graph of y=sin 2 pi T and X=2 cos pi T , assuming values of T are variable by user input , you get 2 trig curves at right angles to each other giving a lissajous figure. Maybe the software can manipulate and generate parametric equations on the fly. I am not a software designer but have a little background in math
    You are the only one that can make your dreams come true....and the only one that can stop them...A.M. Dietrich

  8. #8
    Join Date
    Jul 2005
    Location
    Flying over a town near you
    Posts
    1,404

    Default

    This was done by us a few years ago using a 25mW green and a 100mW red laser. We cheated and used the amp to directly drive a pair of laptop speakers...one for x and one for y. The red unit was on one and green on the other speaker. We attached a hinged mirror to each speaker and refleced the "sound" off of the two combined beams creating some really strange patterns.......I will try and locate it and post a pic or 2. You could'nt hear the music...but you could see it.
    You are the only one that can make your dreams come true....and the only one that can stop them...A.M. Dietrich

  9. #9
    Join Date
    Dec 2006
    Location
    denver,co
    Posts
    1,078

    Default

    Most old school analog synths can reproduce this effect, some also had an audio in for the extra modulation. It it still a neat little gizmo. I saw patent pending. Are you planning on patenting it? If it were me i wouldn't bother. Chances are that in the people in the usa will not copy it and try to reproduce it. If it is copied it will probably be from the Chinese and they can build it for 1/10 of what it costs you and food the market with them. Look at what happened with Cambridge. I would take the money you would spend on a patent and pump it into advertising and get what you can while you can.

    Just my .02c

    But good luck!


    Chad

  10. #10
    Join Date
    Dec 2006
    Location
    Indianapolis
    Posts
    5

    Default Good feedback

    Hi All,
    Thanks for the great feedback! OK, now my interest is peaked on discovering if an XY galvo set can reproduce this effect or not.
    Not wanting to spend lots of $ on galvos, I've ordered the 15kpps SCANECO15 from aijii on eBay to try out some hardware and software ideas.
    I can also use the XY galvos to project my URL text while marketing the musicalaser in public
    I'm going to try Chad's idea which is based on an old analog keyboard syth VCA voltage controlled amplifier circuit.
    A variable frequency opamp SIN oscillator feeds an opamp 90 degree phase shifter to produce COSIN.
    The SIN and COSIN signals will be individually feed into separate VCAs made from CA3080s transconductance amplifiers. The control voltage input will be the music source. One VCA output will feed galvo amp X, the other feeds Y. Throw in some offset and gain scaling where needed and it should work. Hope to have it done over the holidays. I have a micro CNC router that machines printed circuit boards and just finished making a PCB of a simple two channel DAC using two DAC0832 chips that bolts up to a PC printer port for software control. I'm sure you've seen the circuit before, found it on Norm's Homemade laser show page. I changed his single ended opamp outputs to differential outputs. I'll post a link to the gerber and pdf files after I test it this weekend.

    Chad, I've already applied for a patent. It really wasn't that expensive as I did all the patent application work using TurboCAD and a piece of software called "Patent Now", though I did have a lawyer write the claims. I've been to China twice to source a contract manufacture and have them waiting in the wings, also have VC money, just need to land that big fish, Wal-Mart?. One of the problems in selling a gob of these is that your average Joe consumer does not know what it is. A retailer buys the first batch and they don't sell then you're done. It becomes a one shot sell, so I'm starting to try ways of taking it to the people I.E. marketing.

    This laser stuff is fun. Have a great holiday.

    Best Regards,

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •