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Thread: Back then...this is what we did...

  1. #11
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    Quote Originally Posted by kecked View Post
    Great thread. I saw laserium in 1975 as a 9 year old in cleveland. I’m still here. Few move moving experiences in my life.
    Thanks kecked. I saw laserium the first time in Denver in 1976 and a second time in OKC in 1977 at 28 years old. Seeing visuals set to music became my favorite thing, and having a background in music, art and audio made it a perfect fit for me.

    Using the 4 XR2206 waveform generators in a phase-locked-loop configuration really opened my eyes for how two XY sine waves with integer harmonic relationships, with specific phase angle differences, combine to form visual harmonies.

    When discussing harmonics, there must be a reference frequency that we use as the 1st harmonic. Further, lets limit the harmonic range from the 1st to the 10th harmonic. Lets set the 1st harmonic to be 50 Hz, send one phase version of this harmonic to the X axis scanner and another 1st harmonic to the the Y axis 1st harmonic that is exactly 90 degrees out of phase with the X axis 1st harmonic. The scanned image will be a perfect circle. (With a phase-locked-loop oscillator, its phase angle can be set by a 10-turn potentiometer to any desired angle between 0 and 360 degrees and it will lock on that phase angle. If the X and Y signal amplitudes are identical, the scanners will "draw" a perfect circle, 50 times per second.

    Now lets add another independent PLL XY signal pair that can be "added" to the 1st XY signal pair such that the 2 X signals are added together and the 2 Y signals are added together to form a single composite XY signal. This is where it gets very rewarding and the harmonic math is quite simple. And lets limit our 2 XY signal amplitudes to be either full scale or half-scale in any combination. e.g. X1Y1 is full scale, X2Y2 is full scale, or X1Y1 is full scale and X2Y2 if half scale, or visa-versa. Lets assume all signals are sine waves.

    Here are the most significant X1Y1+X2Y2 summed harmonic relationships that occur within a 1:10 range (these also occur in nature, such as in flowers).

    1:2, creates a 2 petal flower or two pointed star
    1:3, creates a 3 petal flower or pointed star
    1:4, creates a 4 petal flower or pointed star
    2:3, creates a 5 petal flower or pointed star
    3:5, creates an 8 petal flower or pointed star
    7:10, creates a 17 petal flower or pointed star.

    Here are some examples from my PLL mixing/modulation console.

    Click image for larger version. 

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    What is so awesome now days is that are numerous ways to this and far more complex harmonic signal generation via computer and software.
    Last edited by lasermaster1977; 06-04-2020 at 19:48.
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  2. #12
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    That’s really amazing. I’m hoping the radiator once it gets here can reproduce some of this.

    i have the old black book with the circuits but those burr browns are impossible to get anymore...and pointless. I love the xlr chips and 4049. Used 4017/18. For sequencing too!

    i miss the days when a hene a speaker and a mirror was satisfying

  3. #13
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    some of those things yes, some of those things... (scratches head).

    Quote Originally Posted by kecked View Post
    That’s really amazing. I’m hoping the radiator once it gets here can reproduce some of this.

    i have the old black book with the circuits but those burr browns are impossible to get anymore...and pointless. I love the xlr chips and 4049. Used 4017/18. For sequencing too!

    i miss the days when a hene a speaker and a mirror was satisfying
    suppose you're thinkin' about a plate o' shrimp. Suddenly someone'll say, like, plate, or shrimp, or plate o' shrimp out of the blue, no explanation. No point in lookin' for one, either. It's all part of a cosmic unconciousness.

  4. #14
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    Quote Originally Posted by kecked View Post
    i miss the days when a hene a speaker and a mirror was satisfying
    I know exactly what you mean. You'll never catch the dragon, my friend. :P
    Those who fail to grasp art are the ones who criticize it.

  5. #15
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    ... some of this fun can be "regained", when diving into laser material processing -- here are enough "alternatives" to the common used galvo-setups or elctronics

    Viktor
    Last edited by VDX; 06-05-2020 at 12:51.
    Aufruf zum Projekt "Müll-freie Meere" - https://reprap.org/forum/list.php?426
    Call for the project "garbage-free seas" - https://reprap.org/forum/list.php?425

  6. #16
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    One other trick is to invert one of the quadrature signals so the circle it's drawing is in the opposite direction... If the quadrature signals are close to the same frequency with one signal inverted the result is a rotating loop, non-inverted is a pulsating circle

    Quote Originally Posted by lasermaster1977 View Post
    Thanks kecked. I saw laserium the first time in Denver in 1976 and a second time in OKC in 1977 at 28 years old. Seeing visuals set to music became my favorite thing, and having a background in music, art and audio made it a perfect fit for me.

    Using the 4 XR2206 waveform generators in a phase-locked-loop configuration really opened my eyes for how two XY sine waves with integer harmonic relationships, with specific phase angle differences, combine to form visual harmonies.

    When discussing harmonics, there must be a reference frequency that we use as the 1st harmonic. Further, lets limit the harmonic range from the 1st to the 10th harmonic. Lets set the 1st harmonic to be 50 Hz, send one phase version of this harmonic to the X axis scanner and another 1st harmonic to the the Y axis 1st harmonic that is exactly 90 degrees out of phase with the X axis 1st harmonic. The scanned image will be a perfect circle. (With a phase-locked-loop oscillator, its phase angle can be set by a 10-turn potentiometer to any desired angle between 0 and 360 degrees and it will lock on that phase angle. If the X and Y signal amplitudes are identical, the scanners will "draw" a perfect circle, 50 times per second.

    Now lets add another independent PLL XY signal pair that can be "added" to the 1st XY signal pair such that the 2 X signals are added together and the 2 Y signals are added together to form a single composite XY signal. This is where it gets very rewarding and the harmonic math is quite simple. And lets limit our 2 XY signal amplitudes to be either full scale or half-scale in any combination. e.g. X1Y1 is full scale, X2Y2 is full scale, or X1Y1 is full scale and X2Y2 if half scale, or visa-versa. Lets assume all signals are sine waves.

    Here are the most significant X1Y1+X2Y2 summed harmonic relationships that occur within a 1:10 range (these also occur in nature, such as in flowers).

    1:2, creates a 2 petal flower or two pointed star
    1:3, creates a 3 petal flower or pointed star
    1:4, creates a 4 petal flower or pointed star
    2:3, creates a 5 petal flower or pointed star
    3:5, creates an 8 petal flower or pointed star
    7:10, creates a 17 petal flower or pointed star.

    Here are some examples from my PLL mixing/modulation console.

    Click image for larger version. 

Name:	Laser 3-5 Yel-2.jpg 
Views:	1 
Size:	1.14 MB 
ID:	56637 Click image for larger version. 

Name:	Laser 3-5 ColorMod.jpg 
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Size:	1.11 MB 
ID:	56638

    Click image for larger version. 

Name:	Laser 7-10 Multi.jpg 
Views:	1 
Size:	3.76 MB 
ID:	56639 Click image for larger version. 

Name:	Lissajous-4.jpg 
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Size:	1.25 MB 
ID:	56640

    Click image for larger version. 

Name:	Taffy's-002a.jpg 
Views:	4 
Size:	1.34 MB 
ID:	56641 Click image for larger version. 

Name:	Richland College-1c.jpg 
Views:	3 
Size:	4.49 MB 
ID:	56642

    What is so awesome now days is that are numerous ways to this and far more complex harmonic signal generation via computer and software.
    "There are painters who transform the sun into a yellow spot, but there are others who, with the help of their art and their intelligence, transform a yellow spot into the sun." Pablo Picasso

  7. #17
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    Quote Originally Posted by laserist View Post
    One other trick is to invert one of the quadrature signals so the circle it's drawing is in the opposite direction... If the quadrature signals are close to the same frequency with one signal inverted the result is a rotating loop, non-inverted is a pulsating circle
    Absolutely! That trick is what thrilled my eyes when I first saw a Laserium show.

    After years of dealing with and learning from the wild and sometimes awesomely surprising world of analog signal processing for laser scanning, it became obvious that emulating this process digitally was far easier via hardware and software. That is how I began down the path to this via the Apple IIe with four (ALDC) 6502 co-processor boards, each with 30K of static RAM and 2K of EPROM, four 8-bit DACs (two for XY, two for XY amplitude). Applied Engineering's 1.5MB memory expansion board and their TimeMaster II real-time clock board. ALDC stood for Apple Laser Display Card.

    Here is an excerpt from the Lasermaster user manual:
    The intent of the Apple based Lasermaster system is to give the user predictable and repeatable creative control over actual presentation of laser graphic show displays. How much computer control is needed or desired is left to the user/programmer’s own discretion and creativity.
    The entire presentation can be fully automated for a hands-off show with all program commands scripted to a time base reference. Scripted “Time” is expressed in minutes, seconds and ticks (00:00.0), were the smallest expression of time (the Tick) is 1/16 of a second. Ticks are expressed by 0-9 and A,B,C,D,E,F characters.

    The user can also elect to manually interact with the scripted program execution through controls on the Lasermaster Console. The tedious task of loading images and performing switch-throwing through the host Apple’s programmed control, leaving hands free for manual, “live” creative show presentation enhancements.

    Each ALDC card is a 32KB computer with (13) 2KB image buffers, 16 shape routines, and 16 scale routines. The Apple host can dynamically load new images while each display card is displaying current image buffers. Shape and scale routines are user defined in SETUP MODE and dynamically loaded to the ALDC cards by the host computer on-the-fly. Images can also be initially loaded and displayed to one or more ALDC cards in SETUP MODE.

    Here is a general block diagram of my Lasermaster system:

    Click image for larger version. 

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    The ALDC card was a four layer PCB and as you will see, very compact. First, here is the wire-wrap prototype board used in development.

    Click image for larger version. 

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    Here is the unpopulated PCB

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    Here is the populated PCB

    Click image for larger version. 

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    A preview dual-trace 100Mhz oscilloscope was used to assist in image previewing. The XYZ (Z=blanking) output of each ALDC card was time multiplexed to a single XYZ output sent to the oscilloscope. XY=scope inputs 1 & 2, Z=scope blanking input.

    I built a total of three of these systems, two for customers and one for me. The four-layer cards for the most part held up fine. A few had problems with inner layer - through hole connections due to less than sterling by the company than made the PCBs for me. Small jumper wires had to be soldered on the backside of most of the PCBs to effect trace connections where through-hole plating did not maintain connections between traces on one or more layers. But at least that resolved inter-trace connection problems.

    I've always wanted to augment my Lasermaster console version with the 4 channel PLL with the two AM modulators. One of these three Lasermaster consoles did include ALL the PLL circuitry of my first console. I've always wanted to add that circuitry to my Lasermaster console for me. It is still on my to-do list. But first I making a new version of the mini-AppleDAC console for icecruncher and me. ;-)

    Here are the three LM consoles

    Click image for larger version. 

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    See what can happen when you're having fun?
    Last edited by lasermaster1977; 06-05-2020 at 12:38.
    ________________________________
    Everything depends on everything else

  8. #18
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    Here are some pics of what turned out to be the prototype of my RYGB, GS G-120PD, A/O, Mixedgas ion laser projector. These shots were taken during a show prep/rehearsal that integrated 9 Kodak AF-1 slide projectors. I used one of my Altec Lansing Voice of the Theater A-5 speaker cabinets as a support for the extension ladder the slide projector stacks sat on. Its multi-cellular horn can just be seen to the left of the left-most slide projector stack. The CR-MG laser projector sits in front of and between the middle and right slide projector stacks. The laser's power supply can be seen directly below the laser head near the floor on the light brown shelf. To its left are the four, blue IntraAction A/O drivers. Additional shots of the projector head follows this.

    Click image for larger version. 

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    The next pic, right to left, shows the 4 A/O cells, to their left is the four XY scanner mounts followed by two lumia tubes.

    Click image for larger version. 

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    The next pic shows the business end of the projector head. These Lumia tubes were great. Ledex rotary solenoids were used for beam flags. God, were they loud. Didn't use them unless noise wasn't an issue. The two Lumia tubes are glued onto plastic 35mm film container caps. An ice pick hole in the center of the caps lets it slide onto the geared 12vdc motor shaft. These two lumia tubes were made by a photonbeam back around 1980-81.

    Click image for larger version. 

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    This next pic is a straight-on view of all-in-one four XY scanner mount. I was looking at this photo the other night and noticed that the two XY scanner pairs on the bottom of the mount are G-115s while the two on top are G-120PD XY pairs. I do not recall why this was. Those are diffraction gratings for the XY scanners, flipped down or up by Ledex rotary solenoids.

    Click image for larger version. 

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    In my next and "final-before-last" threads (FBL), I'll show one of the derivative projector of this prototype with beam paths illuminated, followed by the progression of my GS scanner mounts, over the years.
    Last edited by lasermaster1977; 06-07-2020 at 18:52.
    ________________________________
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  9. #19
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    The customer's projector utilized a Laser Ionics Model 554 3W krypton/argon laser. Here are basic top and front view drawings.

    Click image for larger version. 

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    Standing in front of the projector with the top and front optical table and scanner covers off:
    The projector base is a 6" x 14" x 75" 6061 aluminum channel, black anodized. The 4 large connectors on the left are beam flag connectors, the 4 BNCs to the right are the AO inputs, the two below that are cover and safety interlock connectors. Two Amici prisms were used to spread the wavelengths, one for scanning and one for future additions for cloud effects. The cloud effect direct view prism is out of sight behind the middle partition. The scanner direct view prism is poking through the middle partition, hits a MM1 mirror mount and turns parallel to the middle partition heading to the left. The beam path makes a U-turn, transforms into a rectangular, four corner beam alignment and heads into the 4 IntraAction Model 40 AOMs. The RYGB beams form corners of a precise rectangle that continues to the quad scanner mount. After the beams pass through the AO's they hit their respective beam shutters that are between the AO's and the scanner head which is out of sight to the left of the first two images. The yellow and red beams continue forward and pass through two .25" diameter holes in the vertical scanner mount and land directly on the Yx and Rx scanner mirrors. The blue and green beams follow a similar path but enter .25" holes in both the left and right vertical scanner mounts, exit out the right side of the quad mount and makes a U-turn into similar holes like R & Y and land directly on the Bx and Gx scanner mirrors. The projector version after this one used two right angle prisms for blue and green, glued to the right vertical scan mount plate effecting the U-turn onto the Bx and Gx scanner mirrors. I liked this method the best as it required no adjustment of MM1s.

    Click image for larger version. 

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    Here is my densely packed, 4 banger GS-G120PD scanner mount. For this wannabe, it represents one of my pride and joys.

    Click image for larger version. 

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    Sorry the image has too much contrast which doesn't allow the .25" diameter pass-through apeture holes to be visible. Also, the laser was not on when the scanner mount pic was taken.

    This scanner mount represents the finale of my mounts, so I will only include those that were first and single mount variations to the one showed here, in my next, and FBL post.
    Last edited by lasermaster1977; 12-01-2020 at 18:43.
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  10. #20
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    These posts are amazing. I LOVE looking at this kind of hardware! What an amazing thread.


    Quote Originally Posted by lasermaster1977 View Post
    Click image for larger version. 

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    This quad has me drooling. I love that setup!
    Those who fail to grasp art are the ones who criticize it.

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