In this thread I will post things that show what I (or others, feel free to join in on this post) came up with when starting out on the amazing enterprise and journey of becoming a laserist, building projectors and control consoles and special effects for pleasuring the eyes and ears of our patrons. For me the journey began when I was working as a theater union projectionist, having previously worked as an audio recording engineer. After a few years absence from my first two years of college I took some classes at a new local junior college taking astronomy, geology, anthropology, calculus, trig, ac/dc electronics and other things. I was taken back, blown away, that the astronomy classes were taught in a 40 ft. planetarium dome with a Spitz 512 star projector and was equipment with a fast array of other visual special effects projectors and 35mm slide projectors, planetary orrery, etc. It wasn't long that I volunteered to help with producing audio taps used in multitudes of astronomy related planetarium shows for the public. During my 2 or 3 year of being a volunteer planetarium nerd and having audio/electronic and optical skills the planetarium director urged me to build a laser projector like Laserium. After a brief education on what all that entailed I jumped in with all feet. I had the opportunity to create laser shows at this facility and make money in the process. The college and I came to a business agreement to split the proceeds by selling laser show tickets to the public. After quite a few months, I put together a simple business plan, showing expenses and cash flow and presented it to my local bank to get a short term loan, which I believe was for $8,000. That was enough money to do a lease/purchase with Coherent Radiation for a 1W mixed-gas krypton/argon ion laser, purchase eight GS G-115 open-loop scanners from General Scanning with front surface mirrors and mirror mounts, (I couldn't afford to buy their scanner drivers or scanner mounts and built my own. More on that later.) The rest of the money went for IC chips, sockets and other electrical components for building the myriad of circuit boards for building a phase-lock loop/free running set of sine, triangle and square wave generators along with amplitude modulation oscillators and other good stuff. My primary shop tools to make many of these things were a Craftsman table saw and drill press. I cut slots in aluminum panels for slide controls on my table saw.
My projector was going to consist of RYGB scan colors from four sets of XY scanners plus RYGB special effect "clouds". I mentioned in another recent Lumia post that back then we called them laser clouds, regardless of the type of cloud that resulted from the "effect" of the distortion material. For creating Lissajous patterns of many forms and variations the console had four PLL oscillators that could be phase locked or in free run mode that generated sine, triangle or square wave patterns from a base frequency of 45 Hz to 450 Hz, select-able in harmonics 1 through 10 of 45Hz. (in free run mode the high end frequency was slightly higher.) There were two independent PLL oscillators one pair for X and the other pair for axis outputs. Each oscillator output magnitude was independently controlled by an audio taper slide potentiometer. PLL outputs 1 and 4 created an XY pair and 2 and 3 created a 2nd XY pair and could be individual set for a phase-locked harmonic from 1 to 10 and then summed together via slide potentiometers, (Ch.1 + Ch.2 for X's output and Ch.3 + Ch.4 for Y's output). The was a phase control knob that could set the phase-locked phase difference between the X and Y channel outputs. The sum of the four PLLs were sent to each of the four XY scan drive amp pairs. In addition, each PLL and/or free run oscillator could be switch selected to be amplitude modulated by one sine, square oscillator, while a second oscillator could be used only for CH.3 and Ch.4's outputs.
This first photo is the finished result of my 1st generation PLL console.
The 2nd photo shows how it eventually evolved. To the right is my old Heathkit dual-trace scope I used for an XY output preset monitor. The toggle swiches above the console were the ON/OFF flags for the 4 scanner beams and 4 cloud beams, plus ON/OFF switches to control relays that turned Synchron motors on or off (that drove the cloud disks.) (edited 12/01/2020 - change could beams to cloud beams)
The console case was recycled by me from a DIY 2 channel, low impedance microphone mixer my dad built years earlier.
In 1979 I added additional XY image source switch to allow the Apple II's AppleDAC outputs to be selected on XY1 or XY2 channels.
These next photos are is the 3rd generation of this same basic console.
This photo shows how wire-wrap methodology helped compact the circuitry. There was no way I could afford to have PC boards made back then but eventually I did.
So, by this time my principal image sources were from the 4 channel PLL outputs and the Apple IIe's AppleDAC. Also, the version 3 console had digital blanking oscillators that were used in conjunction with the Apple's image blanking and IntraActions Acouto-Optic modulators, one for each of the four colors.
Next, I will show images of my very first method for blanking the image beams with a spinning cardboard blade (only one every got partial burned by the 1W beam) placed on a lead screw in the beam path right where it exists the laser....AND.... DIY scanner mounts, from my 1st ones to the last variations of my quad XY, RYGB high density mounts for GS G-120PD scanners, still using the krypton/argon 1W mixed gas ion laser or the krypton only variant. You guessed it, all but my latest, greatest scanner mounts were made with 3/8" aluminum 6061 bar or plate, a table saw and drill press, and thread taps.
The saying, "necessity is the mother of invention" holds true and I hope those laser enthusiasts among you will take inspiration from these and the posts on this forum.