CYGN-A

[Greg]

Woah, there's a rail indicator with no voltage and polarity.

[laserist]

Yes, that's a test point, and I believe the voltage indicator should be +15, but it's 3am... Adjust the trim pot so the voltage at the test point is zero when the sweep data byte is 10000000 or maybe 01111111 (5v). At 5 Volts in there's no sweep. At zero it sweeps max. At 10 it sweeps max the other direction. (Not the other axis, that's what sweep direction does.)

Summer madness was nice. The lumia effect used an interesting standoff made of a thin perforated metal. It was made up of about 1/8 inch holes in a hex layout, and was maybe 2x2 inches square. They would dip a piece of the metal in a lacquer, and rotate it slowly with the metal part vertical until the lacquer setup. The result was a hex array of 1/8 double concave lenses made of the lacquer. They weren't good lenses - which actually added to the effect. As I recall the standoff was about 3/4 of an inch above a rotating disk, bu I don't remember which one was used originally. As Richard alluded, we tended to mix and match as time went by.

There was this whole proprietary thing going on way back when. It was understandable. A fair amount of effort went into developing the stuff that made Laserium stand out. The day of the premier at my first installation the director of the planetarium walked up with about 100 sheets of paper and asked if I'd look at this laser documentation and tell him if it was any good. So I looked through it and said yes it's good - it's ours. Somebody, who will remain nameless, (In all honesty, because I never bothered to remember his name.) had redrawn a number of Laser Images drawings with their xompany's name in the header block. Stupidly they drew them with exactly the same layout and call outs. So not only were A1, C1, R1, & U1 through N, all in the same relative places, they all had the same call outs. Embarrassing for somebody.

Someone did a review saying Laserium could become a standout art form of the future, or something like that. Ivan loved it, but I don't believe something becomes a stand out art form in secret. Now that Ivan's gone, I'm willing to roll back the secrecy for whoever is interested.

[ronhip]

Greg,

I can't attach the "6B alignment procedure" PDF because of the 5MB attachment limit (it's 14.2MB), but you can get it here:

https://media-archive.exploratorium.edu:5001/sharing/1RFDPfuPx

There's a section on the spiral generator in there. It's a rough document... Hope this helps.

Ron

Woah, there's a rail indicator with no voltage and polarity.

[Greg]

That's absolutely great! Thanks Ron. That has a lot of important info I haven't seen before. It even mentions the KQO, which so far has been shrouded in mystery. The hand drawn waveforms are charming.

Photo shows the current state of the SPGN build. I'm sorry I can't post the wiring diagrams I draw up for these module rebuilds, but let me know if you want them for the archive, and I can email you them.

[Greg]

Photo shows the SPGN wiring complete ready for testing. There is an empty socket to receive the BB4302 if one appears, but for now I'll use an externally generated ramp.

The alignment procedures document posted previously by Ron makes it clear which documentation packages are my most sought at this time: FXCY, AUMD, and IMRT

[Greg]

It appears that the AD633JNZ 4 quadrant multipliers I bought are counterfeit garbage. I should be able to get the real ones in a couple of weeks or so. Sorry for the delay.

[Greg]

Brian and Ron have come through again and provided some more previously unseen documentation, which includes the circuit called the KQO. This circuit is supposed to produce a spiral shaped cycloid. In the following hasty build, the P Channel JFET component had to be substituted for what I had on hand. This substitution may or may not be contributing to the observed problem(s) with the output.

The photo shows the clock signal, which I believe is doing what it is supposed to: a +15V DC duty cycle of around 80msec that briefly drops to ground.

I have a potentiometer between the L and M nodes (KQO "Q" control) but presence or absence of this resistance doesn't affect the output at this time.

The XY mode output shown is the 0 degree and 90 degree outputs, from nodes N and P. One can see there is some evidence of quadrature, and something that looks like a fly back, but something isn't right. Investigation continues.

[Greg]

Wiring error discovered. Two of 3 sections of the circuit appear to be working.

[mixedgas]

That is a beautiful thing...

Steve

[laserist]

Hey greg, You'll need this too:





The symmetry effect is nice & subtle. The Q Pot was a 10K, ten turn linear, and the symmetry was (I think) a dual 10k linear.