Electronics
I was not able to use any of the original circuitry, so I needed to develop the electronics to generate the motor drives, read the encoders, operate the detectors, and communicate to my observing location. These requirements dictated an on-board processor to handle the software/hardware interfaces, and to perform all the four-axis realtime pointing computations.
Additionally, I wanted to act on 'lessons learned' from my previous telescopes, and one of those lessons was to minimize cabling. To that end, rather than have the computer and electronics sitting next to the scope, I had the telescope carry all the electrical support items. In the final version, I had only one cable to one moving part (the pitch/roll head).
Here is my previous scope, a 26" reflector in the hills of West Virginia (Ed Abel's backyard specifically). The cabling is not shown because it was a nightmare.
The electronics had three primary elements; the computer, the motor drives, and the encoders. Here is a photo of the layout I developed, which has the electronic components mounted on a triangular aluminum plate. This plate was then mounted to the telescope's moving azimuth table. I call this triangular plate the 'az table' in later pages. Visible is the computer, the two motor drive circuits, the az encoder, and the two encoder interface boxes. The scope had a temporary eyepiece installed.
The circuit board on the right (above), controlled the altitude and azimuth motors and the right-hand interface box handled the alt and az encoders. The left circuit card controlled the pitch and roll motors, and also drove the filter wheel (sometimes called the 'vane').
Here are the circuit boards being wire-wrapped and tested.
