The KPVT upgrade is gradually moving along. We have tried to focus on items of the KPVT upgrade that would transfer to SOLIS should it become a reality. Items such as the new hand paddle, the guider detector, motor drivers, driver electronics, and communications and control software are all aspects that are fundamental upgrades to the KPVT, but are also directly applicable to SOLIS.
Ed Stover, Carol Leiker and Dave Jaksha have made excellent progress in defining, constructing, and operating a prototype multi-function hand paddle. A set of liquid crystal graphics displays with integrated switches are packaged into what is basically a display/button array. The interface to the hand paddle is RS232 from a control computer, which loads the image data to display, and reads and interprets the switch closures from the hand paddle. The system control then is through the control computer. Ed has built a prototype unit and is currently working on its packaging. Dave has defined a (more or less) complete set of menus to define hand paddle functions for telescope, grating, and tank control. Carol has implemented the control computer code to load the image bitmaps, configure the displays for various hand paddle functions, and read the switch activity.
Work continues on the new guider detector. The new guider will consist of eight linear 256-element CCD arrays with associated A/D converters arranged around the limb of the guider solar image. Each element of the detector is digitized and fed to a Digital Signal Processor board with a limb detection algorithm to determine the limb position on each of the arrays. The eight detected limb positions are then processed to determine the disk position error. The error is then digitally filtered. High-frequency signals are sent to the #4 mirror control and low speed signals are sent to the #1 and #2 mirror control for tracking. The unique element of this design is the observing position weighting of the guider signals.
Lonnie Cole