Around late August 2008 I purchased an old Celestron 8 (orange tube) telescope including a Celestron Quartz Crystal Drive with Handbox (henceforth referred to as QCDH). The QCDH is a cute (if primitive) little unit which can run from 110VAC or from a 12VDC battery. Since the scopes drive motor runs on 110VAC and its speed is a function of the 110VAC frequency, the QCDH is essentially a variable frequency DC-to-AC inverter. However, I don't like "black box" electronics, so for two days I searched high and low through the internet for schematics for the QCDH with zero success. Finally I had a stroke of genius: email Celestron! Surely they would have schematics for their old equipment. Alas, no. I probably would have ignored the matter since the drive electronics seemed to work fine for the first few weeks. But of course the day came when I took the scope and QCDH to the desert and was greatly disappointed when the scope would not track. Therefore I was sort of forced to ferret out the schematics for the QCDH by hand so I could troubleshoot the darn thing. Given the trouble it took to get the schematics, I figured I'd post them on the internet so if anyone else runs into the same situation I did, perhaps they can benefit from the work I did. The schematics are Figure 1 and Figure 2. I have included several photos of the outside and inside of the unit to assist in proper identification.

Figure 1 - Celestron Quartz Crystal Drive - Main Unit Figure 2 - Celestron Quartz Crystal Drive - Handbox

I'm getting tired. I'll finish this up later. Yet to do: add annotated photos add disassembly notes add TIP30C equivalency with TIP42/A/B/C transistors

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updated 31 October 2008 0250 pdt