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Progress in Apache Junction

Started by NebSteve, 10/20/2010 06:59AM
Posted 10/20/2010 06:59AM | Edited 10/20/2010 07:01AM Opening Post
Yes another story... wink
The new observatory is about 200 feet from the house. If any of you have had to dig a trench in the Phoenix area (short of hiring somebody with a backhoe) you know how hard the caliche can be. For those of you in other parts of the country, imagine sand and clay mixed with softball sized river rock. It's as hard as concrete.

Needless to say I'm reluctant to start a trench for an electric line. So it's a choice between 110 AC or producing my own power on site. The solar kits commonly available are meant to charge a 12 volt battery. Since that's what I'd need for the drive system at the occasional star party, it makes sense.

I just purchased a SkyProbe Goto system that runs on 110 AC. It's an older system for converting a Losmandy drive to Goto but it does work. The laptop can run on 12 volts DC input and has an internal battery, so no problem there. The motor driver runs on 110 AC but on the inside converts that to 12 volts DC for the electronics. It also has a 12 volt output. It should work as an input for 12 volts off a battery, so substituting solar for grid power is possible. If necessary an inverter could be used, but that adds another component and a bit more drain on the batteries.

All that's left is picking out a solar system. OK, bad pun. I figue 60 watts ought to do it. That's 12 volts at 5 amps all day. More than enough to charge batteries for the system and for the little bit of light I intend to install. In this part of Arizona there will be lots of daylight.

The wiring was installed last night. The pier was filled with sand, rocks, shredded rubber and vermiculite. I still need to compact it and re-grout the base of the pier. Tell you more about vibration dampenning after that.

I was hoping for first light for the observatory sooner, but might wait till after the All Arizona Star Party.

That's it for now,
Posted 10/21/2010 02:57PM #1
Steve I've rented a Ditch Witch from the local rental store and cut through 200' of caliche in just an hour or two. The cost for the rental was $75. Digging in this soil by hand is suicide but I'd rather have A/C power in my home observatory than battery power any day. Martin

"In the beginner's mind there are many possibilities, but in the expert's there are few." Shunryu Suzuki[COLOR="Blue"][/COLOR]