power supply LX200 8"

[turonrambar]

Dear group,

I bought a power supple that is rated at; 13.8 VDC, 3 amps.  Is the 3 amps too high?  I can exchange the 3 amps for an 1.5 amp rated power supply.

Thanks in advance.

[lindendave]

Kip,

I have been running my scope on a Radio Shack power supply with the same specs for almost ten years without a problem.  I would note that I use the lighter socket on the supply and use a cable that houses a 3 Amp fuse in the plug for an added measure of safety. The power supply is also solely dedicated to the scope having another for things like dew heaters.

[turonrambar]

Dave,

Thank you for your reply. 
The power supple that I purchased has a lighter socket in the P/S box
and comes with a cord male lighter plug. I asked about an in line furze and they said it wasn't necessary
with overload protection is a 2A/250V fuse. Also, bought a "S" type tip?
What is the rating of your second power supply?  running dew heaters and other accessories?
I use a dew shield here on the south coast of Oregon. What type of conditions do you experience
when using electric dew heaters?   

[lindendave]

Kip,

I am currently out of state so I can not check to make sure what my second power supply is but I know it is rated 15 Amp and was purchased from Buy Reliant and is a Pyramid brand unit. Even though I have a Meade dew shield on my scope I still run dew heaters. I also have a Celestron C102 piggybacked on the main scope and run a total of 7 dew heaters;
2 on the main scope
2 on the C102
2 on the finder
1 on the Telrad

I do not recall where I bought my power supply cord for the scope but I know I changed the internal fuse to 3 Amp. I know it is probably not necessary but it makes me feel better. I had another 15 Amp Radio Shack supply prior to the Pyramid one and it malfunctioned and started putting out close to 20 volts. Because I had wired all the dew heaters directly to that supply there was nothing in line for protection and in the dark I melted the eye piece of my original Meade finder scope so now I protect everything. Here in southern Illinois we have lots of humidity year round and it especially is troublesome in the winter with a roll off roof observatory. If you are interested in a dew heater I would strongly recommend the Dew Buster as it is a quality product economically priced, less than $200, with great support.

http://www.dewbuster.com/default.html

[turonrambar]

Dave,

Thanks for your input on this.

I like to go to star parties, and great spots to view the night sky.
Do you have information, or experience with using deep cycle 12V batteries afield?

thanks again.

[lindendave]

Kip,

Personally I have only been to one star party, prior to completing my observatory. I also have no personal experience with deep cycle batteries though I have read posts from folks who do use them and find them very reliable. From what I have read the consensus is to use the marine type since they were made for numerous recharging. Years ago I did built a portable power supply but it utilized sealed batteries from a scooter and then I only used it a few times before I sold it along with other portable accessories as I was building a permanent observatory for my scope.

[turonrambar]

Dave,

I've only went to one star party and used c-cell batteries.
Last summer we went to Montana, Idaho and Oregon and used c-cell batteries to power the telescope.
I have read so much information on low power issue from c-cells batteries  I want
to change to 12v deep cycle batteries for when I'm in the field. 

I've found excellent conditions at Craters of the Moon in Idaho.

thanks again

[drclay]

I want to jump in here and back up to the dew heater issue in regard to the power supply....NEVER run the dew heater off of the same power supply as the telescope; you must use a separate power supply for the scope that is not linked to any other device, or you really are in danger of a power surge taking out the electronics of the telescope or handbox.

Doc

[lindendave]

Kip,

Doc is absolutely correct on this and I should have made it more clear from the onset of the discussion. My 3 Amp power supply is ONLY for my scope and the 15 Amp runs everything else. You can find many discussion threads on the net where folks have used only one power supply for everything they take into the field and most of those threads will have an issue with the scope and the power going to it. You have already found out firsthand about running on C batteries but hopefully you will dedicate a single power supple to your scope and avoid other gremlins.

Let me take this a little further and suggest, as I do, to periodically test your power supplies with a DVM to make sure they are putting out the correct amperage and voltage. My early lapse in not doing that cost me a 50mm finder scope but it could have been much worse.