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Mount Power Question

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#1 kpendlebury


    Vendor Main Sequence Software

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Posted 12 May 2010 - 11:06 PM

I currently own a CGEM mount and in the next 6 months or so might upgrade to a Losmandy G11 with Gemini.

The CGEM is pretty happy with my 12V, 3A power supply, but I have read many reports that this is an "iffy" range for the G11 and that it is happier at ~18V.

My question is this (please keep in mind I don't know much about EE stuff... even basic stuff):

I currently own a 0-18V, 0-3 Amp AC to DC power supply that I would like to use for mount power if possible. The part that confuses me is that it clearly states that it has constant voltage -OR- constant current and has a dial to control each. Is this type of power supply adequate for powering a DC mount or am I getting myself into trouble heading down that path? Losmandy states that the G11 requires 1.5A.

If interested, I have this model:

Thanks for any advice.

#2 John Noble

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Posted 12 May 2010 - 11:55 PM

(putting on my electro-boy beanie)

It will work fine in the sense that it will supply enough current (that's the "amps") at the correct voltage: just set the voltage to 18VDC (or whatever the mount wants) and don't use the constant current mode (or crank the current limit up to maximum). I seriously doubt the mount draws 1.5A all the time--that's probably the maximum when ramping up to a full speed slew.

BUT ... lab equipment like that isn't made to be out in the damp night air--if there's significant dew you will have problems sooner or later. I'd look into using 12 or so NiMH rechargeable batteries for 14.4VDC nominal. You might get away with AA size ($2.50/ea. for Sanyo Eneloop at Amazon plus $30 for a La Crosse Technology BC-700 charger), which would be mighty convenient. If not, D cells with 4-5X more capacity would definitely do the job ($10/ea.).

Better yet, ask Losmandy what they suggest for power. :)

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