> Date: Sun, 20 May 2001 21:06:15 EDT
> Subject: Re: [M]: Remote power - what do yo use?
>
> On a related issue, how long do you think a Meade 8" LX200 would run if
you
> hooked it to a 12V deep charge marine battery and just left it on?

The LX200 draws an average of about 1.5 amps, so the number of hours would
be the amp-hour rating of the battery divided by 1.5, provided the LX200 is
the only thing you're running.

> Date: Sun, 20 May 2001 18:48:04 -0700
> Subject: RE: [M]: Remote power - what do yo use?
>
> As a newbie who just got an LX200 this may be a dumb question but why
can't
> you simply plug the 12 to 18v Meade converter into your car/truck via the
> power outlets and run your scope etc off the vehicle battery. As I read
the
> posts on this list it looks like I will be spending a ton of money on EP's
> and other goodies and can skip the portable batteries/power packs for
awhile
> or am I overlooking something.

You certainly can. Whether your car has enough reserve power to run it all
night, and then start in the morning, is what we aren't sure of. For a
couple of hours it certainly is no problem.

> I use the 12v to 18 volt unit that Meade sells. It's over priced for
what
> it does but it does what it's supposed to do, and reliably, and safely for
> the electronics in your scope. ...
> ... Others on this group have made mention that they use power
> inverters or just plain 12 volt power supplies. You may want to be
prepared
> for repair costs if you cut corners too much. To me, it's just not worth
> it.
>
> Rick Wisniewski, Vancouver, WA

Well... Volts are volts. There's nothing special about the LX200's power
requirements. What is vital is to always connect the positive side of the
supply to the center conductor of the coaxial connector. Meade also says
you must always have a 1.5-amp slow-blow fuse in the power line feeding the
telescope; I'm guessing the primary reason for this is to protect against
damage if pos. and neg. are reversed. As soon as my LX200 is out of
warranty, I'm going to modify it by adding a diode to protect against
reverse power connections and to mount the 1.5-amp fuse internally.

But the LX200 is not going to be damaged by running on less than 18 volts.
The incoming 18 (or 12) volt supply goes only to the motors, whose speed and
power depend on the voltage. The computer itself runs off 7805 regulators
which will produce correct output quite happily with as little as 7 volts
coming in.

(Can someone tell us what happens if an LX200 is connected to the power
backward? Does it fry just the 7805s or also something else?)

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