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Mystery power supply OK?

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#1 SeattleScott

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Posted 09 November 2018 - 01:09 AM

Recently picked up a used LXD75. Need a cigarette lighter style power adapter for it. Rummaged through the miscellaneous cable bin and found one that fits perfectly. Not sure what it went to originally but I can run Autostar and drive the motors. Is there any reason to be concerned that it isn’t the official Meade power adapter? Or did I just save myself $20?

Scott

#2 otocycle

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Posted 09 November 2018 - 03:41 AM

No concern if the tip fits the LXD-75 power jack and is center positive.  Would also like a fuse in the 12VDC car adapter end if possible to protect the mount.



#3 SeattleScott

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Posted 09 November 2018 - 08:52 AM

Sounds good thanks!

#4 SeattleScott

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Posted 09 November 2018 - 09:18 AM

Sounds good thanks!

#5 Midnight Dan

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Posted 09 November 2018 - 09:03 AM

>> Not sure what it went to originally but I can run Autostar and drive the motors.

 

It sounds like you've already plugged it in and tried it.  Without looking at the specs, that can be dangerous, but since nothing blew up, you're probably good to go.  But "fitting perfectly" is definitely NOT indication that it's safe to use.

 

On all of these power supplies, you'll see information that will tell you if it's ok to use.  One is a symbol that looks like a C with a dot in the middle.  The C and the dot each have a short line going out to the side labelled + or minus.  This is a "drawing" of the tip of the connector with the dot being the center conductor and the C being the outer shell.  This lets you know wether the center conductor (the "tip") is positive or negative.  Reversed polarity can definitely kill electronics, so you want to get that right.

 

You also need to look at the voltage output rating and make sure it's 12V DC.  Some of these power bricks put out AC, which is not what you want and could cause damage.  If the voltage is too low, it won't power your gear; too high and it can damage your gear.  Most astro gear can take a range of voltage from about 11 to 14 because they're designed to run off of automotive power, which can vary somewhat depending on battery condition.

 

The last thing to look at is the output current, which is rated in amps (A) or milliamps (mA).  You need to look at the manual for the device you're powering and see how much current it needs.  If the supply is rated less than that, it may not power your device.  If the current rating is higher than your device needs, that's not a problem.  The device will only draw as much current as it needs.

 

-Dan


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#6 SeattleScott

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Posted 09 November 2018 - 09:04 AM

Sounds good thanks!

#7 WadeH237

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Posted 09 November 2018 - 06:53 PM

You can get a simple multimeter cheap.

 

I check voltage and polarity of everything before I plug it in (actually, I check voltage, check polarity, hack the ends off, and convert to PowerPoles).  I would hate to fry an expensive mount by saving a few bucks on a power supply and not testing it first.


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