Jump to content


Photo

How many amps does a CGEM draw?

  • Please log in to reply
8 replies to this topic

#1 mistyridge

mistyridge

    Gemini

  • *****
  • Posts: 3036
  • Joined: 28 Oct 2005
  • Loc: Loomis, CA

Posted 15 August 2010 - 12:51 AM

I am looking for a 12 Volt DC power supply for my CGEM and was wondering how many Amps it draws at Max power draw. I will not be using batteries as I have a ready AC supply.

#2 KyleROwens

KyleROwens

    Vostok 1

  • -----
  • Posts: 103
  • Joined: 25 Jun 2010
  • Loc: Dallas, TX

Posted 15 August 2010 - 07:10 AM

Well the transformer is rated for 2.5 amps at 12 volts so I'd imagine that's a pretty good place to start.

#3 Tiflo

Tiflo

    Lift Off

  • -----
  • Posts: 1
  • Joined: 11 Aug 2010
  • Loc: Rouen, France

Posted 15 August 2010 - 07:13 AM

Hello

According to the website of Celestron, the CGEM draw 1.5A at 12VDC.

http://www.celestron...odID=548#idTab3

Tiflo

#4 Chris Rowland

Chris Rowland

    Viking 1

  • -----
  • Posts: 586
  • Joined: 28 Feb 2005

Posted 15 August 2010 - 07:38 AM

The short answer is that I'd get at least a 4A Regulated PSU.

There can be a surge when the motors start that's much higher than the steady state current, My NS11 take up to 2.5A for a millisec or so as the motors start. I measured it with an oscilloscope so I could see the surge, a normal meter won't show it.

If the PSU can't supply this the voltage drops and this can corrupt the microcontrollers in the mount. This can cause all sorts of strange behaviour, from bad pointing to runaway slews.

2.5A may be enough but a PSU that can give more won't be much more expensive.

Chris

#5 mclewis1

mclewis1

    Thread Killer

  • ****-
  • Posts: 11071
  • Joined: 25 Feb 2006
  • Loc: New Brunswick, Canada

Posted 15 August 2010 - 08:28 AM

Around .5amp when just tracking. When the motors are slewing at high speed you can see numbers up over 2.5amps as Chris has mentioned. Overkill here is your friend (within reason) ... bigger and well protected and regulated is always better with a power supply and bigger is better with a battery.

My favourite power supply for mounts like the CGEM is the Pyramid -9KX.

#6 chollman

chollman

    Mariner 2

  • *****
  • Posts: 213
  • Joined: 24 Apr 2008

Posted 15 August 2010 - 09:55 AM

I use a lcd computer monitor power supply 12v. 5.0 amp max. for powering my cgem. Works fine and you can find them inexpensive on ebay.

#7 mistyridge

mistyridge

    Gemini

  • *****
  • Posts: 3036
  • Joined: 28 Oct 2005
  • Loc: Loomis, CA

Posted 16 August 2010 - 12:21 AM

Thanks for the info. There is a big electronics supply store in my area, they will have what I need. I will get a power supply large enough to power the CGEM and a Mallincam which I have on order. I don't care for batteries as they have a bad habit of going dead in the middle of a long viewing session.

#8 JackR

JackR

    Vostok 1

  • *****
  • Posts: 118
  • Joined: 20 Feb 2008
  • Loc: Surprise, Arizona

Posted 16 August 2010 - 05:07 AM

Radio Shack carries a very nice AC to DC Power Supply. This is what I use to run my CGE mount.

http://www.radioshac...oductId=2103959

Haven't had a problem.

Jack

#9 mistyridge

mistyridge

    Gemini

  • *****
  • Posts: 3036
  • Joined: 28 Oct 2005
  • Loc: Loomis, CA

Posted 17 August 2010 - 01:12 AM

Thanks I Just ordered a 5 Amp. The 3 amps were out of stock.






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics