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Powering the piers

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#1 David81

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Posted 12 December 2012 - 06:07 PM

"Opening Day" for the new observatory (still nameless) is fast approaching. The exterior trim work is 95% done, the electric and networking cables have been buried (mostly) and the interior wiring is coming along nicely.

Now it's time to supply power and data access to the piers. The original plan was to have a central 12v power supply and run AC + DC to each pier. After a bit of rethinking, I'm leaning towards a single run of AC from the breaker box in the warm room to the piers and then a nice small DC power supply + distribution panel at each pier.

Data (USB, Cat6, Firewire?) will run from the opposite side of the warm room and stay as far away from the power as possible.

Like this.

Posted Image

This seems to be a bit simpler of an approach and would keep the power somewhat isolated on each mount.

Does anyone have experience with a power supply similar to these?

NEW 12V DC 12.5A 150W Regulated Switching Power Supply

They seem to fit the bill perfectly. Small size that could be mounted to the piers and not get in the way and adjustable voltage output, just in case.

My one worry is the "quality" of the power coming out of them. The seller claims that they produce clean power, but given their skills with the English language, I'm taking that with a grain of salt. For the price they are asking, it's almost worth just trying it out, yes?

#2 Christopher Erickson

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Posted 12 December 2012 - 07:06 PM

Some switching power supplies can cause noise for some cameras. Easiest way to find out is to set everything up and do some tests. The noise might manifest as vertical or horizontal banding in the images. It might also manifest as a "barber pole" repeating diagonal pattern.

Switching power supplies are more power-efficient than classic heavy-transformer-based power supplies, which means that switchers give off less heat.

#3 Mary B

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Posted 12 December 2012 - 07:41 PM

I went with a power supply from Samlex. Their amateur radio supplies have clean output. Cheapest to feed thousands of dollars in gear? I spent a little more for known quality.

#4 Wmacky

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Posted 12 December 2012 - 08:30 PM

Are you sure you even need A/C at the piers? I decided I don't really require it. Occasional hair dryer use for defogging is all I can think of, and I'm willing to stretch a cord from the wall in that case.

#5 Tom and Beth

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Posted 12 December 2012 - 09:56 PM

+1 for Wmacky.

I use an Acopian power supply, bought off fleabay to power both piers and other low power needs.

#6 David81

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Posted 13 December 2012 - 02:37 PM

Thanks for the tips guys. I'll definitely look into Samlex and Acopian.

My main concern was something that would be small enough to mount directly on the piers and not create a large heat plume, hence the choice of switching varieties. I don't mind paying a bit more if it will be higher quality, I just happened to run across those on ebay and thought it might be worth a shot.

As far as running AC to the piers, I figure I'm better safe than sorry on that. This way I can just run one AC line and then convert to 12v at the pier to get both AC and DC availability.

This all may change as I do more research, of course :)

#7 David81

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Posted 13 December 2012 - 05:46 PM

When evaluating different power supplies are there any guidelines I should be following, spec-wise?

I'm thinking at least 5A per pier, probably more like 10A to be safe. When it comes to the other specs though, I'm a bit lost. What should I be looking for in terms of ripple noise, efficiency, voltage regulation, etc.?

#8 Tom and Beth

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Posted 13 December 2012 - 06:56 PM

When evaluating different power supplies are there any guidelines I should be following, spec-wise?

I'm thinking at least 5A per pier, probably more like 10A to be safe. When it comes to the other specs though, I'm a bit lost. What should I be looking for in terms of ripple noise, efficiency, voltage regulation, etc.?


As a minimum, I'd look at REGULATED power supply as well as overload protection. If you have any HAM operators you can talk too, take their advice (that's why I have an Acopian ;-) )

BTW, on your other post. I have two AP1200s. Slewing they MIGHT hit 2 Amp each, but rarely that high. Normal tracking is around 1/2 amp. These are actuall measurements using a good Amp meter. 12 Guage wire is overkill, but I ran it anyway from the PSU to each pier. At the pier, I split off and step down the voltage so I can run fans on one scope, or if I ever get into using a camera. One of the reasons I went this way is that when Lightning is around, all I have to do is unplug the power supply, reducing the possibility of damage.

#9 mich_al

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Posted 13 December 2012 - 08:35 PM

Something to consider is that not all mounts use 12V DC (Losmandy for one). Who knows what you'll have out there down the road. Planning for flexability is always a good idea.

#10 Mary B

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Posted 13 December 2012 - 08:43 PM

I am a ham operator :lol: that is why I recommended Samlex. Good prices here http://www.gigaparts...=DSW-138&typ...

#11 Wmacky

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Posted 13 December 2012 - 08:57 PM

Hello Mary, I was a new General ham operator for 4 whole months earlier this year, but no longer! The good news is the I now have this PS for the new observatory!

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#12 Tom and Beth

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Posted 13 December 2012 - 10:14 PM

There you go, Two HAMS :lol: :roflmao: :lol:

#13 Calypte

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Posted 14 December 2012 - 02:59 AM

Something to consider is that not all mounts use 12V DC (Losmandy for one).

Mine does.

#14 Mary B

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Posted 14 December 2012 - 06:30 PM

www.powerwerx.com sell anderson powerpole stuff for making connections. The rigrunners are fused outlet blocks powerpoles plug into. I use them for all 12 volt distribution including the observatory.

#15 mich_al

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Posted 15 December 2012 - 09:52 PM

Something to consider is that not all mounts use 12V DC (Losmandy for one).

Mine does.


I thought they prefered 18V. Anyway, you get my meaning.

Al

#16 Calypte

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Posted 16 December 2012 - 12:34 AM

Something to consider is that not all mounts use 12V DC (Losmandy for one).

Mine does.


I thought they prefered 18V. Anyway, you get my meaning.

Al

My 2001 G11 is non-Gemini. It uses 12VDC. Maybe the Geminis are different.

#17 David81

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Posted 17 December 2012 - 01:14 PM

Thanks again for all the tips guys. Those RigRunners sure do look nice.

I have a bit of time until I'm ready to do the final wiring at the piers, so I'm keeping an eye on ebay for a nice deal on some small power supplies.

#18 Startraffic

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Posted 17 December 2012 - 02:26 PM

I have a G11-G1 & an HGM-200-G2, both are happier running on a regulated 15VDC. I got a Pyramid 5-24VDC 20A variable power supply. Nary a problem running BOTH at the same time.

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