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cem120 power connection options-layout and or rigrunner?

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#1 markm75c

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Posted 17 September 2019 - 01:19 PM

I've got a thread going on with my ac to dc power ideas and rigrunner 4008 in mind (also going to be in a nexdome dome + edge 11 hd with dovetail D series on the top, possibly where ill put a 7 port usb 3.0 hub and the rigrunner).  

 

The cem120 of course has its hub with power outputs, off memory i think 2, 5amps and 2 1amp.

 

Ill have more than this in need of powering, so that lead me to think that doing the rigrunner setup was best (and not really using any of the power off the hub of the 120).  Downside of course, defeats the purpose of the power hub and thus at least 1-2 dangling power cables from the rigrunner (mounted either on the mount or on the OTA).

 

As of now i have power needs:

5amp to the mount

3amp to usb 7 port hub (need at least two 3.0 usb so i have to use the hub too)

5 amp? astrozap dew controller (unsure if 5amp)

3 amp to asi294 pro

future to filter wheel possibly

maybe 5 amp? unsure on amps, to dome rotator control 

 

 

 

I know some use power from two dc sources, one to the mount then rest to the other devices.  I'm thinking of just powering both the mount and the other devices straight from the rigrunner.  I will probably mount the powerwerx 30amp ac to dc unit right on the side of the pier as well (hoping the heat from the unit will stop evening generated condensation, or maybe ill put shields above the dc unit and above my mini pc on the pier side).

 

 

So for other cem120 users, how did you end up doing things.  Do you have any photos of your layout?

Anyone strictly using the rigrunner option?

 



#2 rgsalinger

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Posted 17 September 2019 - 02:17 PM

I have my CEM120EC2 running the fans, the focuser and the dew heaters built into my PW 12.5 along with the usual 2 cameras and filter wheel without any power problems. I have 5 amp power supplies going to each of the aux power cables and a third power supply going directly to the mount. I no longer need to use my rig runner at all. I think where you are going wrong is that you think you'll need several amps coming from your own hub. The hub built into the CEM120's supplies full power to anything you attach to it. So, actually you have more than 10 amps, not that you will need it. My system, with computer on it draws 7-10 amps total based on the cheap watt meter I used to measure things. 

 

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#3 markm75c

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Posted 17 September 2019 - 02:33 PM

I have my CEM120EC2 running the fans, the focuser and the dew heaters built into my PW 12.5 along with the usual 2 cameras and filter wheel without any power problems. I have 5 amp power supplies going to each of the aux power cables and a third power supply going directly to the mount. I no longer need to use my rig runner at all. I think where you are going wrong is that you think you'll need several amps coming from your own hub. The hub built into the CEM120's supplies full power to anything you attach to it. So, actually you have more than 10 amps, not that you will need it. My system, with computer on it draws 7-10 amps total based on the cheap watt meter I used to measure things. 

 

Rgrds-Ross

Darn, looks like i may end up returning / cancelling the rigrunner?

 

Well the cem120's dec has two 5amp outputs on the left that are certainly usable.  But, isnt the dec power fully supplied by the 10amp secondary input in the middle?

 

I could use the two on the left for:

3amp camera power

3amp usb hub (unless i just use the built in usb on the dec and swap the usb 3.0 power cable from asi224 and 294)

 

But then i'd not have any left, although i think the aux port can push out 10amp and a y splitter cable can be "made" (unsure on any of this).

 

If this is the case then there is more available.

 

But with all this i still have a few that need power so i dont see how to avoid it unless i split things off the dec (y cables?)

 

You arent using DC (generator) at all now?



#4 rgsalinger

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Posted 17 September 2019 - 03:24 PM

I have no idea that the term "dec power supply" means. All I do is split the two 5 amp connections on the west side of the mount with simple Y pin plugs I picked up on Amazon. You are not going to get significant voltage loss over 2 feet of power cables with low gauge cabling. Look it up, don't listen to those who insist on running heavy duty cables. My focuser gets power from the 1 amp connector on the east side of the plate.

 

There's is no need whatsoever for a USB hub unless you have something quite unusual going on. You have 4 USB 2.0 ports and one USB 3 port. While technically, the USB 2 hub is not powered, again, you're going to be using very short cables and so it's just not a problem. The USB 3 port is powered. When I use my USB 3 camera (ASI 1600) I use the port. The reason one needs a powered hub - and I have one on my MX+ - is that you may need to run long USB cables to your computer. My computer is about 3 feet away from the mount at most. So the total length of any USB cable is about 8 feet at most.



#5 markm75c

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Posted 17 September 2019 - 03:34 PM

I have no idea that the term "dec power supply" means. All I do is split the two 5 amp connections on the west side of the mount with simple Y pin plugs I picked up on Amazon. You are not going to get significant voltage loss over 2 feet of power cables with low gauge cabling. Look it up, don't listen to those who insist on running heavy duty cables. My focuser gets power from the 1 amp connector on the east side of the plate.

 

There's is no need whatsoever for a USB hub unless you have something quite unusual going on. You have 4 USB 2.0 ports and one USB 3 port. While technically, the USB 2 hub is not powered, again, you're going to be using very short cables and so it's just not a problem. The USB 3 port is powered. When I use my USB 3 camera (ASI 1600) I use the port. The reason one needs a powered hub - and I have one on my MX+ - is that you may need to run long USB cables to your computer. My computer is about 3 feet away from the mount at most. So the total length of any USB cable is about 8 feet at most.

 

By dec power supply i meant the saddle power, the two 5amps you speak of on the left.  I assumed that whole section only had total output of 10amp (but someone in a dedicated cem120 forum claims it has 20 somehow, not sure how if the most coming in is either 10 or 15 if you count the main mount 5amp).

 

I guess it could be it doesnt need much beyond this, so maybe all this is unneeded then (no need for dc or rigrunner or maybe i should use the dc for the 10amp input and the 5amp input)

 

The usb hub was convenience to not have to swap the usb 3.0 cable from each camera and just leave them connected.


Edited by markm75c, 17 September 2019 - 03:38 PM.


#6 rgsalinger

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Posted 17 September 2019 - 07:25 PM

The CEM120EC2 is rated for 5 amps for each outlet on the west side of the mount. However, that's not to say that you can't deliver a bit more safely. It's just what iOptron is saying that the warranty covers. I can't work out why you would need more than 120 watts of power, in any case. Remember this is NOT including the mount or the computer. I run my dew heaters all night long on nights when I suspect they may be needed. That way I don't get heavy dew and don't need to turn them up. I'm fully automated so I just go to sleep once I get a run going.  

 

Unless you are doing high frame rate lucky imaging, USB 3 is more or less pointless. For a long time I had my ASI1600 connected to USB 2 and never noticed an issue. Right now I have my ASI071C connected with a USB 2.0 cable to the Versaplate on my MX+ and again, no issues arise that I can detect.

 

If you have some need to support two USB 3 cameras running at high frame rates then you will need a hub, of course but again, not sure what you would be actually doing to require this. When you are guiding the download from the guide camera is maybe 20KB every second at most. USB 2 supports 10000 times that rate. 

 

Rgrds-Ross



#7 markm75c

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Posted 19 September 2019 - 10:37 AM

The CEM120EC2 is rated for 5 amps for each outlet on the west side of the mount. However, that's not to say that you can't deliver a bit more safely. It's just what iOptron is saying that the warranty covers. I can't work out why you would need more than 120 watts of power, in any case. Remember this is NOT including the mount or the computer. I run my dew heaters all night long on nights when I suspect they may be needed. That way I don't get heavy dew and don't need to turn them up. I'm fully automated so I just go to sleep once I get a run going.  

 

Unless you are doing high frame rate lucky imaging, USB 3 is more or less pointless. For a long time I had my ASI1600 connected to USB 2 and never noticed an issue. Right now I have my ASI071C connected with a USB 2.0 cable to the Versaplate on my MX+ and again, no issues arise that I can detect.

 

If you have some need to support two USB 3 cameras running at high frame rates then you will need a hub, of course but again, not sure what you would be actually doing to require this. When you are guiding the download from the guide camera is maybe 20KB every second at most. USB 2 supports 10000 times that rate. 

 

Rgrds-Ross

I would have assumed that for planetary (asi224), that usb 3.0 is almost necessary for the higher fps (60-150 for example).

 

At one point i switched the save location from local SSD to gigabit and the frame rate test at least, dropped dramatically, but i guess thats expected.

 

And yeah my whole setup last nite using a watt meter was only pulling around 1.25 amps at various times i looked.



#8 rgsalinger

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Posted 20 September 2019 - 03:39 PM

Unless you are doing high frame rate lucky imaging -- is exactly correct. Even then the CEM120 has a USB3 port. So, it's unclear to me why you need two of them. In the end, having an extra cable, carefully dangling is just not a big deal. 

Rgrd-Ross



#9 t-ara-fan

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Posted 22 September 2019 - 12:29 AM

  The reason one needs a powered hub - and I have one on my MX+ - is that you may need to run long USB cables to your computer. 

No.

The reason for a powered USB hub is so that the HUB can power other devices like a guide camera. 

It has nothing to do with the length of your USB cable.



#10 rgsalinger

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Posted 05 October 2019 - 08:40 AM

Yes. Try running a bunch of 12 foot cables from your devices to your computer and see how well your system runs. I never said the "ONLY" reason, I just said that rather than run long cables buy a powered hub. Maybe that wasn't clear enough, sorry for that. It's intuitively obvious to the casual observer that a powered hub provides (can you guess?) POWER.

Rgrds-Ross




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