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What wire should I use for DMX + power?


Steven

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happylighting25 wrote:

Thank you Steve for the info on the DMX modules. They seem nice but very cheap. That always concerns me.

David

We at HolidayCoro.com have not only used over a thousand of these controllers personally but we've sold thousands and thousands of them. They have a failure rate of less than 1% and that' why we like them - they just work. You'd be hard pressed to kill them - they have short circuit protection and over current protection. Plus, if you want them to be 100% waterproof, just pop open the case and cover them with hot glue.
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dmoore wrote:

CAT5, IMHO, is the way to go with RGB. Cheap, easy to hook-up with both signal and power in a single cable, you can get "extension" cords in any color and length.
After investing in a bunch of 18-gauge, 4-conductor wire with waterproof connections, I can see that Cat5 was probably the better way to do it.

The only issue is the RJ45 connectors. They don't work well in the rain. A friend was always talking about the "green crud" the developed on the connectors when they got wet. He eventually found a solution involving a rubber sleeve and wire clamps. I use those RJ45-ECS waterproof connectors for my LOR network, but those connectors are bigger than the 3-channel DMX controllers! I need a better waterproof solution.

We at HolidayCoro.com have not only used over a thousand of these controllers personally but we've sold thousands and thousands of them. They have a failure rate of less than 1% and that' why we like them - they just work
I took one apart to solder directly to the pads for a ribbon fixture I'm working on. They are built very well.
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Steven wrote:

dmoore wrote:
CAT5, IMHO, is the way to go with RGB. Cheap, easy to hook-up with both signal and power in a single cable, you can get "extension" cords in any color and length.
After investing in a bunch of 18-gauge, 4-conductor wire with waterproof connections, I can see that Cat5 was probably the better way to do it.

The only issue is the RJ45 connectors. They don't work well in the rain. A friend was always talking about the "green crud" the developed on the connectors when they got wet. He eventually found a solution involving a rubber sleeve and wire clamps. I use those RJ45-ECS waterproof connectors for my LOR network, but those connectors are bigger than the 3-channel DMX controllers! I need a better waterproof solution.



I switched to running CAT5 as my "extension cords" in 2010 and here is what I've learned about CAT5 and water:

* Never, Never, Never let a CAT5 connection point (3 way splitter, 2 way coupler, etc) sit directly in standing water. If you have pooling water in your yard, gutter, flowerbed, etc - raise up the connection or completely seal it in another way.

* Spray the connection points prior to assembly with CorrosionX - this diaelectric spray was the best stuff I found when testing a bunch of different types. ZMan pointed out another "for industrial use only" one that had cancer causing agents but for consumer use, CorrosionX is the best I've found. Using CorrosionX, I've not had any problems with connections that didn't sit directly in water.

Thanks
David
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  • 1 month later...

After much thought, and input from various members of this forum, I have decided that Cat5 is the best choice for DMX+power. Furthermore, I have chosen the following pin-out for my DMX+power over Cat5:

Pin 1: DMX data+, because that is the standard.
Pin 2: DMX data-, because that is the standard.
Pin 3: +12v, because LOR also uses this pin for power.
Pin 4: +12v, because it was what was left over (see below).
Pin 5: +12v, because it was what was left over (see below).
Pin 6: Ground (power and DMX), because LOR also uses this pin for ground.
Pin 7: Ground, because that's the DMX standard.
Pin 8: Ground, because that's the DMX standard.

This pin-out has several advantages:

If a DMX light (with a built-in 3-channel DMX controller) is accidentally plugged into an LOR network, the (reduced) voltage from the LOR controllers may start the DMX controller, lighting the LEDs with the test sequence, but dimmer. This will tell me I plugged it into something wrong.

If the DMX+power network is accidentally plugged into an LOR controller, the over-voltage on the power (pin 3) line will probably cause the 7810 voltage regulator to safely shut down. An ELL on the network will probably not be damaged by 12v. The +12v on the LOR network input will probably not cause damage, because the RS-485 standard allows for voltages up to +12v.

Here's an example of a controller I hooked up with this pin-out:
IMG_3049.JPG

Here's what the connector looks like inside:
IMG_3048.JPG

Some of my thoughts on 4-conductor 18-gauge vs Cat5:

Cat5 advantages:

  1. Proper DMX impedance and twist. (Allowing long runs without interference.)
  2. Cheap and available everywhere.
  3. Much easier to wire plugs.
  4. Inexpensive plugs, available everywhere (like Home Depot).
  5. Easier and faster to connect and disconnect (assuming not using waterproof connectors).

18-gauge speaker cable advantages:

  1. Slightly lower resistance, thus higher power capability.
  2. Waterproof connectors are less expensive and easier (than an RJ45-ECS).
  3. Products from Seasonal Entertainment use this method.

I can work around the connector issue by splicing a Cat5 cable to a 4-conductor waterproof connector. My floodlights will be exposed to rain, so they will use the waterproof connectors. The strips around the windows will use RJ-45 connectors, but they will be shielded from the rain, and I'll spray some of that CorrosionX on them.

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  • 3 weeks later...
  • 3 weeks later...

come to think of it I dunno why I doubled the data lines... I shouldn't have done that... crap.

Sorry, but that had me LOL...

Maybe if I had golden wires... wire made of pure gold the current would travel flawlessly. =)

Silver is a much better conductor than gold.

...but you can't beat gold for corrosion resistance!

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Here is a good set of videos by DR. DMX, Doug Fleenor. He makes some of the best DMX interfaces out there.

Enjoy,

Steve

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first year with DMX and Corostars. I am very happy with David and his products (holidaycoro.com)! Dave was very helpful through chat and sent me videos pertaining to my problems which cleared things up perfectly. i ran my DMX and power over CAT5 like he suggests. using the power injection method was simple after i studied the videos before i tried to replicate them. my run was like this:

laptop-> dongle-> 30ft cat5-> power injector-> first rgb module-> 5ft cat5-> 2nd rgb ->5ft cat5, etc (for total of 8 rgb mudles/24 channels)

I saw no power loss from first to last rgb module.

these videos were very helpful,

http://vimeo.com/36677926

http://www.holidaycoro.com/kb_results.asp?ID=67

http://www.holidaycoro.com/kb_results.asp?ID=13

http://www.holidaycoro.com/kb_results.asp?ID=10

for my bad recordings of my displays/corostars/rgb strips (http://www.youtube.com/gotbluemilk1)

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