Building a 9 RGB channel DMX Controller
with Power and Data over 4 Core Wire
I'm not an electrician, an expert in electrical things, nor do I have any training or degrees to qualify me as such. ;) I'm just a guy who figured out what works for his display. Take this information as such. If it works for you, GREAT! I've accomplished what I set out to do. If you see a problem with what I'm doing or have a question, please e-mail me. I'm always excited and willing to learn something new. I can't assume any responsibility for the outcome of your project if you chose to follow these instructions, or the fallout thereof. If you think I'm an idiot, kindly smile to yourself, click your "back" button three times, and have a nice day!
UNDERSTANDING THE BOARD
This is the basic board as it arrived. It has 6 points for mounting either with screws or standoffs
and all the connections for power and data are clearly labeled in english.
The board itself can handle voltages from 7V up to 24V making it suitable for most 12V lighting items. I've tested it with my Mighty Mini floods, the Rainbow Floods from Seasonal Entertainment, as well as the straight RGB "dumb" node strings and modules. The power uinput on the board uses two small screw terminals on the left side. They are labeled positive and negative so you know which wire goes where. The starting address of the unit is set with the on-board dip switches. Each switch has a numerical value listed below it, you just add them together to get anywhere from 1-512 channels. I also found an easy on-line calculator that allows you to input the channel number at it will give you the correct dip-switch configuration. The dip switch sets only the beginning address of the board, each of the outputs runs sequentially after that. So if the starting address is, say channel 100. The outgoing channels would be 100-127. The board comes with two XLR jacks, an incomming and outgoing, and you can definitely use the 3 pin XLR converters but the board also has solder pads for each of the three pins for a direct connection.
To avoid purchasing the converters and eliminate another possible loose connection I decided to use the direct solder pads. It also helps keep the board compact and will help it fit inside the enclosure easier. I attached two short jumper cables to the positive and negative pads then ran them bacck across the board to the 4 core waterproof pigtail that will input power and data. In the long run, I will likely have both the board and the power supply together in a single enclosure and will just connect the power directly.
Here you can see the power and data wires in their finished connection. The blue 12V positive wire attaches to the positive screw terminal on the board and the black 12V negative wire attaches to the negative screw terminal on the board. Our Red and Green Positive DMX and Negative DMX data wires are then attached to the "jumper" wires we soldered to the data pads.
Like I said before, when we put these into an enclosure I will probably house BOTH the 12V power supply and the controller together. I'll have a 120V A/C cord going out to supply A/C power to the D/C power supply. The "incoming" male plug will only connect DMX data to the board and power for the board will come directly from the included power supply.
Each of the "out" channels one through nine are labeled along the screw terminal blocks at the top of the board. The screw terminals are labeled Red, Green, and Blue respectively with the common positive terminal the furthest to the right. Here you can see the connection of the outgoing 4 core common positive pigtails, exactly the same as the small DMX decoders we used last year. This will allow us to use this board with any of the display elements in exactly the same way as the smaller $6 DMX decoders maintaining the interchangeable advantage of the "system." Hopefully keeping it simple and uniform throughout will eliminate problems down the road.
The most common "go-to" product in the DIY community is the Keptel Demarc cable box enclosures. They are inexpensive, weatherproof and convenient. The source many of us used to order these enclosure over the last couple of years closed up shop so sourcing on them has become more difficult and the price has gone up. You can still find them on eBay and through various vendors but the best price I've been able to find on them is through an overstock website called Excess Supply. The enclosures I'll be using will most likely be the AFL Telecom CG-2000-A. They will easily fit these boards with enough room to spare for the power supply I hope! I am going to continue to search for other options and update this page as I go.
PROOF OF CONCEPT RGB MEGA TREE
The setup shown in the picture is nearly ideal for a mega or half mega setup and is what I'm putting together for several other decorators for the comming 2012 season. Each of the node strings pictured are 50 nodes long. According to the specs each node uses .3 watts when lit white. For a 50 node string that equates to 15 watts total. Now doing our calculations for watts, volts, and amps we know that a 15 watt draw at 12 volts means we need 1.25 amps of power. If the math challenges you, I found an on-line calculator that will do it for you.
The board is specified to be able to handle up to 15 amps and for my purposes I will stay inside of that limitation. I know other users have successfully used them well above that limit and have designed solutions to deal with the challenges that creates. In keeping with the spirit of DIY simplicity it just isn't worth it to me. If I need to draw more than 15 amps, I'll just purchase another board or use one of the smaller decoders.
Whether you are planning an RGB mega, an affordable flood light controller, a basic RGB arch, or even a mini tree row, these controllers offer a nice middle ground between traditional light strings and going full digital RGB pixels.