Number of Channels for Mega Tree

[nathancorson]

I am new to LOR and I am trying to figure out how many channels i am going to need for my 20ft Mega Tree this year. It wil have 24 strands of red, white and blue each for a total of 72 and i know ideally i would want to use 72 channels but was wondering if this would be too much for a 16 channel controller. The amps would barely work ( i tested the amps at .29 per string times 72 = 20.88). Or would i be better of using 24 cahnnels with 3 strings per channel. I will have about a 4.25 inch spacing between each strand.

[Denny]

nathancorson wrote:

I am new to LOR and I am trying to figure out how many channels i am going to need for my 20ft Mega Tree this year. It wil have 24 strands of red, white and blue each for a total of 72 and i know ideally i would want to use 72 channels but was wondering if this would be too much for a 16 channel controller. The amps would barely work ( i tested the amps at .29 per string times 72 = 20.88). Or would i be better of using 24 cahnnels with 3 strings per channel. I will have about a 4.25 inch spacing between each strand.

I assume you want each color to be controlled independently, in which case you would be using five channels per color (a total of 15 channels) with one channel left over. Is this right? I think almost everyone would recommend that you do a mega tree in multiples of 4 channels per color to make synchronizing to music much easier (based on the timing of the music, i.e., 3/4 time, 4/4 time, etc.)

As for the 20.88 amps for a single controller, if you are using the the 1602 series of controllers, I think Dan has said in the past that they have a little leeway built into them where you could exceed 20 amps for short durations of time. That is, if your electrical supply circuit is rated at 20 amps and you have replaced the fuses in your controller with 20 amp fuses. Also, keep in mind that the 1602 series is rated at 20 amps per side (or per 8 channels) if you run off of two different electrical circuits and eliminate the jumper between the two sides.

Sorry that I can't be of more help on the rest of your question, but not quite sure what you are trying to do as far as the channels and division of colors, etc.

[nathancorson]

I was thinking about having each red white and blue on a single channel. At this point i am just trying to figure out the best approach so i know what i need to get. My supply for the christmas lights is rated at 30 amp each on a dedicated breaker on a separate sub panel so amperage would only be an issue on the comtroller

[Denny]

Nathan,

If you use a 1602 series, the total amperage the board will handle is 40 amps, 20 amps per side. Using your numbers, 20.88 amps would only be 10.44 amps per side, so the board could handle the load with ease. If you use the PC version, it is rated at 15 amps per side and you could still do it safely.
Edit to add: Provided the boards have the heavy duty heat sinks. Also, there is a chart on the LOR web site, Support, that gives all the options as far as type of heat sink, model number of board, etc. that will give you the amperage breakdown by with or without heatsink, etc. that may be helpful to you.

[nathancorson]

I was thinking of using the CTB-16D contoller board mounted in a watertight Box

[Denny]

Same thing, just get it with the heavy duty heat sinks.

[Forest]

Nathan,

The rule of thumb that I use is to use 8 or 12 channels per color. The reason for this is that most music is either 3, 4 or 6 beats to a measure. I prefer 12 channels because it is divisible by any of the 3. On my 20 ft tree this year, I used a total of 16 channels. I had 48 strings of clear lights divided into 12 channels. I used 2 channels for a double snowflake that I used as my tree top and then I had a cross built into the structure of my tree that used the final 2 channels. Next year I plan to add 12 channels of red lights (48 strings). I also plan to add curtain strobes which means I will add a minimum of 13 channels.

Another option that you have is to do like Richard Holdman has done and feature one of your colors (i.e clear) with 8 channels and use 4 channels each for your other colors. This will allow you to do fades between colors and some rotation of your secondary colors while economizing on they number of channels required. This does rule out fine tuned spinning of your secondary colors and does not leave any channels for your tree top.

You can see my tree in action at mainchristmasinelgin.com. Look at the Polar Express video on the 2007 Display page.

Hope this helps,
Forest