I have a led engin 40W rgbw led that i'm building a fixture around, and i've been puzzling about how to do some of the wiring. Eventually i'll have several of these fixtures, each with one led, and i was hoping to daisy chain power and data, preferrable on one cable. What is the best wiring to use?
The specs for the LED, 700ma per channel, 12VDC max on each, except red is 8v max. The fixtures will be dmx controlled, and powered by 12v. The idea is to have two connectors on each fixture, and in and an out. The IN connector carries power and dmx data to the 4ch constant current controller, and that sends power to the leds in response to dmx. The OUT connector is there so i can connect it to another fixture, so with one single cable, i get power and data to it without having messes of cables everywhere.
The main problem i see, dmx needs to be twisted pair, that means cat5 (i want to avoid standard dmx cable). Cat5 is usually 24 gauge, which won't carry enough current.
What i want to do is have the power going to the IN connector sent to that fixtures led controller and also wired to the OUT connector, that way, each fixture is wired to the power in parallel.
I thought that i might be able to use TWO twisted pairs on the cat5 for power instead of one (one pair for positive, one pair for negative). Do you see any problems with doing that to get around the current limits of a single 24gauge wire? I'm not sure what gauge equivelant that would make it so that i can tell how much current can be use that way though.
Here is where my electronics experience lacks... If i have power wired this way (power in wired in parallel to power OUT), will the entire path for power be carrying the full load of all of the fixtures that are connected together? In other words, two fixtures will have eight LEDs (two red, two green, two blue and two white). Each needs 600ma (the LEDs are rated to 700mA, but the controllers will be sending 600mA constant current). eight times 600mA is 4.8 amps. Do all of the power leads need to carry 4.8 amps when they're all hooked this way?
A similar question, the controller is hardwired so it has four "-" outs and one "+". Since the + will be hooked to the + of all four channels on the LED, is it carrying 4*600mA, while the "-" ones are only carrying 600mA each?
Also, if i'm reading right, people generally omit the ground connection when sending DMX over cat5, is that right? Are signal problems common when doing it this way?
The last question, the controller i am using has dmx in, but no dmx out. The manufacturer says it can be used for both. This seems more and more common these days. But i keep seeing in places that you should never ever Y a DMX signal. But if i hook the DMX on the LED controller both to the DMX coming in and to the DMX of the next controller, isn't that exactly what i'm doing?
Thanks for any help!
RobT
The specs for the LED, 700ma per channel, 12VDC max on each, except red is 8v max. The fixtures will be dmx controlled, and powered by 12v. The idea is to have two connectors on each fixture, and in and an out. The IN connector carries power and dmx data to the 4ch constant current controller, and that sends power to the leds in response to dmx. The OUT connector is there so i can connect it to another fixture, so with one single cable, i get power and data to it without having messes of cables everywhere.
The main problem i see, dmx needs to be twisted pair, that means cat5 (i want to avoid standard dmx cable). Cat5 is usually 24 gauge, which won't carry enough current.
What i want to do is have the power going to the IN connector sent to that fixtures led controller and also wired to the OUT connector, that way, each fixture is wired to the power in parallel.
I thought that i might be able to use TWO twisted pairs on the cat5 for power instead of one (one pair for positive, one pair for negative). Do you see any problems with doing that to get around the current limits of a single 24gauge wire? I'm not sure what gauge equivelant that would make it so that i can tell how much current can be use that way though.
Here is where my electronics experience lacks... If i have power wired this way (power in wired in parallel to power OUT), will the entire path for power be carrying the full load of all of the fixtures that are connected together? In other words, two fixtures will have eight LEDs (two red, two green, two blue and two white). Each needs 600ma (the LEDs are rated to 700mA, but the controllers will be sending 600mA constant current). eight times 600mA is 4.8 amps. Do all of the power leads need to carry 4.8 amps when they're all hooked this way?
A similar question, the controller is hardwired so it has four "-" outs and one "+". Since the + will be hooked to the + of all four channels on the LED, is it carrying 4*600mA, while the "-" ones are only carrying 600mA each?
Also, if i'm reading right, people generally omit the ground connection when sending DMX over cat5, is that right? Are signal problems common when doing it this way?
The last question, the controller i am using has dmx in, but no dmx out. The manufacturer says it can be used for both. This seems more and more common these days. But i keep seeing in places that you should never ever Y a DMX signal. But if i hook the DMX on the LED controller both to the DMX coming in and to the DMX of the next controller, isn't that exactly what i'm doing?
Thanks for any help!
RobT