Hello to all
I have been perusing the forum now for some time, and only just recently registered.
I have a bit of a quandary.
Im looking to add a supplemental lighting system to an existing structure, and am hoping you all can be of some help.
I want to keep this on the cheap, as much as possible, and most importantly a modular type system where components can easily be replaced and/or swapped out as need be.
My thought is to use a common ATX power supply to run approximately sixty to seventy 5050 SMDs.
Output of supplys 12v leg is 11.95v (rated for 14amp), 3v leg is 2.97v (rated for 18amp). (actual volts measured with a FLUKE 87.
Ive worked with LEDs quite a bit in the past, but nothing of this magnitude, mostly with accent and homemade replacement lighting in cars, boats, motorcycles, etc.
My wiring will be a loop around the interior of the building, approximately 300ft. total. Using the loop I plan on connecting both ends back to the power source. I hoped to use 20-2 solid wire for the loop itself, and approximately 16in of 22-2 solid wire for the pigtails for the LEDs themselves.
To keep things as simple and off the shelf as possible, I have two options Im eye-balling.
1 Run the SMDs directly off of the 3.3v. leg of the power supply. At a rated draw of a bare 5050 being 20ma @ 3.2-3.4v Id have plenty room to spare, drawing (by my calculations) 1.2amp total draw.
2 use 5050 LEDs, prewired with resistors for automotive use, and running them off of the 12v leg of the supply. I have a couple of these, and have tested them with my FLUKE 87, finding their draw at about 45ma. Which would put 60 of them at 2.7amp total draw.
Ive used several internet based parallel/series LED wiring wizards, and see the options of running series/parallel setups. I dont want to use this, as if one bulb would fry, Id have a whole string of them out and have to test which ones a bad, etc. Im not a Christmas light fan .and really hate doing that.
Again, Im having my amp draw numbers of the LEDs confirmed, and will be able to post back with better numbers.
I lean toward using the 12v. leg of the power supply, as to me (guidance needed here as well), it would make more sense to push a higher voltage through the line right from the start, than the lower 3.3v.
Ill be using this simply as a kind of elaborate night light to accent the interior only (obviously) at night, and had planned on working out a simple photocell as an eye to control power to the power supply. HOWEVER, I also have several old power supplies for some Malibu lights laying around that already have photo cells incorporated into them. I know these put out (rated) 12v AC (11.8? actual), and know that using them would necessitate building a full wave bridge rectifier to convert the AC to DC.
The specifications for these supplies have long since rubbed off, but I do know that at one time I ran approximately twenty to thirty incandescent bulbs off of one of them following its specs so Im sure it could handle the current without any problem.
Ive built rectifier assemblies for a motorcycle in the past, but that was about nine years ago. I also would have no clue how much amp draw such a rectifier would handle, how to calculate that, or what components to use anymore.
So theres a lot of questions in there
Am I on the right track? What would my voltage drop be? With the loop I plan on using should I even be that worried about a voltage drop? (I believe computer power supplies are regulated, and in THEORY would internally compensate for any drop) Is my wire gauge sufficient enough? 12v or 3.3v leg? Computer Power supply vs. Malibu light supply w/ rectifier? Bridge rectifier designs?
Thanks to everyone in advance, any and all guidance is very much appreciated.
I have been perusing the forum now for some time, and only just recently registered.
I have a bit of a quandary.
Im looking to add a supplemental lighting system to an existing structure, and am hoping you all can be of some help.
I want to keep this on the cheap, as much as possible, and most importantly a modular type system where components can easily be replaced and/or swapped out as need be.
My thought is to use a common ATX power supply to run approximately sixty to seventy 5050 SMDs.
Output of supplys 12v leg is 11.95v (rated for 14amp), 3v leg is 2.97v (rated for 18amp). (actual volts measured with a FLUKE 87.
Ive worked with LEDs quite a bit in the past, but nothing of this magnitude, mostly with accent and homemade replacement lighting in cars, boats, motorcycles, etc.
My wiring will be a loop around the interior of the building, approximately 300ft. total. Using the loop I plan on connecting both ends back to the power source. I hoped to use 20-2 solid wire for the loop itself, and approximately 16in of 22-2 solid wire for the pigtails for the LEDs themselves.
To keep things as simple and off the shelf as possible, I have two options Im eye-balling.
1 Run the SMDs directly off of the 3.3v. leg of the power supply. At a rated draw of a bare 5050 being 20ma @ 3.2-3.4v Id have plenty room to spare, drawing (by my calculations) 1.2amp total draw.
2 use 5050 LEDs, prewired with resistors for automotive use, and running them off of the 12v leg of the supply. I have a couple of these, and have tested them with my FLUKE 87, finding their draw at about 45ma. Which would put 60 of them at 2.7amp total draw.
Ive used several internet based parallel/series LED wiring wizards, and see the options of running series/parallel setups. I dont want to use this, as if one bulb would fry, Id have a whole string of them out and have to test which ones a bad, etc. Im not a Christmas light fan .and really hate doing that.
Again, Im having my amp draw numbers of the LEDs confirmed, and will be able to post back with better numbers.
I lean toward using the 12v. leg of the power supply, as to me (guidance needed here as well), it would make more sense to push a higher voltage through the line right from the start, than the lower 3.3v.
Ill be using this simply as a kind of elaborate night light to accent the interior only (obviously) at night, and had planned on working out a simple photocell as an eye to control power to the power supply. HOWEVER, I also have several old power supplies for some Malibu lights laying around that already have photo cells incorporated into them. I know these put out (rated) 12v AC (11.8? actual), and know that using them would necessitate building a full wave bridge rectifier to convert the AC to DC.
The specifications for these supplies have long since rubbed off, but I do know that at one time I ran approximately twenty to thirty incandescent bulbs off of one of them following its specs so Im sure it could handle the current without any problem.
Ive built rectifier assemblies for a motorcycle in the past, but that was about nine years ago. I also would have no clue how much amp draw such a rectifier would handle, how to calculate that, or what components to use anymore.
So theres a lot of questions in there
Am I on the right track? What would my voltage drop be? With the loop I plan on using should I even be that worried about a voltage drop? (I believe computer power supplies are regulated, and in THEORY would internally compensate for any drop) Is my wire gauge sufficient enough? 12v or 3.3v leg? Computer Power supply vs. Malibu light supply w/ rectifier? Bridge rectifier designs?
Thanks to everyone in advance, any and all guidance is very much appreciated.