I am working on a new modular LED grow light. This thread will be a diary of my experience as I work through some of the many design problems.

Currently I am at the circuit design phase. Although I do not want to reveal too much of my design at this point I will provide some information that has guided my decisions.

The LEDs I will be using are from Lumiled. I am using the Luxeon K2s for the blue spectrum, and Luxeon IIIs for the red spectrum. The ratio of RED to BLUE (I will call this the R:B ratio from now on) is going to be 5:3 for the first board. This has more to do with cost than anything. Other threads get into more detailed discussions, but there no solid scientific evidence that I can see for any ratio - there are just too many unknown and variable factors at this time. My impression however is that BLUE LED light is at a part of the spectrum where the human eye is less sensitive. Actual luminous flux (SI unit is Lumen or lm) in BLUE LED light is deceiving because it may only be listed at say 23 lm on a datasheet, but that is corrected for the human eye - not the chemicals involved in photosynthesis (namely chlorophyll - look it up on Wikipedia). The third factor in choosing a 5:3 ratio is that RED light is more important in the flowering of the plant. More RED means more energy that the plant needs at flowering. I am totally open to comments or suggestions on this point in particular, as my science is sketchy at best.

As far as supply for each light module, the design will use a standard ATX power supply. Since this is a modular light, the wattage of the power supply is totally dependent on how many modules are used. I am hoping for a total power around 100 watts with 3 to 4 modules, and a light efficiency of about 80% of the power being used to produce light. To accomplish this, the design will incorporate LED driver circuitry for each color. This will also allow for future use of PWM drivers from a control circuit or computer which will be used to experiment on varying the ratio of RED and BLUE light.

I am by far no expert in lighting or growing. But I do have a strong electronics background and design circuits every day for my job.

Any input that you have, feel free to post it on this thread, but try to keep it relevant. Personal attacks should be done by IM.

Thanks for reading, and keep on toke'n. :rastasmoke:
budderlvr Reviewed by budderlvr on . budderlvr Modular LED Project I am working on a new modular LED grow light. This thread will be a diary of my experience as I work through some of the many design problems. Currently I am at the circuit design phase. Although I do not want to reveal too much of my design at this point I will provide some information that has guided my decisions. The LEDs I will be using are from Lumiled. I am using the Luxeon K2s for the blue spectrum, and Luxeon IIIs for the red spectrum. The ratio of RED to BLUE (I will call Rating: 5