FlytrapCare Carnivorous Plant Forums

Hello all,
I have a project I am working on that involves examining the effect of different LED lights on plant growth (venus fly traps).
And I would like to compare "white" LEDs with "grow" LEDs, AKA Red/blue light. Because the plant absorption spectra is in the red and blue wavelengths. So anyway, I am planning to use 1 gallon jars as growth chambers to keep the environment the same for each plant, and I have found these LED ceiling downlamps to be the perfect fit for the lighting aspect. However, you cannot buy them with different color bulbs (you can get them with RGB LEDs though...) And I was wondering how hard it would be to replace white LEDs in these things with different color LEDs (Red, blue, orange and purple.)

Here is an image of the construction of the ceiling lamp:





and an image of the LED beads:


Now Ideally, I'd like different ratios of light in each of the grow lamps to determine what wavelength is more important for growing these plants, so I am actually looking at a 7W down lamp, using different ratios of red/blue/orange/purple light.

Red: 2.2-2.4v
orange: 3.0-3.8v and 700mA
purple: 3.4-3.8v and 350mA
blue: 3.2-3.4v and 350mA

First, is this possible, or should I not waste my time/money?
second, is this too difficult for me to attempt? Should I pay a professional? or can I try it myself without the possibility of burning my house down.

Could someone explain, or link me to an explanation about how this would all work? You'd have to do it in a way that is like telling your grandmother how it works. I understand the basics, but when it comes to diodes, and volts vs amps and things of that nature, I'm a little behind.

Well, the most different thing is the disasembeling process, the soldering is fairly easy, as long as it doent have to look perfect.

If all pretty much depends on the power supply, if using 12v (cheapest and easiest) u can calculate the amount of leds in serie as following (correct me if im wrong), voltage led 1+voltage led 2+voltage led 3 and so on, until u come out under 12v, only thing to consider is the amps, this has to be the same as far as im aware (thats why im ordered 350mA leds)

Then use this to calculate the resistor you need, http://led.linear1.org/led.wiz
Order a 5w resistor to be safe (i bought them for 22 eurocents each)


I see one problem in this setup, that it has to be 7 leds, this will cause you to use resistors that have to dissipate A LOT of heat, and it might be easier to go with a heatsink, its difficult to have a fixed amount of leds with different voltage and amperage ratings.

Since im not really into the Ohm's law stuff, i cant say for certain, but i will be following this thread.

well I plan on wiring them together in series, or parallel with other lights. They would be plugged into the wall (AC) So I don't know what effect that has on the wiring.

I did not know that about the amps of LEDs. Also did not know they came in different amp ratings. I will look around and get LEDs of all the same. Can you get red/blue/orange/purple LEDs with the same amps, AND same voltage?

The light is already wired and ready to use with white LEDs, so I was hoping I could just unsolder, and resolder my colored LEDs right on.

I am just going to order one of these lights, and take it apart. That way I will have a better understanding of what is going on in there, and I can ask some professionals, or at least some people with more experience wiring stuff than me. I'll keep the thread updated, and I am still planning on posting my results up, once I get the whole thing up and running.

U want to to have the negative and positive side directly connected to a wall socket? Without a LED power supply? I strongly advise you not to, unless u want to waiste huge amounts of energy (or start a fire).

Leds say the leds are 2v each, then if u have 120v (ac is 120 right?), u can have 60 leds in series without a resistor, or 7 in series with a 330 ohm resistor.

Same voltage for different leds is not possible since it lowers as the wavelength increases, same amps should be possible.
Do u have any ratings on the white leds, cause i can do some calculations for you.

Im still waiting for my last 5 leds to be in the mailbox, i also decided i wanted a fan on top of it cause i expect temperature to be about +40 degrees c above ambient temperature.
I ordered a thermostatic switch that turns on the fan as soon as it reaches 55, and shuts down as soon as it is 50 degrees c.

Well the lights come with an LED "driver" I am going to assume that is the equivalent of a power supply? The lights are made to be directly wired into your home electricity, which I assume is the same as wiring them to a plug, then plugging them in?

I'm making a lot of assumptions (as you can see). But I will definitely not be doing anything to put myself, or the other inhabitants of my complex, at risk.

I've gone ahead and ordered one of the 7W downlights, and I will update this thread once I take it apart, and see what's all going on in there.

I hope the white LED beads will be labeled well enough for me to determine their voltage and amps.

Thanks for the input thus far Sander. Can't wait to see your homebrew light.

Hey,

Assuming the leds you want to use are 1w to ( so roughly 3v and 0,35a), the led driver will suffice.
And if the leds are not labeled, u would be geared toward thinking they are 2.7-2.8 v, and 0,35a (thats what i run my white leds on).

I was worried u would solder cables to the leds + and - and attach them directly to a powerplug (without a driver).

Well, i hope ill receive my 5 last leds (had to order 5 uv leds more) and about one evening of soldering and wiring and it will be done =]