Diy broken led panel fix

[RosettaStoned]

This is nothing ground breaking or original. I've seen a few videos on YouTube so I thought I'd give it a try. Found a broken morsen 1000 watt on eBay for $23. Did some research on what I needed after testing. All my stuff...
aluminum plate, 6 cree 36v cxb3070 35k + holders, 12 mono luxeon 3v 65k LEDs, thermal paste, connectors, wire, hardware, tools
matched and cut a new plate to mount LEDs on. Drilled all matching holes, removed heat sink and put on new plate.
Laid out all my LEDs and marked holes, drilled and tapped, then mounted with a little thermal grease.
breaktime.....
finished up mounting and wiring.

Gave a test try....
oops, one string out! Take apart and check everything.
there you go, fixed! It's real bright now
hopefully the girls appreciate the light.
I have another I'm going change as well, Mars hydro 300 watt 6 channel spectrum. Will post when it's done.

 

[DrPhoton]

Nice, i used to do the same thing with smartphones before they went completely sealed. Everything was modular and easier to repair. I had new smartphones for the whole family.

 

[RosettaStoned]

Thanks! Yes, screw buying new stuff all the time. Reduce, reuse, repurpose, recycle.

 

[DrPhoton]

Haha yes.

 

[Garrett]

How much did it cost for all the components?

 

[RosettaStoned]

About $260 with the two broken lights. Which will make two lights. I have 4 cobs and 10 mono LEDs left for the second build.

 

[RosettaStoned]

Here's the math...
the cobs run at 34 VDC @ 800 mA current, that's about 55% powered 5600 luminous flux. The monos run at 3 VDC @ 800 mA current, 80% powered 270 luminous flux.
34*.8=27.2 * 2=54.4 watts + 3*.8=2.4 * 4=9.6 watts
thats 64 watts a string * 3=192 watts being used.
Luminous flux...5600*6=33600+270*12=3240 total 36840 luminous flux.
luminous flux to lux...
E[SUB]v(lx)[/SUB] = 10.76391 × Φ[SUB]V(lm)[/SUB] / A[SUB](ft[/SUB]2[SUB]) [/SUB]
2x2 - 198,271 lux
3x3 - 132,180 lux
4x4 - 99,135
lux is not the best measurement but better than lumens, and I don't have a par meter.
i can not speak of how the light worked originally. I'm sure my spectrum is better being full. Plants use all light between 320-780 nm. Some colors are just used less efficiently than others, all are beneficial.
Next build tomorrow, I can prob get more information on the parts and specs to make a better comparison. Mars hydro to 4 cob 10 mono build.

 

[DrPhoton]

This is a better formula, though it does not really matter as units of luminous flux is the same as illuminance and luminous intensity. What your formula does is convert luminous flux into illuminance as a per square foot calculation. Not a standard unit used for measurement quantities and is quite useless. Although it would be a good assessment for the intensity of a certain surface area like you have done.

Ev(lx)*=*ΦV(lm)*/*A(m2)

What you are better off doing is using luminous flux, as its more valuable than a ft2 measurement. Or convert it using a conversion factor. For example. Although LED has different spectrum balance than other light sources, white LED is very similar to gas discharge. As such their conversion factor would be a good approximation.

Lets take for example 36840 luminous flux from your total light source value provided.

36840 x 0.014 = 515 PPF

One has to remember that a Quantum PAR meter that is typically used to measure lights, is not measureing in metres squared. This is because it is not designed for interior lighting with non uniform light distribution. So any single measurment made from such devices is practically useless for quantifying a light source

 

[DrPhoton]

Just for comparison. Your light has a photon efficiency of about 2.5umol per watt. Compared to the most efficient gas discharge which is 1.7umol per watt. Thats really good. Though no calculation is taken into consideration for the drivers and their heat loss.

 

[RosettaStoned]

Thank you! I was waiting for you to chime in. I should have just asked you a formula for it. DANGERDAN

 

[DrPhoton]

If you make another light just like that, run them side by side. It will be almost as powerful as a 600watt HPS for nearly 1/3 less energy. Thats about as good as it gets. I originally had thought you were just replacing with identicle parts, then realised you used different spec COB chips. Hence the really good efficiency.

I wouldnt be looking at getting another light with one of those, would just maintain and repair until its dead.

 

[RosettaStoned]

DANGERDAN it was 100 dual 5 watt diodes on a panel before. The Mars drivers are weaker at 665 mA and only two. This one won't be as good but still better than the original.

 

[DrPhoton]

Are they CC or CV drivers?, i assume CC as i dont see any current limiting devices.

 

[DrPhoton]

I assume also that the original fixture had optical lenses, i would think about adding some if possible as the unfocussed light will dramatically diminish efficiency.

 

[RosettaStoned]

Yes, they did. I can add them a little later
Cc drivers

 

[DrPhoton]

Love it

 

[RosettaStoned]

Me too, I was wonder the conversion factor for that. Thanks for that! Really solidifies doing it was a good idea and not a waste

 

[RosettaStoned]

Second light is finished. 4 cree cxb 36 V 3070s 35k, 10 luxeon 3 V 65k. It's running @ 665 mA, pulling about 110 watts. Luminous flux is about 22200 x .014= PPF 311 /110 watts =2.8umol a watt. Am I correct DANGERDAN
This one worked when I got it but I assume something is wrong if I got it for $20.

 

[DrPhoton]

Yea that wouldn't be far off. Of course taking into consideration the actual power consumption through the power supplies and drivers will lower that, due to efficiency losses. But that seems to be on par with what i would expect at that current level. But thats a good enough approximation.

 

[RosettaStoned]

Yes, of course. Those are not 100% efficient by any means, probably not even 90%