Epistar/BridgeLux/noname: A red LED Under The Microscope - Real and Electronically

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patrikantonius

Active Member
I think there is some sort of constant current regulation. In the specifications it is written "Constant current specific to each LED". The constant current regulators might be SMD chips embedded onto the PCB, such as the LM3404HV or something like that.
Connecting the LEDs directly to a DC power supply with resistors is far from optimal in my opinion. Depending on how much the voltage drops when load is applied, there could be heavy losses in efficiency in the resistors.
 
Gastanker

Gastanker

Well-Known Member
patrikantonius said:
I think there is some sort of constant current regulation. In the specifications it is written "Constant current specific to each LED". The constant current regulators might be SMD chips embedded onto the PCB, such as the LM3404HV or something like that.
Connecting the LEDs directly to a DC power supply with resistors is far from optimal in my opinion. Depending on how much the voltage drops when load is applied, there could be heavy losses in efficiency in the resistors.
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I'm pretty electronic ignorant, thank you. SMD - that's what I'm seeing. Are they capable of finely tuning the current as well as a specific driver? I assume so huh? Can't be that difficult to accurately shave a few mA from the incoming current. Blah, I feel I need to enroll in some electronics classes. What would be the equivalent of an SMD that doesn't need to be surface mounted but instead just inline like you can do with a resistor?
 
Rasser

Rasser

Active Member
patrikantonius said:
Aren't all panels using reflow soldering? I know hans' panel does, and plantphotonics' as well. I wasn't aware of any other alternatives to stick SMD LEDs to a thermal interface/MCPCB.
As for the lens, the LEDs are already focused to 80° so lenses should not be necessary. Plus a lens is never 100% transparent, sometimes as much as 15% of the light is lost in the lens.
What you're missing though is that it uses the most efficient LEDs on the market so I guess it should be much better than the Apollo. I've personally tested none of those but from the technical specs the rhinogrow seems definitely a killer. I would also add that the LEDs are spread over a much larger surface with a massive heatsink which seem to allow passive cooling which I think pretty neat.

As for the price, of course it is expensive. But it's made from quality components and the assembly seems great so it kinda justifies the price. I think it is can be put in comparison with plantphotonics and hans panels (both 3 using very high quality components) which are in the same kind of prices.
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Well the first picture in this thread is of such alternative, here is another from the Apollo 6 thread:

6 screws is adding pressure to the round top plate witch add pressure to and hold the lenses witch fix the LED and the pcb firmly to the heatsink,
a thin nonconducting tape is covering the sink and is preventing the LED back side to make a short between each other.




Okay had i hunch on that but there was no specs on the site.

With this type of panel, like Psuagro's having a room that fits well, with mirror like walls, and a even canopy is decisive in what the results will be.
It's not so much with 30-60° lenses, there you can grow in the middle of a large room with no walls, and a uneven canopy is forgiven more, from the fact
that the light is hanging higher to get coverage but is more concentrated, eliminating the big difference in PAR reading at the top of the plant and low down,
just as there is no difference in getting a sun tan from the street level or on the rooftop of a high building.

LED's with lenses of 120°+ loose radiated power very quick, I think its the same phenomenon as in a blasts:

Multiply the psi number with 100 and it looks like PAR measurements.

 
Rasser

Rasser

Active Member
FranJan said:
Hey PetFlora I'm just playing with you a bit since I've seen you be a big advocate for 630nm in some conversations. I'm more of a 660nm person so your 660nm suggestion made me chuckle a bit, so I decided to have a little fun, that's all. And neutral white or not, I would have to see the data sheet on the LED if I was depending on a white LED to cover or assist with specific spectrums, especially if it's a phosphor based white diode which can be all over the RGB (and Y) spectrum it seems. Something like a Neutral White Cree XR-E is terrible for 630-660nm, though I would assume there are better Cree models to choose from. Peace and Happy Growing PF!
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That reminds me of this Violet 30W LED chip I saw the other day.
30Watt HIGH POWER LED
Emitted Color ​
Violet ​
Chip size
 36mil Blue
Forward Voltage​
32-36V​
Forward Current​
1050mA​
Luminous Flux​
900LM
​
View Angle​
About 140°​
Quantity​
1 PCS​

This is not UV. It is mixed color from blue chips and fluorescent material. Not directly from the chips.


I this a plant grow chip? its hard to tell without a spectrum, it could sound perfect, but what about the ratio, I think violet is 50/50 red and blue,
The perfect veg-Chip?
 
Rasser

Rasser

Active Member
Gastanker said:
The rhino grow controls current regulation to the various different diodes via resistors on the PCB correct? How much of a difference does controlling current with the driver make versus controlling it at the diode with resistors? I've seen many people using resistors instead of constant current drivers. Any chance you could break down the pros and cons in layman terms between the two for me Rasser?
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The pros with resistors is that there are cheap, and comes in range from 0.01 ohm to 20 mega ohm, and can handle wattage from 0.1W to 1000xx kilowats(heating elements)
The pros is also it's job turning electricity into heat and making the voltage over it drop.

Only cons is its job turning electricity into heat, for thats not what you want in a closed box.
Old TV sets from the 70 and 80 used one main psu and then used heavy wattage resistors to drop the voltage to the tubes and components in general
so they got very hot and the longevity was effected.

These days with switch mode power supply's and digital tech there is not much waste, and resistors are used to regulate milliamps.

The Pros with constant drivers is they turn up the voltage until it can measure a draw of the rated current and stops there,
if one of the LEDs in a string burn out and short then the driver will turn down the voltage, and spare the LED's from overload.


What one chose to use depends on many factors, if your going with a single PC PSU and using the +12V line
you can connect that to a string of 5 red LED's running 2.35V and a 5W ~0.1ohm resistor and your running safe
and you can keep adding more string of 5 LEDs and a resistor in parallel with each other
to make a el-cheap-o grow light, the 5W resistor cost ~the same a 1 led.
(it will draw a lot of current using only 12V so the cables has to be thick, in this example)
 
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patrikantonius

Active Member
Yeah rasser obviously this kind of panel works best with SOG/SCROG techniques, but is it wrong to adjust the growing technique to the light? I don't think it is :) We can't really blame the panel for not behaving like an HID is what I mean.
 
Rasser

Rasser

Active Member
I think the images speaks for them self. :-)




I had read that LED was photo sensitive but I had not idea that they where fucking solar panels, cool ! :bigjoint:
I wonder what MajorCoco & Gastanker's ~100W would produce when exposed to full sunshine.
 
Rasser

Rasser

Active Member
One of the reasons I bought the Osram LED's was to see if I could avoid reflow soldering and mount them somehow just as its done on the Apollo panels.
Then an hour ago I noted this 15 LED module PCB, designed for reflow soldering, and I thought why not drill holes and mount the LED up side down.




Making a Micro UFO - A 3x1W pcb was to be used as a prototype to test the concept.
The heatsink already have nonconducting sticky tape on it.
330mA and temps

 
Rasser

Rasser

Active Member
patrikantonius said:
Yeah rasser obviously this kind of panel works best with SOG/SCROG techniques, but is it wrong to adjust the growing technique to the light? I don't think it is :) We can't really blame the panel for not behaving like an HID is what I mean.
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Why buy a panel at 650$ that then sets demands.

And another thing the power supply, looks special designed, could be hard to find at replacement especially if the company go bust.

Comparing an Apollo 10 and this panel is like night and day to me.

The A10 has 10 individual modules that can be changed by removing 6 screws and a plug, once your are inside the box.
A module has 15 LEDs that easily can be changed is seen in post 1 the same with the lenses, you can mix them if you want.

The A10 has 5 individual drivers making sure the hole panel can fail, and replacement driver can be found on e-bay cheaply.

The A10 makes a lot of noise compared to the other thats for sure.

And btw I my self bought a Apollo 6 panel that sat demands, I had to buy a tent and place it in another room to use the light,
the demand that the panel was requiring was earmuffs :-) like my 120W UFO did.
 
FranJan

FranJan

Well-Known Member
Rasser said:
I this a plant grow chip? its hard to tell without a spectrum, it could sound perfect, but what about the ratio, I think violet is 50/50 red and blue,
The perfect veg-Chip?
Click to expand...
Is it a blue LED with red phosphor, or a blue LED sitting in epoxy impregnated with a red or violet phosphor? There is a way of making white LEDs by taking a blue LED and coating it with a yellow phosphor. This will produce a very low CR white light. I think the spotlights I use make white light by having a blue diode in a yellow phosphor rich epoxy and I'm wondering if this chip you've found does it's violet color this way. Either way if they push out the right spectrums at adequate lumens, then they are what we want, right?

And I was wondering if anyone has ever seen a white light LED that uses a UV LED in place of the blue LED? I've read in textbooks that you can make a white LED this way, but have never seen one.

Rasser said:
I had read that LED was photo sensitive but I had not idea that they where fucking solar panels, cool ! :bigjoint:
I wonder what MajorCoco & Gastanker's ~100W would produce when exposed to full sunshine.
Click to expand...
What,what what! So we can feedback our light?
 
Rasser

Rasser

Active Member
FranJan said:
Is it a blue LED with red phosphor, or a blue LED sitting in epoxy impregnated with a red or violet phosphor? There is a way of making white LEDs by taking a blue LED and coating it with a yellow phosphor. This will produce a very low CR white light. I think the spotlights I use make white light by having a blue diode in a yellow phosphor rich epoxy and I'm wondering if this chip you've found does it's violet color this way. Either way if they push out the right spectrums at adequate lumens, then they are what we want, right?

And I was wondering if anyone has ever seen a white light LED that uses a UV LED in place of the blue LED? I've read in textbooks that you can make a white LED this way, but have never seen one.
What,what what! So we can feedback our light?
Click to expand...
One of the pros of the violet chip could be that since the red is made from blue the chip is not as temperature sensitive as a normal red LED are.


It has off course no practical use as a electricity generating device, unless its some weird emergency, where Gastankers only option
for charging his phone during a black out is to rewire his chips and connect them to a 12 car USB charger :-)

But it looks like the chip is sensitive to the wavelength they are designed to radiate,
I placed the 660nm chips under the RGB floodlight and the voltage measurements was: Red = 8.2V Green = 4.6V Blue = 2.3V while running single colors.

So maybe one can make a LED grow light PAR meter out of 660nm and 450nm LEDs, :-)
I wonder what the spectrum response looks like, does it mirror the radiated spectrum.
 
FranJan

FranJan

Well-Known Member
You know what would be great? If you can use LEDs to confirm or measure the wavelength of other LEDs. So when the guy in China sends you 10 650s instead of 10 660s, you have some way of knowing the diffrerence without running to a lab or buying expensive equipment. That would help stop some of the almost criminal behavoir of some of these merchants. You have to take these sellers at their word most of the time and a cheap, accurate way of testing their LEDs would be a godsend IMHO.

Keep up the good work Rasser. I learn more about LEDs from you than most textbooks, so thanks again Professor!
 
PetFlora

PetFlora

Well-Known Member
FranJan said:
Hey PetFlora I'm just playing with you a bit since I've seen you be a big advocate for 630nm in some conversations. I'm more of a 660nm person so your 660nm suggestion made me chuckle a bit, so I decided to have a little fun, that's all. And neutral white or not, I would have to see the data sheet on the LED if I was depending on a white LED to cover or assist with specific spectrums, especially if it's a phosphor based white diode which can be all over the RGB (and Y) spectrum it seems. Something like a Neutral White Cree XR-E is terrible for 630-660nm, though I would assume there are better Cree models to choose from. Peace and Happy Growing PF!
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No worries. I'm an easy mark. Have just enough knowledge to get us ALL killed :shock: I am only following the info laid down by SX on IC grow site. I C/Pd it into my journal. It's a bit long, lots of graphics. Hope you will check it out and report back, there and/or here. Page 11 post #102
 
Rasser

Rasser

Active Member
Hi

I was looking at one of those IP67 30-100W LED floodlights housing and thought,
that could easily be turned into a big water cooling head for LED chips, make the front plate thick enough
and you can drill and make threads without going through to the water.

Running 100+ watts on this in a little box should be no problem if the radiator is outside the box.
 
PetFlora

PetFlora

Well-Known Member
Does this forward the cause? http://www2.electronicproducts.com/LED_cooling_liquid_techniques_and_next_gen_solutio ns_highlight_coolingZONE_12_conference_in_August-article-newspo01_16jul2012-html.aspx
 
B

bbspills

Well-Known Member
Rasser, did you do any temp tests running 2 of the 660nm 10W chips on the CPU cooler?

I am about to mount 4 total chips on two CPU heatsinks and was wondering if you had any figures. The heatsinks were pulled from servers and have copper plating, so hopefully they should do the trick pretty well.

Also, when you were benching your temp tests, heat sinks are not nearly efficient when the fins are facing downward as heat rises, thus making the fins less efficient.

Here is a report that shows thermal effectiveness with LEDs and heatsinks positioned differently

http://bridgelux.com/assets/files/AN10_Thermal_Management_of_LED_Arrays.pdf

So if you plan on directing the light downward you should see some better results from the heat sink.
 
Rasser

Rasser

Active Member
Hi, I haven't had the time/priorities has chanced to play with any LED grow light related stuff lately, even thou I have received the
Apollo panel I ordered to use in a DIY grow light and 4 blue 10W 30V chips and drivers, and have still not made the 3 module of 4 10W 660nm LED chips.

bbspills>Good doc, thanks I save it for later.
"Also, when you were benching your temp tests, heat sinks are not nearly efficient when the fins are facing downward as heat rises, thus making the fins less efficient.
So if you plan on directing the light downward you should see some better results from the heat sink. "

My heatsink was active cooled by the fan, so the test from the doc can't be used to compare, I think., is that not passive only.
 
N

Nroe

New Member
Rasser said:
Grabbed some more pictures, this time with and without power to the LED's
I felt like writing 'no shit' above the ID text on the red and blue leds :-)

So only the red and far red are looking the same, so maybe the other LED's are from someone else than Shenzhen Hanhua opto Co.

The red LED with power on looked very nice in the microscope but was not possible to capture on the phone.
The far red LED is basically invisible except when running full power.
Click to expand...
I would tell you.. No bridgelux chip here... Its epiled chipp not bridgelux, bridgelux different than other
 
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