Building a Home Made LED

[Kukok]

clear now but if I use a 12V PSU? Can I drive n-lines of "-12V driver-3x4V LEDs"(parallel I think) or do I need a single 12V PSU for each driver-line?

Sorry for lacking basics...already have ordered a book to understand them.

 

[WeedIsGod]

3x4V = 12V
12VDC LED driver will work

Make sure that the current output of the LED driver is the same as the desired current consumption of the LED. Let's say you want to run each of your LED's at 350mA. Make sure the LED driver produces a constant current of 350mA.

Make sure the LED driver has 220VAC input. The only reason you would need a 12V power supply is if the LED driver didn't have one built into it already. Make sure that it does.

LED's are wired in series, not parallel.

Good luck.

 

[tenthirty]

The only thing I can add,

The plant senses the gradient of light as it travels down the plant.
This light gradient has an impact on internode length, stem and leaf growth. (maybe more)
I haven't tried it, so????

Be careful, you may not get what you wished for.

 

[jcmjrt]

Would it be wise for me to mix bins? In other words, all my WW are one bin, the CW are T6 U3, and the NW are yet another bin? I gather from your post that NW and WW are not available in T6 U3 like the CW are.

1) The max. light output of LEDs is at their maximum current (normally at 3000mA)...got it..

No trouble - each color has its own bin(s). I think that it should be grade A is best but they went the opposite direction

You may realize this but different colors within the same series of LEDs can have different max currents. Certainly different series of LEDs can vary on what is the max current. Usually the far end of the spectrum - say far red - will be driven at a lower current than the same series of LEDs say in royal blue. The only way to know for sure is to check the spec sheet.

 

[rrog]

Thank you for this. Many layers, this LED onion.

 

[hempfield]

clear now but if I use a 12V PSU? Can I drive n-lines of "-12V driver-3x4V LEDs"(parallel I think) or do I need a single 12V PSU for each driver-line?

Sorry for lacking basics...already have ordered a book to understand them.

Is very important that the current must be kept constant, otherwise bad things can happen. When running, the LEDs are generating heat. When the LED get's warm, the internal resistance vary and the LED burn more current, creating an avalanche effect.

You can power 4 LEDs connected in series to a constant voltage 12V PSU (for exemple a PC power supply), but you will never know how the current varies on that string of LEDs.

You can use a step-up converter like this http://www.ebay.com/itm/18103141056 you can connect more than 4 LEDs on a string, as this type of device handle to output more than 12V (up to 35V in fact) when powered by a 12V PSU. This driver have both voltage and current adjustable.

I strongly recommend you to use a dimmable/adjustable driver and to start driving LEDs at a lower current at the beginning to see if you heat sink can cool them enough. For this you will need some sort of thermometer to measure heat sink temperature next to LEDs and increase the current bit by bit until you reach o maximum temperature of 50 degrees Celsius.

You can also use this kind of driver http://www.ebay.com/itm/Non-Waterpr...10V-220V-Output-DC15-18V-2800mA-/261147686287 , which will run the LEDs at maximu, current of 2800mA. Notice that the minimal output voltage of this driver is 15V, which means you will have to connect at least 5 LEDs in series.

3x4V = 12V
12VDC LED driver will work

Make sure that the current output of the LED driver is the same as the desired current consumption of the LED. Let's say you want to run each of your LED's at 350mA. Make sure the LED driver produces a constant current of 350mA.

Make sure the LED driver has 220VAC input. The only reason you would need a 12V power supply is if the LED driver didn't have one built into it already. Make sure that it does.

LED's are wired in series, not parallel.

Good luck.

350mA current is used for 1W LEDs. Running an XM-L LED at that current will be a waste of money in my opinion.

Thank you for this. Many layers, this LED onion.

He he he, try to build a digital ballast for and HPS (or even a CFL internal ballast) by yourself and see how tricky it is When the LED industry will became more mature it will be much easy to just buy components as a kit and just connect them, as you can do with classical light sources.

Wonder what Thomas Edison would say about LEDs, now that one of his most important invention - incandescent bulb - became illegal due it's inefficiency (at least here in Europe) ...

 

[Kukok]

hempfield: thx for clearing things up. Although your link didn't show me anything I found this gadget:

http://www.ebay.at/itm/DC10-60V-to-12-80V-Step-Up-Converter-Constant-Voltage-Current-Power-Supply-600W

Is this the right thing? I should be able to use a mobile PSU. Did I get it right? The PSU output voltage as well as current must be lower then the wanted power and/or current output. That means that I should get a, lets say 12V PSU (because they are cheap and easy to get) with a maximum output current of 300mA, right?

what do you think of this driver? Doesnt it look cute? Due to the fact its a step up/down wouldn't be more versatile? The problem is low power it delivers I asume...isn't it?

 

[hempfield]

Yes, you are right, but this step up converter seems more powerfull (the one I tried to show is rated to just 100W and is half the price of this one : http://www.ebay.com/itm/DC-DC-100W-...-Mobile-Power-Supply-LED-Driver-/181031410566)

The power is calculated with the simple formula P=V*I, where V is the voltage and I is the current. So if you want to power 10 XM-L LEDs at 2000mA, you will need 10*3V = 30V and the total power consumption is 30V*2A=60W . If you use a step-up converter with 95% efficiency, you will need a PSU capable to give at least 100W (is not recommended to use it at full capacity to avoid damaging it).

If you read the specs of the step-up converter you will notice that :

600W Refers to the maximum power of the module under specific conditions, In the case of different input voltage, The maximum output power declined by the maximum input current limit. For example
Input Voltage 12V：Max Output Power P=12V*10A=120W
Input Voltage 24V：Max Output Power P=24V*10A=240W
Input Voltage 60V：Max Output Power P=60V*10A=600W

If the PSU provides 12V, that mean it must be able to give a minimum of 100w/12V = 8.3A . Any PC power source will give at least 10A on 12V output, so you can use such PSU to power the LEDs.

The small driver you found is cute indeed, but when you will want to use it at full power the heat will became a problem as it does not have a proper heat sink.

Please remember to set the step-up converter to minimal voltage and minimal current when first connect the LEDs to avoid burning them. An ammeter is mandatory to set the driver properly (and a voltmeter is recomended also to see if the driver has voltage spikes).

 

[Kukok]

Originally Posted by hempfield
Yes, you are right, but this step up converter seems more powerfull (the one I tried to show is rated to just 100W and is half the price of this one : http://www.ebay.com/itm/DC-DC-100W-C...-/181031410566)

Thanks for the info. already ordered. It seems that my journey into the world of HML-micro/pc-size grows has started

I think I am starting with 10 or 11 XM-Ls on a big heatsink from top and see. Maybe I will add a small second chain from the side with 4 reds 650nm or 2-3x ww XM-Ls on a seperate driver in flower.

I'll report back once I have got the thing working. Thanks a lot to you all for your support and motivation.

 

[xmobotx]

tremolo's diy micro led

 

[autojuice]

Stupid Q maybe...

Stupid Q maybe...

The Mean Well LPV-100-36 is rated 0-2.8A constant current,so you can´t tweek the Amps? If so you gotta ride those bitches (XM-L´s) hard? Did I get it right,and if so then the HGL series is better?

 

[xmobotx]

you could choose whichever driver you wanted within the parameters of the diodes you wanted to drive i.e. w/ xm-l you could drive them w/ 1A if you wanted or a full 3A {at least w/ the neutral} @2.8A they are being under driven ~just as many commercial fixtures

many would prefer to drive the diodes right up to their rating {and if you test temps and power diode to diode that will be fine} arguing they may as well get the full potential of the lamp

for those who do not choose to build their own; a pre-made lamp is a better choice

 

[rrog]

That's where I'm at. I had wanted to get a panel built for my buddy, and I can't seem to get this done fast enough. I may just point him toward a commercial unit. Then build the 5, yes 5, of the panels I worked out on my thread.

 

[tenthirty]

rrog, I would suggest that you build 1 and try it.

You could order all the parts from rapid led, have them there in a week and build it in an evening.

I know the hardest part is selecting the parts and pulling the trigger.

The meanwell 1750 driver is a good compromise and works well.
http://www.rapidled.com/mean-well-lpc-60-1750-constant-current-driver/

 

[medmaker420]

rrog, I would suggest that you build 1 and try it.

You could order all the parts from rapid led, have them there in a week and build it in an evening.

I know the hardest part is selecting the parts and pulling the trigger.

The meanwell 1750 driver is a good compromise and works well.
http://www.rapidled.com/mean-well-lpc-60-1750-constant-current-driver/

Are there any other companies besides rapidled that you have checked out by chance? I have had them bookmarked forever but wondering if any others are worth browsing through for diodes and parts.

 

[rrog]

Really? Could be built that fast??? I was thinking this would take dozens of hours or such. I had planned 50 leds per panel. Using the stickies to connect the leds to the sink, so that would buy me some time.

You're right about the selecting the parts and pulling the trigger. That's funny, it's so true.

I've been fascinated with the control boxes from Rives and Habeeb. Sharp stuff.

 

[hempfield]

50 XM-L per panel ? WOW, you gonna fry your plants if you will run the LEDs at full power.

 

[xmobotx]

Really?

maybe fab'n up the 'panel' for your friends micro would be a good 'confidence builder'

the advanced constructs such as rives does are a little daunting to me as well but; when you want multiple circuits on a single panel it can change the game

note; there are fixtures in this thread w/ multi drivers running 'bare' ~house AC>driver>diode circuit~
and it can be as simple as that the leads of all the drivers in parallel plugged in to the wall

 

[rrog]

Xmo- If this didn't take weeks to assemble, I'd maybe hit his timetable. I didn't want him waiting on me. It's not like I have huge time during the day but would carve away at it.

Hemp, I'd plan to run these at 2000mA so ~6W each. And of the 50, some of the CW or WW will be off, so the panel might be 250W. Shooting for 60W psf

 

[tenthirty]

Just so ya know, I'm running at 30 watts sq ft. doing better than 1g a watt.

My 80 watt (more or less) light bar, 18 leds. takes me about 1 hr to complete. First time was a little over 2 hrs actual assembly, months in research.

With the drop in price for XM-L's this is done for a little over 2 bucks a watt.