I'd like to make a very large array of 100-200 high power LEDs (as an energy-efficient grow light for my plants). I've been trying to work out the best way to do this. Let me know if I'm correct about this:
The trouble with a low voltage (<6V) parallel array, which I've made, is that one can only have so many LEDs due to the current. Even at 2A, it's only possible to have up to 100 20mA LEDs [(2A/0.1A per LED) = only 20 LEDs at full power].
So how do I get around this and have up to 100 - 200 of them? I was thinking that I could use a higher voltage and a different setup. I found this site, http://led.linear1.org/led.wiz, but was confused for several reasons.
1) The wizard doesn't mention the current, and isn't that important? or does the current not matter in such a series circuit. (I used 3.4V forward voltage of LED at 100mA, 36V DC source, and 200 LEDs in the array). According to http://led.linear1.org/led.wiz, that should work, but I'm confused about how. Try this: the wizard, with those settings, lets you have a potentially infinite amount of LEDs in the array, and apparently it will still work? Try 1000. It works. Is there some basic fact I'm missing about electronics (I'm a beginner)?
2) How come the resistors are on the downhill (-) side? Shouldn't they be in front of the LED? I thought that 36V coming at an LED would fry it.
Anyway, if anyone can answer those questions it would help me learn some important information about circuits.
The trouble with a low voltage (<6V) parallel array, which I've made, is that one can only have so many LEDs due to the current. Even at 2A, it's only possible to have up to 100 20mA LEDs [(2A/0.1A per LED) = only 20 LEDs at full power].
So how do I get around this and have up to 100 - 200 of them? I was thinking that I could use a higher voltage and a different setup. I found this site, http://led.linear1.org/led.wiz, but was confused for several reasons.
1) The wizard doesn't mention the current, and isn't that important? or does the current not matter in such a series circuit. (I used 3.4V forward voltage of LED at 100mA, 36V DC source, and 200 LEDs in the array). According to http://led.linear1.org/led.wiz, that should work, but I'm confused about how. Try this: the wizard, with those settings, lets you have a potentially infinite amount of LEDs in the array, and apparently it will still work? Try 1000. It works. Is there some basic fact I'm missing about electronics (I'm a beginner)?
2) How come the resistors are on the downhill (-) side? Shouldn't they be in front of the LED? I thought that 36V coming at an LED would fry it.
Anyway, if anyone can answer those questions it would help me learn some important information about circuits.
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