if you leave the far red on way too long it will actually inhibit flowering.
The far red thread
- Thread starter Rahz
- Start date
AquariusPanta
Well-Known Member
I don't believe inhibition takes place until after 2 hours of far red after lights out, from what articles I've read, so I'd be curious if we could get away with 1 hour of far red after lights out.
why ? for what advantage ? 5-15 min is pretty close to the dark side of twilight when far red is predominant..
AquariusPanta
Well-Known Member
It is, just offering food for thought, even if it's devoid of any nutrients 
so that makes you junk food ?It is, just offering food for thought, even if it's devoid of any nutrients
AquariusPanta
Well-Known Member
it's the best kind of food! especially when you're high! 
Yodaweed
Well-Known Member
After reading that article i am convinced auto's get nothing from far red light, read the last paragraph on photoperiodism, it says
However, day-neutral plants do not regulate flowering by day length. Not all plants use the phyotochrome system to adjust their physiological responses to the seasons.
Source: Boundless. “The Phytochrome System and Red Light Response.” Boundless Biology. Boundless, 08 Jan. 2016. Retrieved 12 Mar. 2016 from https://www.boundless.com/biology/textbooks/boundless-biology-textbook/plant-form-and-physiology-30/plant-sensory-systems-and-responses-184/the-phytochrome-system-and-red-light-response-701-11926/
Growlem
Member
Excuse if this is not the right place to ask this question, but the math of electornics and driver-calculation still gives me a headache.
I've ordered a 20-pack of 3 Watt 730nm LEDs. My grow room will be either 2 ft x 4 ft x 4 ft or 4 ft x 4 ft x 5 ft. I figure that about 10-12 LEDs evenly spaced will be enough.
Can somebody point me to a MeanWell driver that would be sufficient to power this number of IR LEDs?
I've ordered a 20-pack of 3 Watt 730nm LEDs. My grow room will be either 2 ft x 4 ft x 4 ft or 4 ft x 4 ft x 5 ft. I figure that about 10-12 LEDs evenly spaced will be enough.
Can somebody point me to a MeanWell driver that would be sufficient to power this number of IR LEDs?
Banana444
Well-Known Member
Do you have a link to the specs of the ones you bought?
.
you are correct that full autos won't benefit from the sunset far red flash, but to say that they get "nothing" from far red light is going too far. wavelengths up to the far red range are still active in photosynthesis (albeit at a much lower rate). Far red also effects seed germination and shade response (stem elongation to help find the sun).
There are also a number of strains (not related to ruderalis) that will exhibit auto symptons due to various other environmental stress and still react to far red flowering signal.
BOBBY_G
Well-Known Member
there are some cheap tiny drivers like in growmaus 3 led 1.5" aluminum bar vid that take a 5-12V DC cellphone wall wart down to proper specs, and then there are the full drivers that run on universal AC that are $11 and up.
Growlem
Member
http://www.ebay.com/itm/3W-5W-IR-LED-730NM-Far-Red-Infrared-LED-Diode-850NM-Lamp-Bead-Emitter-940NM-Chip-/201329723011?
Yeah, I was going to get multiple ones of the one that growmau5 uses if I can't find one that can run all the LEDs at once.
I figured it out how to choose a driver for regular COBs like the Cree ones but I still struggle with other stuff, like what's the difference between Constant Current and Constant Voltage driver.
BOBBY_G
Well-Known Member
constant current: will run all leds at a given power regardless of whether you "fill it up" or not. can only handle up to a certain number of cobs
constant voltage: will run any number of cobs in its spec. ie a 200W CV driver can run 20 cobs @ 10W, 10 cobs@20W, 5 cobs@ 40W, or 2 cobs @ 100W
constant voltage: will run any number of cobs in its spec. ie a 200W CV driver can run 20 cobs @ 10W, 10 cobs@20W, 5 cobs@ 40W, or 2 cobs @ 100W
Banana444
Well-Known Member
@Growlem
Meanwell lpc35-700 should drive up to 11 of those epistar 3w stars@ 700ma. Its looks like there are lots of options for drivers. I am pretty new at finding and matching my own drivers, someone else may have a better suggestion, i just ordered some cree xpg2 whites to play around with and make into a light for home lighting.
Meanwell lpc35-700 should drive up to 11 of those epistar 3w stars@ 700ma. Its looks like there are lots of options for drivers. I am pretty new at finding and matching my own drivers, someone else may have a better suggestion, i just ordered some cree xpg2 whites to play around with and make into a light for home lighting.
VegasWinner
Well-Known Member
You will need at least a lpc-60-1050a for that many diodes at 3w each is 36 watts and about 45 volts required to operate go to meanwell and look it up to verify.peace
VegasWinner
Well-Known Member
Those LDD drivers come recommended by stevesleds to power 5-6 diodes max so you would maybe need two or at least the 1000mA over the 700mA revommended. I am using the driver I offered because I will have a total of 15 diodes for 45w and 40v required minimum.
Growlem
Member
Looking into that.
Can you tell me what's the difference between these two models?
http://www.mouser.de/ProductDetail/Mean-Well/APC-35-700/
http://www.mouser.de/ProductDetail/Mean-Well/LPC-35-700/
Wouldn't it damage the IR-Diodes to drive them at 1050mA when it says 700mA in the specs?
Man, I didn't think I'd still have this much trouble figuring out the driver stuff, but for some reason I am completely lost right now when it comes to how many LEDs I can drive with, e.g. the Mean Well LDD-700H.
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@Growlem I've got 3 apc35-700 and 3 lpc35-700 and the differences aren't big, but there are a few:
apc is 15-50v
lpc is 9-48v
apc is IP42
lpc is IP67
The voltage range means that the apc can power slightly more leds, and the IP number shows that the lpc has a higher resistance to external objects and liquids (watertight down to ~1m). Also the apc runs hotter than the lpc by ~8 C. Might depend on the load, tho.
apc is 15-50v
lpc is 9-48v
apc is IP42
lpc is IP67
The voltage range means that the apc can power slightly more leds, and the IP number shows that the lpc has a higher resistance to external objects and liquids (watertight down to ~1m). Also the apc runs hotter than the lpc by ~8 C. Might depend on the load, tho.
VegasWinner
Well-Known Member
yes you are right. i read this article, very enlightening. ->http://www.ledsupply.com/blog/understanding-led-drivers/
What if I don’t have enough voltage? Using an LED Boost Driver (FlexBlock)
The FlexBlock LED drivers are boost drivers which means they can output a higher voltage than what is supplied to them. This allows you to power more LEDs in-series with a single LED driver. This is extremely helpful in applications where your input voltage is limited and you need to get
FlexBlock
more power to the LEDs. As with the BuckPuck driver, the maximum number of LEDs you can power with a single driver is determined by dividing the maximum output voltage of the driver by the forward voltage of your LEDs. The FlexBlock can be connected in two different configurations and varies when it comes to input voltage. In Buck-Boost (standard) mode the FlexBlock can handle LED loads that are above, below, or equal to the voltage of the power-supply. You find the maximum output voltage of the driver in this mode with this formula:
48VDC – Vin
So when using a 12VDC power supply and the XPG2 LEDs from above how many could we run with the 700mA FlexBlock? Your max output voltage is 36VDC (48-12) and the forward voltage of the XPG2 running at 700mA is 2.9 so by dividing 36VDC by this we see that this driver could power 12 LEDs. In Boost-Only Mode the FlexBlock can output up to 48VDC from as little as 10VDC. So if you were in Boost-Only mode you could power up to 16 LEDs (48/2.9). Here we go over using a FlexBlock boosting driver to power your LEDs in depth.
Checking wattage for High Power AC Input Drivers
Now with AC input drivers they give off a certain amount of watts to run so you need to find the wattage of your LEDs. You can do this by using this formula:
[Vf x Current (in Amps)] x LEDn = Wattage
So if we are trying to power the same 6 Cree XPG2 LEDs at 700mA your wattage would be…
[2.9 x .7] x 6 = 12.18
This means you need to find an AC driver that can run up to 13 watts like our MagTech 18W 700mA AC driver.
NOTE: It is important to consider the minimum output voltage of off-line drivers when designing your application. For instance, the driver above has a minimum output of 15 volts. Since the minimum output voltage is greater than that of our single XPG2 LED (2.9V), you would need to connect at least 6 of these together in-series to work with this particular driver.
Tools for understanding and finding the right LED driver
So now you should have a pretty good idea on what an LED driver is and on what you need to look for in selecting a driver with a power supply that is sufficient enough for your application. I know there will still be questions and for that you can contact us here at (802) 728-6031 or sales@LEDsupply.com.
We also have this Driver Selector tool that helps calculate what driver would be best by inputting your circuit specs.
peace. I ordered a lpc-35-700. according to the calculator that is all I need. thanks for the moment of clarity.