Step 7: Results with Photos

<p>How do I calculate the current passing through the LED? for example, </p><p><strong>Watts Used by the System (High Setting)</strong></p><div><p>Red LEDs: 14.55V x 0.68A = 9.89W<br>Red LEDs with driver:16.13V x 0.68A 10.97W<br>Blue LEDs: 6.98V x 0.64A = 4.47W<br>Blue LEDs with driver: 10.24V x 0.64A = 6.55W</p><p>why the current for Red LED is 0.68 and for blue LED is 0.64</p></div>
<p>Me, confuse too, 3W red/blue led consume 600-700 mA from datasheet. math does not match</p>
<p>these lights don't get hot if you use them correctly, i have 7W hooked up with no heatsink and no fan...</p><p>you can angle these under the leafs if you want to even, remember less is more, it's all about the angles!</p><p>attach these arms to any plant pot ! check out my profile...</p>
<p>Hello, are you sure that you are using them with full brightness, and not in some sort of low power mode? I just built the circuit as described in the tutorial, and the LEDs get very hot. They consume about 1.44 Watt each, which would indicate a strong increase in heat. Could you tell me what you mean by &quot;<em>using them correctly&quot;? </em>Maybe a schematic or something.</p>
<p>hello huub88,<br>i meant as in a proper heatsink, check these out</p><p><a href="http://www.instructables.com/id/The-Plant-Shelf-lights-upgrade/" rel="nofollow">http://www.instructables.com/id/The-Plant-Shelf-li...</a><br>this heatsink can hold upto 20x1W high power led without needing a fan;</p><p><a href="http://www.ebay.com/itm/Aluminum-Heatsink-Cooling-for-8-x-3W-20-x-1W-LED-Light-/221487393871?pt=LH_DefaultDomain_2&hash=item3391ad6c4f" rel="nofollow">http://www.ebay.com/itm/Aluminum-Heatsink-Cooling-...</a></p><p>or individual ones</p><p><a href="http://www.ebay.com/itm/3pcs-1W-High-Power-LED-Heat-Sink-Round-Aluminium-Cooling-fin-Brand-New-/221682387576?pt=LH_DefaultDomain_0&hash=item339d4cca78" rel="nofollow">http://www.ebay.com/itm/3pcs-1W-High-Power-LED-Hea...</a></p><p>let me know if this helps, never go low power mode for plant growth, always full power :)</p>
<p>Not only the instructable but the conversation that it is going on down here. Excelent!!!! Thanks Everyone!</p>
What can you suggest for growing a citrus tree indoors during the late fall to early spring? <br>Is 24 Watts enough and is your current configuration acceptable?
Citrus trees require full sun. In full sun, my light meter reads G to H but you will need lenses for similar lighting more than a few inches from the LEDs. Narrow angle lenses provide greater light penetration. For a small area, 24 watts might be enough. What kind of citrus tree are you growing?
I have one meyer lemon tree which will grow its first fruit this winter and a persian lime that hasn't flowered yet despite being taller than the lemon
<p>this is a citrus tree with 1 x 1W led</p>
can u give me ebay address to buy LED 3W royal blue LED (445nm) and 3W deep red LED (660 nm)?
Sure no problem.<br>Royal blue LED:<br>http://www.ebay.com/sch/i.html?_odkw=royal+blue+led+3w&amp;_osacat=0&amp;_from=R40&amp;_trksid=p2045573.m570.l1313.TR0.TRC0.Xroyal+blue+led+3w+445.TRS0&amp;_nkw=royal+blue+led+3w+445&amp;_sacat=0<br><br>Deep red LED:<br>http://www.ebay.com/sch/i.html?_odkw=royal+blue+led+3w+445&amp;_osacat=0&amp;_from=R40&amp;_trksid=p2045573.m570.l1313.TR9.TRC1.A0.Xdeep+red+3w+LED.TRS0&amp;_nkw=deep+red+3w+LED&amp;_sacat=0
I would like to see the pictures.
Interesting review. Respect. But ... This is not the full range! My plants live a long time. They do not see the light from the window - only the LED. I use the 3 wavelengths, 445, 620 and 660 Nm. Important - the right combination of range, or a great result for the start and the finish of the collapse. You can use different combinations of range and get different results. I grow pelargonium, a caprice plant is very sensitive. However, 90% I was able to give the right light for the plants. <br>If you are interested, I can show my picture plants that all life under the LEDs.
Why did you use 4 deep red (660nm?) + 2 bright red (630nm?)?
does anyone know why when you use a power supply with higher or low voltage why the amps go up with higher voltage and down with lower voltage. It just makes it hard to get the amperage right.
your right I breadboard it and it works fine somehow I have been making it wrong.
In my grow light, changing the voltage had little or no effect on the current. You may want to check if you wired it correctly. I tested the circuit with a breadboard and measured the current before soldering.
The N-channel MOSFET used here has a different pin configuration from that of the NPN transistor.
do you know Apollo led grow lights from cidly? i think it is better than this.
Thank you hanlin_y for the help. one more question in the schematic the led are wired in series would it be ok to do the led in parallel?<br>Thanks.<br>
Theoretically yes but because each LED has a slightly different forward voltage, they will not have equal current so it's not a good idea.<br><br>If you are using an expensive current regulator and want parallel strings, you could use the circuit in this article.<br>http://www.ledsmagazine.com/features/6/2/2<br><br>No problem.
ok I am kind of rusty for the Constant Current driver do I need to use the about the same voltage as my led's need? led need 15volt so in put needs to be like 17volt is that right?<br>or is it ok to say use a 24volt power suply becase of the constant current driver?<br>anyone know.<br>
Yes, 17V works. If you have long wires and higher current, they can drop a bit more voltage. With this MOSFET, the power supply cannot exceed 20V but you can use a zener diode in circuit #3 in the page below. It will allow up to 60V.<br>http://www.instructables.com/id/Circuits-for-using-High-Power-LED-s/step7/Constant-current-source-tweaks-2-and-3/
What about the cost of the FAN? it looks like a normal PC fan so im guessing 12V 200ma? not a whole lot but another 2.4 watts
The fan and CPU cost $10 and you can get them at used computer stores or Craigslist. This one is 170 mA at 12V.
Interesting, but it still is not very clear to me about the two schedules. are you using both? or did i miss something?
ok I see now, the first schedule is a general one, the 2n is yr implementation of it
Just an FYI on the lighting schedule.<br><br>All plants have an internal timer that is controlled by the lengths of night and day. <br><br>to put it simply. Longer hours of day light tells the plant that it is time to grow. Also called the Vegetation cycle. <br><br>Shorter hours of day light tells the plant it is time to flower or reproduce. <br><br>The cycles for vegging are 18/6 or 18 hours of day light and 6 hours of darkness.<br>The flowering or reproductive cycle is 12/12 or 12 hours of day light and 12 hours of darkness.<br><br>I hope this helps clear things up for anyone with the same questions.
Right now, I'm growing vegetables with short daylight schedules. This article talks about how the timing and wavelength of light affects flowering.<br>http://plantphys.info/plant_physiology/photoperiodism.shtml
Pretty nice instructable. Might I ask the yields you have been getting using this setup?
Thanks you atrumblood! I just started fertilizing the vegetables and they grew a bit faster. They are still in their seedling stage. Seedlings should be fertilized after their true leaves appear. I will post some photos in the future to keep you up to date.
Thanks, I would appreciate that. I have a lot of experience growing indoors with hydroponics, but I have never used LED lighting before so I am interested in how well the LED's fair.
why is the supply voltage for red leds 6*2.5 V ?? You are only using 4
I think maybe there is a discrepancy between yr material list and what you are really using. I think it is 2 blue LED's (not 4) and in total 6 Red leds
Very nice! Had no idea a build like this would be so cheap to run.
Thank you!

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Bio: I'm a high functioning autistic who graduated in Electronics Technician Common Core and Food Technology at BCIT. My interests include utility cycling, recreational cycling ... More »
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