DIY LEDs - The write-up
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kcress
New member
Whoa...
Hooking up the LEDs in series will require the first to have it's NEG hooked to the next one's POS and so on..
Then to run it you hook across the two outer POS and NEG pads with your source.
shackscs; Each LED needs it's forward voltage over-come before any current flows. If you don't have at least that much voltage.. They might barely still glow in a dark room.. or not!
Personally it sounds like you don't have enough voltage since 3 batteries are good for 4.5V and each LED needs ~3.5V. As soon as you have two in series you're below the required head voltage.
Plus it sounds to me like you have them mis-wired to boot unless you have what I described above.
timmmysli; I am still most impressed with your tube-in-a-tube design. I have a hard time imagining it NOT keeping the LEDs cool enough with the flow shown in the movie as most designs require large heat sinks because there is NO forced air flow. Forced air flow makes any sink many, many times more effective.
Hooking up the LEDs in series will require the first to have it's NEG hooked to the next one's POS and so on..
Then to run it you hook across the two outer POS and NEG pads with your source.
shackscs; Each LED needs it's forward voltage over-come before any current flows. If you don't have at least that much voltage.. They might barely still glow in a dark room.. or not!
Personally it sounds like you don't have enough voltage since 3 batteries are good for 4.5V and each LED needs ~3.5V. As soon as you have two in series you're below the required head voltage.
Plus it sounds to me like you have them mis-wired to boot unless you have what I described above.
timmmysli; I am still most impressed with your tube-in-a-tube design. I have a hard time imagining it NOT keeping the LEDs cool enough with the flow shown in the movie as most designs require large heat sinks because there is NO forced air flow. Forced air flow makes any sink many, many times more effective.
james3370
Premium Member
when i had problems w/ mine (chineese knock-offs) i soldered a piece of wire on each side of the LED & used a pair of AA batteries to test each LED individually. i found (2) that the polarity was reversed from what was indicated on the starboard.
once i rewired the loop accordingly, it fired up
my advice would be to test each led for polarity & to be sure it works before wiring a string of them....that kills 2 possible defect scenarios in 1 step. then if it doesn't work, you have a power or wiring issue
once i rewired the loop accordingly, it fired up
my advice would be to test each led for polarity & to be sure it works before wiring a string of them....that kills 2 possible defect scenarios in 1 step. then if it doesn't work, you have a power or wiring issue
Hi all - well, I figured it was time for me to do my LED project, which was to build LED "spotlights" for "shimmer" supplementation for my T5s so I could get rid of my MHs once and for all! 
I built two spotlights, each with three cool white LEDs. The LEDs were mounted on CPU heatsinks.
I found the perfect bracket (except for it's not stainless steel at my local Lowe's) that allows the spotlights to be mounted on a vertical surface, but have the spotlights at a 45 degree angle.
I then mounted both spotlights into the corners of my canopy, aimed towards the center of the tank.
I also shot a video of the LEDs in action so you can see the shimmer they create. Especially with the daylight T5s on, you might think the shimmer is barely noticeable, but it's there. It's YouTube's compression that makes the shimmer tough to see!
http://www.youtube.com/watch?v=TVUfIatAXoE&feature=channel_page
I built two spotlights, each with three cool white LEDs. The LEDs were mounted on CPU heatsinks.
I found the perfect bracket (except for it's not stainless steel at my local Lowe's) that allows the spotlights to be mounted on a vertical surface, but have the spotlights at a 45 degree angle.
I then mounted both spotlights into the corners of my canopy, aimed towards the center of the tank.
I also shot a video of the LEDs in action so you can see the shimmer they create. Especially with the daylight T5s on, you might think the shimmer is barely noticeable, but it's there. It's YouTube's compression that makes the shimmer tough to see!
http://www.youtube.com/watch?v=TVUfIatAXoE&feature=channel_page
lilmonster
New member
That's a great idea.
What are you powering it with?
What are you powering it with?
Thanks! They're exactly that. Soundwave and I emailed each other, and we both agreed that CPU heatsinks would be perfect for my application. The heatsinks I went with came with an 80mm fan, but after installing the heatsinks into my canopy, I decided I didn't need the fans. The fans I have in my canopy blow onto the heatsinks providing adequate cooling.
After 10 hours of the lights being on, the heatsinks are barely warm to the touch! This is with 700mA - I might bump it up to 1000mA to get even more light.
james3370
Premium Member
silly question....if i decided to do (3) white LEDs for a fuge light wired in series, could i just splice them to a small wall wart or would i still need to run the buckpuck between??
i have a wall wart that is 12v/800ma that i thought about using. could it be used on (3) w/out the buckpuck??
i have a wall wart that is 12v/800ma that i thought about using. could it be used on (3) w/out the buckpuck??
der_wille_zur_macht
Team RC
Do you have a (cheap) source for the heatsinks you used?
Looking around online to find cheap sinks in about that dimension is like trying to get a sip of water from a firehose.
der_wille_zur_macht
Team RC
You'll need something to regulate the current. Otherwise, tiny fluctuations in the voltage put out by that wall wart will render your LEDs inoperable (i.e. either they'll be too dim to matter, or the smoke will get let out).
Also, keep in mind that the 800mA rating on the wall wart is not to indicate that it will regulate to that current, but rather that 800mA is the MAX - if you run at or over that, once again you'll let the smoke out. . .
I looked at the heatsinks on Newegg but it was tough to pick a good one as they didn't have any pics of the face of the heatsinks. So instead of shopping online, I went to my local Fry's Electronics to shop. It was good because I was able to open the boxes and actually look at the heatsinks. Many of the heatsinks weren't completely flat in the face and had beveled edges so the usable surface wasn't that big.
The heatsinks I went with were the ThermalTake TR2-M3 CPU heatsinks. They were $12.99 at my local Fry's, and I found two "open box" specials that were going for $12.34.
I looked at Newegg and looks like they've discontinued that item, but maybe you can find it elsewhere.Here are a couple more pics of the heatsink:
Below is a pic of a copper base that was on the face of the heatsink. I just removed it, giving me the whole face of the heatsink for mounting LEDs.
der_wille_zur_macht
Team RC
Thanks for the info, but man I must be a cheapskate - I'd like to pay $2.99 for a heatsink like that, not $12.99. :lol:
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