ReefEnabler
Premium Member
Honestly the optics are cheap enough that for your tank I would buy enough 60 degree optics and 80s to cover the whole setup with either, then try swapping them out.
DIY LEDs - The write-up
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The Grim Reefer
Ready for some NOBALL!!!
will that particular controller run 12 LED's? Seems to me that would be a little underpowered.
ReefEnabler
Premium Member
Question for anybody who knows about thermocouples...
Way back Stu was talking of touching the stars with a thermocouple next to the emitter to get a close ambient temperature reading. I think kcress said not to trust it since the thermocouple could act as a heatsink when reading something so tiny.
Well I can't get a reading with my IR thermometer at all, the area it reads from it simply too big and it gives me a way too low number.
So how in the heck do I get a good temperature measurement of a tiny point close to the emitter? Are there special thermocouples meant for that? I almost bought one on ebay but when I saw the thermocouple was a huge long metal rod I had second thoughts...
Way back Stu was talking of touching the stars with a thermocouple next to the emitter to get a close ambient temperature reading. I think kcress said not to trust it since the thermocouple could act as a heatsink when reading something so tiny.
Well I can't get a reading with my IR thermometer at all, the area it reads from it simply too big and it gives me a way too low number.
So how in the heck do I get a good temperature measurement of a tiny point close to the emitter? Are there special thermocouples meant for that? I almost bought one on ebay but when I saw the thermocouple was a huge long metal rod I had second thoughts...
der_wille_zur_macht
Team RC
The LPC35-700 is a fixed 700mA output and a 48v max. So it'll happily run 12 typical HP LEDs at 700mA. It's not dimmable or adjustable though, which is really too bad.
Many people are used to the ELN60-48 driving 12 LEDs, "turned down" from it's 1.3A max by a significant margin, which means it's being under-utilized.
ReefEnabler
Premium Member
I thought cooking thermometers work by sticking them INTO a substance, meaning you need good surface area contact for the probe to reach the temperature of your medium? Not sure how that would measure just based on a tiny touch of the tip. Unless we are thinking of different devices.
kcress
New member
You cannot use typical non-contact temp guns on shiny metallic surfaces. It's called emissivity errors. It's sort of like seeing the temperature of things reflected off the metal instead of the temperature of the metal.
You need to use a very small contact sensor pressed against the actual LED lead or directly adjacent to the large thermal pad connection touching the LED.
You need to use a very small contact sensor pressed against the actual LED lead or directly adjacent to the large thermal pad connection touching the LED.
ReefEnabler
Premium Member
What would such a sensor be called and what device would read from it??
The only things my googling has turned up are IR thermometer and thermocouples.
The only things my googling has turned up are IR thermometer and thermocouples.
stugray
Premium Member
You can get a Craftsman DMM that reads thermocouples AND does all these voltage & current measurement things I do to my LEDs.
Front panel says: 82139 ~$30 from Sears.
I used omega "fine" wire thermocouple wire in some of my testing.
As Kcress pointed out, the TC itself can throw off the measurement if you are not careful.
The BEST way to test these thing would be to use the smallest TC wire & run it under the Star, but you would need to cut reliefs in the bottom to accomodate the wire.
Stu
Front panel says: 82139 ~$30 from Sears.
I used omega "fine" wire thermocouple wire in some of my testing.
As Kcress pointed out, the TC itself can throw off the measurement if you are not careful.
The BEST way to test these thing would be to use the smallest TC wire & run it under the Star, but you would need to cut reliefs in the bottom to accomodate the wire.
Stu
L98-Z
New member
I started back working on mine last night. I opened up the ELN60-48. Where is the "knob" to turn down the current? I only see one that thing looks remotely adjustable, but I'd like to be sure before I start altering things.
Is there a picture or description somewhere. I'd like to wire up a 12 LED test panel tonight.
Skeptic_07
New member
I used a very small probe (about 0.5 mm in diameter). I inserted it into a hole I drilled to the back of the star. Filled the hole with Arctic Silver, attached the star and inserted the thermocouple.
You just need to use the smallest mass probe possible to minimize disturbing the system in either a negative of positive way.
Bob
L98-Z
New member
Ahhh, I had the datasheet in front of me and didn't even look at it. Oops.
der_wille_zur_macht
Team RC
My approach is complete coverage in as THIN a layer as you can get. this ensures the thermal paste is just doing it's job (filling microscopic surface impurities) and not creating a gap between the two parts. For the most part, if you're screwing down hard enough, the excess will squeeze out anyways.
Skeptic_07
New member
just enough to make contact is good. too much of it is bad. I usually use just a roughly 3/8" dab for a CPU so probably just a drop is good for one of these LEDs. it will spread out 
Use an amount that is like half the size of the head of a paper match. If you see any squeezing out as you tighten the screws down you used more than you needed.cyrusthevirus
New member
Dealextreme
Dealextreme
So I purchased my LEDs from Dealextreme.com for my build and now I am have a hard time contacting them. My order is listed as cancelled and I have been trying to reach them for over a week. Anyone have any contact information for them?
Dealextreme
So I purchased my LEDs from Dealextreme.com for my build and now I am have a hard time contacting them. My order is listed as cancelled and I have been trying to reach them for over a week. Anyone have any contact information for them?
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