terahz
1x10^12 Hz
The Kessil gooseneck can be loaded down with about 737 grams (1.61 lbs) of weight before the arm gives.
Thanks.
The Kessil gooseneck can be loaded down with about 737 grams (1.61 lbs) of weight before the arm gives.
Nice and clean! Did you take any pictures while you attached the heatsink? DO you think one of these could support multiple chips?
Power LED´s shall be connected in series - its easier that way. If you use the driver I mentioned - yes you can take the 5 whites in series to one of the drivers and the 5 blues in the other chain.
The heatsink i got from Ebay (somewhere) The other construction (arround the heatsink) I found at my job, it is two covers from a cable duct. Use your imagination
Sincerely Lasse
Yes - five RB connected in series to drive 1, 5 white connected in series to drive 2.
Remember that you can not use a computer to dim this driver. You have to manually dim it with the potentiometer that comes with it. I have experience with a similar drive (100 watts), and there is no smooth dimming - but of course it is possible to dim it.
Sincerely Lasse
The bigger point is power output flexibility.
wow.. quick repond from you Mr.Lasse.. thanks so much..
you said in few page in back that 10W 20K is look like a more "yellow" than a 10W 16K.then with my combination,did you think that the light will be more white or more blue ?
thanks for helping a dummies like me![]()
Here is a google sketch of a standard 125 with LED's hung at 27" above tank base or 6" above water line.
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The larger cones are 90 degree optics and the smaller cones are 60 degree optics.
How concerned should I be about the light only having a 12 inch diameter at the water surface? Even smaller with the 60 degree optics.
The original comment was on the idea of $100(ish) saved on a DIY LED vs a Kessil LED... not LED vs MH.The cost savings also includes a lower electricity bill due to less power for the same amount of light. Also less heat requires less cooling, less evaporation and therefore less top off water.
The use of Lens do not drasticly chage the equasions for the distribution of light per distance. The formula still remains that if double the distance you will reduce the light by 1/4 th. What lenses do however is concentrate the light in a smaller area.
Sorry, this just isn't the case. If what you were saying was true, then using a reflector/lens on any light would gain you nothing. If you concentrate the same amount of light, ie number of photons per area per second, on a smaller area you have increased intensity, and this is precisely what reflector/lens do, albeit with some loss. One way to think of it is to consider the size of the circle of light that's projected. If you have a 60 degree lens and place it so you have a projected circle of say 18" diameter, say 18" distance, and then took a 30 degree lens and made the same size circle though from a greater distance, you will have the same intensity of light in that same area, less transmission losses (virtually zero through air) and any difference in lens/reflector efficiency. However, if you measured 6" closer to the lights from that 18" plane, the narrower beam will gain less intensity because the size of the circle will be larger than with a wider cone angle.
Basically, a tighter lens will net you less difference in PAR from one level in the tank to the next, but you will have to run the lights higher to achieve this. It won't gain you more PAR over a wider angle lens at a given spread, but can make for much more even lighting.
With a sufficiently tight beam, there would be no difference between the intensity at the emitter and at the destination. An excellent example of this effect is coherent light (IE LASER beams). There is (ideally) no cone angle to the beam, and so the only losses are in transmission, something blocking or absorbing the beam.
The air-water interface is where things get tricky, if there was a perfectly flat surface with no reflection, the water would bend light rays towards the surface normal, in effect causing a lensing effect and reset the whole distance equation with intensity. However taking into account reflections, and the fact the water is a bit turbulent you get all sorts of brain numbing effects to take into account, so to the best of our ability we'll simply say 1/r² type behavior![]()
I placed an order with eBay sell ac-rc. I'm in the US. About how long did it take for everyone else to get their orders? Thanks.
For me, about ~14 days if you live in SoCal. Longer if anywhere else. As soon as it hits the U.S. and gets through customs USPS takes over.