LED lighting

[bdejong]

Stewie is one of my many cartoon hero's, along with Hank from King of the hill.

[Jotabe]

Hello Brian,

Thank you for the X-Lamp overview/update ... if I get my act together ... I may send you a schematic for review. I 've got a prototype line ... pick and place ... 5 zones ... if it get's to the point PCB's are made ... no issues with running boards through. I think the key is to come up with a modular design where the boards can be hooked up in series.

On the Power Supply Side ... I go back and forth from off the shelf to DIY. My DIY thought is .. setup a 48 VDC bus ... average Vf ~ 3.7 Volts at 1 Amp ... 12 LED's per string .. regulate the current through a Power BJT ... PWM to change intensity.

Now if Safety isn't an issue .. Voltage double the AC ... and then you are > 50 LED's a string ...

If you were to use XRF's to mimic a 250W MH 20k bulb and a 250W MH 10k bulb ... what's your best guess at the number of LED's required ... given a 700 mA drive current?

Appreciate the help ... and sorry if I am being too direct with the questions ... I am just glad to be talking to some one from Cree. I just to be clear ... I am looking at this from a pure hobby position.

Best regards,

J.B.

[Jotabe]

Here's a very first order calc ... AquaIluminations claims 1/3 savings on a MH 250W bulb ... (assume no ballast loss) ... ~ 167 Watts for the LED Power ... 0.7 Amps at 3.5 Vf .. 2.45 Watts .... ~ 68 LED's

So cost per 250W equiv is 68 LED's x ASP ... if ASP is the Disti costs I see on the Web ... I can why the fixtures are selling for ~ $3k

I think AquaIluminations/Solaris uses Lumiled's so if Cree delivers more "light density" per Watt .. then the LED numbers go down.

A late night calc. .. please don't flame me on it if I made some errors.

Regards,

J.B.

[21twan]

Any updates on this?

[fatman]

Originally Posted by bdejong

Let remember that PAR is not a measurement of light, PAR as I know it is an acronym for Parabolic Aluminum Reflector.

PAR in the aquarium trade is a measurement in watts/m^2 of the specific light wave lengths used by coral striking a specific target. It differs from LUX which is a measurement of light as seen by the human eye. The aquarium PAR does not relate directly to solar incidence as using in thermal gain calculations for thermal heat provided by the sun in different geographical areas, even though the units are the same, as the wave lengths of light producing the different readings are quite different. For specific information on light wave lenghts for a reef aquariumsearc "Dana Riddle Halide Lighting Tests," this should provide several URL's at different Reef forum sites, where he regularly contributes. Joshi is another contributor to Reef sites of a more technological bent.

[prowl]

Are there any updates on this topic?
we are trying to build a system that resembles yours but now we have some trouble with the assembling of the light(color)spectrum. Does the person who started the topic ore maybe somebody else have some examples, tips ore suggestions on this subject. All links or articles on this type of subject are welcome!
Our goal is making light that produces less heat and has a higher lm/watt. But most important is a better lightspectrum for the corals so that they can grow better and faster under the same amount of energy.

[fatman]

I wish now I had a quantum meter to loan you, but a Lux meter is all the further I have advanced in that area of reef monitoring. I just assume my PAR decreases proportionally to my Lux and use the Lux data to place my corals and replace my halide bulbs.

[prowl]

Originally Posted by fatman

I wish now I had a quantum meter to loan you, but a Lux meter is all the further I have advanced in that area of reef monitoring. I just assume my PAR decreases proportionally to my Lux and use the Lux data to place my corals and replace my halide bulbs.

I wish those instruments where not that expensive but they are
@fatman: where are you experimenting with? Can you give a more detailed explanation?