Cree vs Bridgelux......what say you?

[Scutterborn]

Oh 3 for $450.... I thought each...


My bad...

Dang, Tony! Pay attention!!

[The_wolfeman]

Isn't the cost of each vega around $500? The fixtures I was looking at include 3 fixtures.

I guess in the end, you get what you pay for.

You definitely get what you pay for in this hobby. There are plenty of ways to save a few bucks here and there but I think crucial elements like lights are one thing that should be quality. You would need about three fixtures if you went with AI Vegas, they are rated for 2'x2' of coverage. I have 2 Vegas over a 3' 65g and I love them. Definitely worth the investment.

[alton]

I am bidding a job next week and I went to look at the specs of the pole lights

http://www.cree.com/~/media/Files/Cr...alight3mda.pdf

On page two it says the LEDS are projected to perform 50,000 hours at 59 degrees F or 15C. But in SOTX we know the fixtures will be in 80 to 90 degree F or 30C. Since Heat is a killer for LED do you divide the 50K by 2 since you are doubling the temperature?

[BBQHILLBILLY]

that is a projected calculation not an actual test calculation, your case temerature will be higher than 100 degrees, the other variable is everything around the LED
not sure on the question, not enough information, I dont make light poles, but if you exceed the test spec, you may have a dramatic loss in integrity
The casing is not vented, was this test done in New York, just my thoughts, where was the testing done

[BBQHILLBILLY]

i forget these lights come on at nighttime when it is cooler and at that height, wind shear will play an affect in cooling.
But if you place something on the car dashboard during the day in san antonio,
the material will change from the excessive heat

[BBQHILLBILLY]

someone help here lol

Thermal Loss

LEDs will decrease in relative flux output as junction temperature (Tj) rises. Most LED data sheets list typical luminous flux at Tj = 25°C, while most LED applications use higher junction temperatures. When using Tj > 25°C, the luminous flux must be derated from the value listed on the LED's data sheet.

LED data sheets include a chart showing the relative light output versus junction temperature such as the one shown in Chart 3 for XLamp XR-E white LEDs. By choosing either a specific relative light output or a specific junction temperature, this graph shows the value for the other characteristic.

For the CFL example, this luminaire is only designed for commercial buildings with vented ceilings. Based on the listed design goals, this design will prioritize light output, efficacy, and lifetime.

XLamp XR-E LEDs are rated to provide an average of 70 percent lumen maintenance after 50,000 hours provided the junction temperature is kept at 80°C or lower. Therefore, the appropriate maximum junction temperature for the CFL example is 80°C. This corresponds to a minimum relative luminous flux of 85 percent as shown in Chart 3. This 85 percent relative luminous flux is the thermal efficacy estimate for the example luminaire.

Chart 3: Example Relative Intensity versus Junction Temperature Graph for XLamp XR-E White LED source http://www.digikey.com/us/en/techzon...ign-Guide.html

[Big_Pun]

shane who cares if my leds crap out ill use warranty or just replace the module easy snap and plug in. another reason to buy from a reputable company.

[BBQHILLBILLY]

dont know what your talking bout Chris, I tried to figure out Altons question, related to his data sheet. I couldnt find his answer lol
May just be a electronics formula somewhere, my electronics is rusty ugh

[Big_Pun]

huh I dont know what your talking bout Chris, I tried to figure out Altons question, related to his data sheet. I couldnt find his answer lol
May just be a electronics formula somewhere, my electronics is rusty ugh

im saying i dont care how long they last at what temp as long as i can easily replace them, everything fails sooner or later

[BBQHILLBILLY]

yes i agree 100%