LED and LED Supply Group Buy!!!!

Discussion in 'Group Buys' started by heyitsomid, Sep 16, 2009.

  1. yardartist

    yardartist Guest

    Got it Dudley.

    Anyone else looking for LED lamps or a ELN-60-48P Meanwell driver?
     
  2. heyitsomid

    heyitsomid Guest

    Here are the totals:
    104whites and 127 blues = 219 total which puts us in the $5.60 range.
    tonggao:
    2 white, 9 blue = $61.60
    Gomer:
    20w,20b = $224.00
    Roberto:
    12w, 12b = $134.40
    me:
    18w,18b + 4 XPG R4 = $231.60
    Andrew
    30w, 30b = $336.00
    yardartist:
    16w, 32b = $268.80
    Dswong01:
    6w, 6b = $67.20
    Total price = $1323.60
    I pm'd a few people and they might join in as well. Price may vary depending on shipping cost and tax, which haven't been calculated into prices. The order will be sent ideally on Thursday.
     
  3. JAR

    JAR Supporting Member

    I got the PM
    After reading this about soldering, I am going to wait.
    http://www.cree.com/products/pdf/XLampSolderingandHandling.pdf
     
  4. Gomer

    Gomer Honorary Member

    I would agree with the aprehension if these were raw emitters, but..
    so, they will be easy to handle :)
     
  5. euod

    euod Supporting Member

    20w + 20b
     
  6. yardartist

    yardartist Guest

    Thanks Omid!
     
  7. heyitsomid

    heyitsomid Guest

    newest update
    Here are the totals:
    124whites and 147 blues = 259 total which puts us in the $5.60 range.
    tonggao:
    2 white, 9 blue = $61.60
    Gomer:
    20w,20b = $224.00
    Roberto:
    12w, 12b = $134.40
    me:
    18w,18b + 4 XPG R4 = $231.60
    Andrew
    30w, 30b = $336.00
    yardartist:
    16w, 32b = $268.80
    Dswong01:
    6w, 6b = $67.20
    euod:
    20w, 20b = $224
    Total price = $1480.40
     
  8. tonggao

    tonggao Guest

    Depending how deep you like the light to reach, you might also be interested in optics (come in 40, 60, 80 degrees, and maybe more). If I remember it right, ETG also sells the Cree optics for XR-E, for about $1 each, which is not a bad price. JFYI.
     
  9. Gomer

    Gomer Honorary Member

    For ~ $1 each, I'd also be interested in 40 60deg optics.
     
  10. heyitsomid

    heyitsomid Guest

    Any last takers? I'll put you down for optics Tony. Tonggao if you'd like optics let me know ASAP!
     
  11. tonggao

    tonggao Guest

    Thanks I do not need any optics, just passing info to the people who might want them.
     
  12. Gomer

    Gomer Honorary Member

    Optics also let you have a light higher off the surface. One thing I WILL eventually do (I've been thinking of doing it for years and years) is do use 8-10deg optics on a light for an open top tank, and have the fixture either embeded or up to the ceiling. It would work perfect for a smaller tank (24" cube or smaller) and would have the most amazing shimmer etc from the nearly orthogonal light rays to the surface. Being smart about it, you can have VERY little spill light which would create a huge viewing contrast.
     
  13. heyitsomid

    heyitsomid Guest

    Now that the LED order is in and being processed, we should switch gears and organize the heat sink order. Lets get on this faster than the LEDs because I know I like many of you would like to have your heat sink before the LEDs arrive :) I've done some research and found that the best place to buy them is heatsinkusa.com. They have recently upgraded their site and it is a lot more user friendly but if you still have questions on what kind of heat sink you want to buy PM me or ask the group.
    ~Omid
     
  14. yardartist

    yardartist Guest

    Omid, has anyone connected with you about heat sink? I have what I need.
     
  15. heyitsomid

    heyitsomid Guest

  16. Gomer

    Gomer Honorary Member

    I'm a retard. I was thinking the drivers were the D models (apply a straight 0-10V). The drivers are P models (again, my fault on not checking) which has the intensity controlled by a pulse modulation.

    Does anyone know if these are easily modded into D mode or if not, know of a good variable PWM schematic?
     
  17. yardartist

    yardartist Guest

    How about in English Tony?
     
  18. Gomer

    Gomer Honorary Member

    the drivers output is controlled differently depending on the D or P models (we got P)

    D models: current output of the driver (and thus intenisity) is controlled by supplying 0-10Volts DC to the driver. 0V is off and 10V is max (1.3amps*).

    P models: current out put of the driver is controlled by "pulsing" 10V to the driver. The longer the on time of the pulse is the more visual intensity. If you pulse at 100% duity cycle, the driver outputs constant 1.3A*. If you pulse at 50% duty cycle, the light outputs half the time averaged intensity. It looks constantly on, but is really flashing on-off-on-off etc where on is 1.3A and off is 0A.

    There are some simple 555 IC designs (I can explain later) that we can use to make a cheap PWM "driver" for the drivers using radioshack items. You would want to use the pot inside* to set the P models to 1 amp or you will likely burn up LEDs.

    *I've read a little and there is a pot inside that we can turn to set the driver at -25% output or 1.3A * 0.75 = 0.975A. This means 10V on D is ~1A and 100% on P is ~1A
     
  19. JAR

    JAR Supporting Member

    This might be a good option for the MEANtime!
    Thanks for checking!
     
  20. sfsuphysics

    sfsuphysics Supporting Member

    So is there any advantage to pulsing? I'm guessing that's how it deals with adjusting voltage for a variable brightness? What sort of frequency is the pulse at? I'm guessing fast enough we don't notice.

    To me seems kind of strange that the pulsing would be what changes the brightness unless there's some sort of hysteresis with the LEDs, because other wise if you pulse at 1 hz or 1Mhz you'll still have the LED off for the same amount of time as on over any given time period.
     

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