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  1. J

    Need som help, modify Greenforce tristar

    Hi, I have upgraded several of these heads, but there are many different variations of this head. Posting a picture of the head might help. If you search with my username you can probably find some examples of what I've done with them. It's been a while since I did an upgrade, so I'm not up to...
  2. J

    Experiment: can an aspherical lense be substituted with a Fresnel lense?

    I used a Cree XML or XPG at that time. Given the 8-9cm at 2m I'm guessing it was the XPG. The blue/yellow distribution of LEDs is caused by how the phosphor is applied and not the issue I was describing. This color change is usually a problem when using extreme refraction angles. In my case you...
  3. J

    high power LEDs in 45° ambient temperature

    Hi, not sure if this is the right place, if not, please move or point me to the right place. my wife's family lives in Africa where day temperatures rise up to 45°C and night temperatures can stay above 35°C. in the near future, I'll be visiting them and 1 thing I would like to offer them is...
  4. J

    Ikelite Gamma

    I did something similar with 3 greenforce diamond lights. They originaly ran on cr123 liion batteries (non-rechargeable). I replaced the driver by an other driver designed for a single 18650 cell like an AMC7135 based driver and replaced the batteries by a 1 unprotected 17650 or something from...
  5. J

    looking for PWM controlled constant current component

    Seems like an interesting article. I'll read this more in detail. Perhaps I can generate a voltage from a PWM signal and use this as a feedback voltage. Since these feedback voltages are typically low, they may be very sensitive to any ripple that is left in the RC circuit. Thanks for the...
  6. J

    looking for PWM controlled constant current component

    Thanks for the trying to help and you seem to understand that I don't want the output to be pulsed. The reason I'm looking for this, is not for a flashlight or so but more for an industrial application where the pulsing of the LED interferes with a high speed camera. I know that if you pulse...
  7. J

    looking for PWM controlled constant current component

    could you explain this a little bit? I know mosfets are used as linear drivers, but I don't see how I can control the current with PWM? Johan
  8. J

    looking for PWM controlled constant current component

    don't worry about sourcing. mouser, digikey, RS compentens, Farnell etc are available to me. The problem is that when I search on PMW led drivers, I'm getting drivers that have a PWM output, which is not what I want. All drivers that I see use a resistor to set the current and dim the LED by...
  9. J

    looking for PWM controlled constant current component

    Hi, difficult to put a clear title, but this is what I'm looking for: A driver chip for high power LEDs that is constant current, and where the output current can be controlled using a PWM signal while the output is not a PWM output. So, I'd like to use a PWM signal to control the output...
  10. J

    6000 lumen video light set up

    ah, ok, that explains it, thanks. Johan
  11. J

    6000 lumen video light set up

    Wouldn't the voltage be too high when charged? I once had a setup with 3 XPG leds of which 2 in series with the driver and one connected to the driver. after a few seconds, the AMC chips went in thermal protection and started flickering on and off. The reason was that the battery was 14.4V when...
  12. J

    6000 lumen video light set up

    Hi packhorse, What outer diameter are those PMMA tubes? what kind of battery pack is used with this configuration? 3S liion? 12V NiMh? Johan
  13. J

    Video UW Light

    Can you show a picture from the front? What Ah do you have on the battery and how long does it last with this light? Johan
  14. J

    Modifying dive light for video/photography with lens.

    They claim that the bare LED has an opening angle of about 160°. if you look at the datasheet of an XML2, you can see that this would include almost the complete angle in which the LED is emitting. It is true that most of the cameras don't have such a wide view, but on the other hand, the amount...
  15. J

    Beginner needs help with parts matching.

    Hi, 10W HID lights can be easily replaced by LEDs. There are a few examples on the forum I think. Mostly they are replaced by a single LED due to the diameter of the head. I've a few such upgrades on greenforce 10W HID lights: - MCE + TIR optic from DX - MTG2 + deep reflector (very nice...
  16. J

    Need some help from you please

    9° for a 7x XML, I doupt this exists for the common 7x xml boards. if you're willing to use individual stars, it may be feasible. by the way, are you looking for 9° full angle (at 50% of the intensity = FWHM) or half angle? getting leds and optics at a good price depends entirely on where...
  17. J

    Tiny aluminium host for laser pointer?

    No I don't have experience with them so don't know if the switch will work. The second doesn't have a clicky switch, so it should be doable to convert it to laser I think. If you take the led and reflector out, and take a small laser, it may fit. not sure which laser you had in mind. There are...
  18. J

    Tiny aluminium host for laser pointer?

    perhaps dx.com sku's: 330307 199348 240699 (plastic)
  19. J

    New Halcyon steampunk torch

    I haven't seen any beamshots yet, but the fresnel lens will certainly project a square if the led they use is square. If the light has a corona, then they have the walls between the lens and led reflecting light as well, either with an actual reflector or just a reflective material/paint...
  20. J

    adjustable "focus"(spot/flood) mechanism

    How do you get to this number? A fresnel lens is not really different compared to a glass lens so a fresnel lens doesn't need to be bigger than a glass lens. I agree with packhorse regarding your 4° beam angle. With lenses, you should calculate the magfication to get an idea of the size of the...
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