Recent content by LEDphile

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    Battery life for low power draw devices

    Energizer provides discharge curves for both their alkaline and lithium batteries at An L91 (Lithium AA) is good for ~3500mAh at discharge rates under 100mA, with a reasonably consistent output voltage over lifetime. The E91 (Alkaline AA) is good for perhaps 2700mAh...
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    DIY Hunting LED Spotlight - design suggestions

    Comparison was to the 70W HID, on the assumption that if the OP was looking for more output, they'd go for the more powerful upgrade. So 3x XP-L HI to match the 50W seems about right
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    Looking for something specific.

    Pelican 2460 and 5050R are both close but miss on a few points.
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    noteworthy timeline of lights

    There's a few things at play with rated lifetime decreasing. The first is that, indeed, LEDs cost money so using fewer and driving them harder results in a lower cost product. But the other big factor at play here is that the early lifetime numbers were based on some pretty wild extrapolations...
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    Replacement bulb for microscope lamp

    Running an 8V lamp at 6V results in a lower output from the lamp, but a rather longer lifetime. At 6V, that lamp was likely drawing about 9W. A #81 lamp is a clear bulb and slightly lower output than stock, but is pretty close and is plenty cheap enough to try as an experiment, especially if...
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    Disaster Light for Emergency workers

    Instead of asking your team to use different gear in a disaster situation than what they use day-to-day, why not have the "extended operations" kit be spares for the primary lights your team already uses? If your existing lights can take AA NiMH cells and you have access to power, the spares...
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    best throw head for malkoff md3

    Double the candela results in an increase of the throw distance (distance to a specific light level) of about 40% due to the inverse-square law. So not a massive increase, but not zero, either.
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    Flashlight Grip Tape

    Check your local sporting goods store for hockey stick tape
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    Novatac 120T serial 12269 pics and questions

    Got a link to those old posts? I'm happy to be educated, but I didn't find any posts on this topic with a couple searches and looking through about 20 pages of search results. And it seems like you were being sarcastic, but it is possible to correlate measurements made with a light meter in an...
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    Novatac 120T serial 12269 pics and questions

    Using a light meter (lux or footcandles) to measure lumens is challenging because you need enough measurements to be able to take the beam distribution into account. But assuming that you can take the required number of measurements (e.g. by using a goniophotometer), color and tint have almost...
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    Chip shortage causing car shortage. Same with flashlights?

    Current part lead times are over a year for many components, including some LEDs. How much of a concern this is depends on the ability of the end-user manufacturers to manage their supply chains and source parts through distributors that may have stock. Some of the problems are due to the...
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    Spotlight for firemen

    XQ-E HD or XQ-E HI? The HI is the flat-top version, and what you need for the narrow beams. The flat-top packages from Cree are XP-P and XQ-E HI (1mm2 die), XD16 (2mm2 die), and XP-L HI (4mm2 die).
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    Spotlight for firemen

    As you've already found, shrinking the source size will allow you to shrink the optic size for the same beam angle. The flat-top LED packages provide higher candela than the domed packages, at the expense of lower total lumens, and are where I'd be looking as far as LED choice.
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    Light cutting out due to corrosion

    I'd try a bit of dielectric grease (readily available at most auto parts stores) on the threads
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    Retirement trips planned-Need a new light

    I think the version you're looking for is at least assuming you need everything but the batteries