Recent content by Dave_H

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    6V "Lantern" Battery Lights - History? Anything good?

    None of the few 6v lanterns I have (had) are that great, nor do the brands matter. One was a showerhead. Another was a bulb retrofit with Dorcy 3-4 cell (sub-1W) bayonet base which were popular a decade ago; not overly bright and the beam pattern and CCT changed. I've been running down...
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    What is the next big thig in LED technology?

    Having done some modest experimenting with fluorescent fixtures and "retrofit" T8 4-ft. LED tubes I concur it is hit-and-miss. First case, instant-start electronic ballast, none of several brands of LED tubes worked, including Philips; but neither fixture nor tubes were defective, everything...
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    Are computer screen backlights upgradeable?

    Earlier discussion on related topic in this thread: Dave
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    Looking for 12 volt LED lighting from a car battery - illumination for a shipping container cabin

    Agreed, most 12v auto auxiliary lights I have or have seen are 5000K, some as high as 6500K. Nevertheless some of these may work for certain situations, and I am seeing some really good specials on some (if money matters); locally OTC 4" 9-LED 10W light 4-pack for $20; smaller 5-LED 4-pack for...
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    Cheap ebay solar LED lights with li-ion 18650 batteries.

    One may get away with using LiFePO4 in a circuit charging them to 4.2v, but expect lower life; how much lower I could not say. I have a solar LED rope light with 90 (!) green LEDs, which has operated for a couple of years every day, from the same 14500 cell. Without looking inside (though I...
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    Best Automotive DMM's (non-RMS)

    Good that you mentioned AC as all the "automotive" DMMs I've seen however rugged and reliable do not have any AC voltage ranges below 200v FS. Obviously not good for testing low-level audio in you system if it comes to that. Basic DC accuracy in modest hand-held lab-type DMMs is better than...
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    Cheap ebay solar LED lights with li-ion 18650 batteries.

    I definitely recommend against putting LiFePO4 cell into any solar device (or anything which charges) meant for regular Li-ion. The former will be overcharged and ultimately damaged. I am not sure what are safety risks, but in any case the outcome will not be good. You can certainly run...
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    What‘s your favorite headlamp?

    As I typically use mine around the house outside for short periods, collection here is of cheap ones mostly of obscure brands, no sexy names or high prices. They all pretty much run from 3xAAA, alkaline or NiMH. They are useful for close-in lighting inside where both hands are occupied, and...
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    Power Supply Output Voltage Error

    I believe that the 30-57v dc output applies to under load, but not sure what is normal upper limit under no load; probably should not go up to 74v though so might be defective. I could try it on a couple I have around but may not be definitive answer. What are specs for the LED strip, is it...
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    Need something that uses this battery

    Some cheap but otherwise good LED flashlights which are designed for 3xAAA using round cell holder (which has contacts at both ends) can take 18650, possibly without the +ve bump. Many do not state this in their spec. You probably have to physically check specific light unless it's known to take...
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    Help -- Trying to run LED strip light on a battery

    In absence of a spec or your measuring it, can't be sure but you might be able to use a 12v 1.5A wallplug adapter if you have one. They are cheap. It's very helpful to obtain a digital multi-meter (DMM) which measures voltage and current (you can calculate power from this), and resistance...
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    Looking for 12 volt LED lighting from a car battery - illumination for a shipping container cabin

    It's sometimes referred to as "auxiliary" lighting generally meant for off-road/farm/ utility etc. vehicle use being generally not suitable (read: safe/legal) for main vehicle lighting; but perfectly good for other 12v/24vdc uses including fixed. Much of these are spotlights or barlights...
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    Help -- Trying to run LED strip light on a battery

    What is the LED strip: type of LEDs and number per foot/metre? How much current (or power) does each strip draw from 12v for given length; is it specified or can you measure it? As mentioned the tiny 23A is 12v but completely inadequate for high-current loads. It's mainly used in remote...
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    Question about solar chargers

    Second-hand stores often end up with slower chargers which are perfectly good but ditched as they are too slow for some users; but perfectly good for small solar charging setup. They are usually only a few dollars each. I keep an eye out for those which charge cells individually versus in...
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    Show your nightstand flashlight!

    I have a similar clip-on 9v single LED mini-flashlight on the night table. This one points up against a round wax "candle" (also a flickering LED device) which diffuses the light. These are great for running down used 9v batteries which come out of smoke detectors, DMMs etc. but still lots left...