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    Li-ion small cell charger ICs

    When I open up an electronic product to see what's inside (and how well constructed) and sometimes to modify or repair, always interested in chips that are used and if I detailed data is available (like a good datasheet). I was noticing a lot of little 5- or 6-pin SOT Li-ion charger chips...
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    LiFePO4 dead cell recovery

    A couple of solar lights which use LiFePo4 14500 cells had been sitting around in the box for a while. When removed one read close to 0v, other about 1.6v. I have a proper charger for these cells (Rydelec) which seemed to not want to charge them; if at all, at extremely slow rate. Charger worked...
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    Control ICs in small LED devices

    I am wondering if anyone here has insight into the identity of small control ICs found in low-cost LED devices such as RGB LED strips, work lights etc. This would include vendors and specific part numbers/families. Commonly they are 8-pin SOICs with no markings, either made that way or markings...
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    18650 cell adapter tube

    I looked around for available cheap tubing to adapt diameter of 18650 to battery chamber of some flashlights designed for round 3AAA holder, but are long enough for the 18650. Ordinary 3/4" PVC water pipe OD was good but the walls are a bit to thick, ID too small. I found a piece of...
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    LET device?

    Has anyone heard of, or seen, an obscure device called Light Emitting Triac (LET)? I believe it was an early attempt to combine power control with lighting in single device; possibly GE? It may have been late 1980's to early 1990's. Dave
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    reclaiming alkaline (and other) cells

    For about the last dozen years I have been scavenging battery recycle depots at various places I have worked; and now have several years' supply of partially-used but still useful alkalines: AAA, AA C,D, 9v and some lantern batteries. They are being used in a host of small LED devices: lanterns...
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    Christmas lighting 2020

    Just thought to start a thread on lighting, including what's new out there. I notice a proliferation of more expensive, elaborate lighting including lighted figures (e.g. wire-frame reindeer, Santa etc.) and lighted trees, not really new; and projectors either of coloured dots/patterns...
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    12v/24vdc 9-LED spotlight open/troubleshoot

    Interesting experience with a 12v/24v 9-LED spotlight picked up at HD for 75% off ($7.50).Last one on the shelf, had been opened but decided to take it. https://www.homedepot.ca/product/briteled-utilityled-9/1001491688 Powering up using variable supply, 3 of 9 LEDs did not light, and the...
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    RGB LED colour mixing

    I came across this interesting (though very detailed) article on calculation of RGB mix ratio for LEDs to get "white", whatever it might amount to...
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    Small LED usage/projects

    I just thought to start a thread on small LED usage: leaded 3mm, 5mm, 10mm, DIP etc. or SMT, white or colour, special function (RGB, colour shifting). Could discuss uses, small projects, sources, specs/characteristics and other topics. I'll start off mentioning a small project of replacing...
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    Hallowe'en lighting effects

    This year due to COVID situation, in my area door-to-door will be curtailed, maybe not even happen. I guess for me it's down to "celebrating" Hallowe'en with lighting effects; stuff that's visible from the street. I stick to practical things which get re-used year after year until they...
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    VLC LED desk lamp, mode change

    VLC stands for Very Low Cost :) I have been using small cheap touch LED table lamps for a few years. They are convenient and work remarkably well for the price ($4 typically) as sources of low-level light for short intervals. These run from 3xAA, some also from 5v through USB jack. Some...
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    LED T8 fixture/tube compatibility

    The market for 4-ft T8 LED replacement tubes seems to be getting less predictable as far as compatibility with fluorescent tube fixtures, even those meant for LED tubes. I just bought a dual-tube 4-foot T8 LED shop-light for good price, $42 plus tax, including two tubes; this despite...
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    RGB LED bulbs, ac powered

    Who else has played around with low-cost RGB LED bulbs powered by ac? A local dollar store had them for $4 which includes small IR remote which works within a few feet. Bulb marked 3W, 200 lumen which seems reasonable though hard to compare efficacy with white bulbs. Package marked...
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    Specialty bulbs: switchable CCT and battery-backup

    Does anyone find these adjustable-tint white LED bulbs useful? I picked up one with Feit brand (model A800/CCT/LEDI) with 4-position slide switch to select 2700K, 4000K, or 5000K, or mode which changes by toggling light switch. I can't see a whole lot of cases where the tint really needs to be...
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    Repurposing (and PWM dimming of) 12v LED "auxiliary/offroad" lamps

    Not sure if this is exactly the right forum, as this is not for automotive use. I have acquired a variety of 12v LED "auxiliary/offroad" lamps with one aim to use with solar-charged battery for low-level lighting around the house, or outside. These lights are not meant for main automotive...
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    LED T8 tubes: any hazardous substances?

    I broke the glass shell of a LED T8 (or might have been broken in the store). Sharp glass aside, are there likely to be any hazardous materials in there? I imagine no mercury as it not a gas fluorescent, but noticed a bit of fine white powder which is not likely phosphor on the outer tube as the...
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    9v battery LED drive circuit

    Could someone recommend a simple, low-cost buck converter circuit to drive a single white (or other) LED at up to 20mA, from one 9v battery whose voltage could drop to less then 4v? I've looked at a number of LED drivers but most are boost for driving multiple LEDs in series, for display...
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    LED T8 tubes/fixtures

    I picked up a pair of LED T8 4-foot tubes, Honeywell branded, 18W. They advise using only with electronic "instant-start" ballast. I got a 2-tube fixture which matches the description. First test, one tube lights very dimly, almost looks like leakage current, the other not at all. Swapping...
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    trend in low-power coloured LEDs?

    I like to fool around with low-cost LED devices...flashlights, night-lights, small lanterns and battery-powered strings, etc. some of it being dollar-store grade, but what the heck. Over time I noticed more strings using multi-colour LEDs changing from pure colour LEDs, to all white LEDs...
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