I got this idea; instead of using a microphone and preamp at the end of a twisted pair, I would build a microphone, preamp and modulate a red laser with the audio and pick up the audio about ten yards away with a light detector. Notice that it runs on two 2V photovoltaic cells in
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Big Clive tears down and reverse engineers a Philips ultra efficient light bulb. It’s 60 watts equivalent but draws only 4 watts. It has a color rendering index of only 80, and costs about ten Pounds UK or about $13 US. This uses 8 filament strings of LEDs and the filament string drops about 200
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The lifetime of incandescent and LED lights is extremely dependent on the temperature at which they run – for incandescents, GE says it’s the inverse of the 7th power of the voltage – the voltage increases and the lifetime decreases. In the case of LEDs the problem is most designs sacrifice thermal management to get
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Blinking LEDs are usually reset by the voltage dropping to zero then coming back on. So if one LED, probably the fastest one, blinks first, all the rest in the series string will be reset, then comeback on again when the fastest one comes back on. So you have essentially a single blinking LED and
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A string of LED xmas lights had been fritzing on and off, then it finally failed. I had to pull out 4 lights before I found two that were dead. I had to file off the ridge around the base to get them to fit properly into the base. So it’s back working again. It
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LED streetlights are decimating moths in England. The LEDs have blue light which insects use to see. The moths are pollinators like bees plus they’re food for many animals. There are a number of solutions for mitigating the problem. The blue light can be filtered out, among other things. My thinking is that the streetlights
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I found that 100 uH was a good all around value for these solar garden light circuits. But at the time I made these around 2009 the 5252 4 legged chip was uncommon and almost all the garden lights used 2 discrete transistors. I don’t know why they started using the 4 legged 5252 –
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From FB group electronics hobbyists Over the holidays I installed two solar 60 LED lights I bought on eBay. They stopped working just a few weeks after. I finally got up on the ladder and took them down to see why they died. Well, spit! The solar panel is plugged into the jack on the
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From FB comment to Bill Sherman’s candelabra lamps. Bill Sherman Sometimes I wonder what is meant by dimmable. If a LED light uses hundreds of microfarads for the DC filter capacitor, then when the light is dimmed, the long time constant causes it to flash on and off when it is dimmed. So if the
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I’ve had several LED purchases that were LEDs of poor quality, actually factory rejects. The sellers may not have known that the LEDs had “chipped chips” missing a piece, or bubbles or inclusions, but even more commonly, the LED chip is off center so the beam pattern is distorted. I let the sellers know, and
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