I drew this schematic up a few years ago (2009, IIRC) when I first made the Supercharged Joule Thief. It was supposed to help me keep track of the several SJTs that I built, and continued to build to validate the design. I suppose I should delete all of the text in the schematic, and
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Wanna Make A Garage Door Open Alarm This is a continuation of my previous blog. I could use two 555 timer chips in the astable mode to generate a European type siren with the high-low ‘warble’ tones, but I decided I would do it with a couple transistors. Actually I coul+d use a single 556
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This is from the 1980s, it’s all red LED segments or dots. I tried to find an angle where the ceiling light would not show, but because it’s a bubble lens, just about any angle had that white reflection. The specifications are available on the ‘net. The box outlined in red is one of the
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I wrote a short blog about the Cree LED lights recently. Last week I bought two Cree 450 Lm (40W equivalent) LED lights from Home Depot for ten bucks apiece. The UPC label number is 13959 01932. I installed one of them in a task light I have over my laptop, which gets heavy usage,
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I did learn something from the Grease Spot Photometer Experiment. I found that the grease spot really does work. I can compare the brightness of two LEDs to find out the current in each LED. But then I realized that I don’t really need two LEDs (I didn’t use two with my luxmeter measurements). All
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I thought about doing this since I wrote a blog on it back in the mid 2000s. Use the Grease Spot Photometer Method to compare the outputs of LEDs. This experiment is used in Physics classes to demonstrate the relationship between candles and the distance to the light source. In my case I decided that
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I’m trying to figure out how these Miracle LED people get away with advertising a two watt LED light is equal to a 60 watt light. These are supposed to screw into the sockets of a ceiling fan, and come in a set of four for fifty bucks when tax is included. Also, they say
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I bought an EcoSmart 40 watt equivalent LED light bulb from Home Depot on sale for under $12, regularly $20. It is very similar to this one (I couldn’t find it on Home Depot’s website). It was a bright white, which seems to be the only color they have on the shelves. Apparently all of
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Paul emailed and said he has built his 12th Joule Thief. Man, this guy is Helen Wheels – an even dozen in a matter of a fortnight (or week or two, I forget which). I’ve been puttering with the TE Flashers. I made most of them on small pieces of “Woodsie” wood that I got
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I found this LED website in Germany, I like it because it’s LEDs, LEDs, and more LEDs, and not an electronics parts distributor. The LEDs are broken down into various types, standard, high power, etc., etc., etc. I’m looking for a similar website of a store in the U.S. I figure it would be best
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