I came across this .PDF a while back and I had one thing I wanted to show about it. The circuit is okay, but the 2 ohm current sensing resistor in series with the LED wastes about 25 percent of the power of the 1W LED. There is a simple way to reduce this, and
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I touched upon this subject in my late, great watsoneblog, but not since then, I believe. What I came up with back then was simple and effective. I wanted to change the abrupt turn on and turn off of the LED into the much slower turn on and turn off of an incandescent light bulb.
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I went to my computer club meeting this Sunday and they had a really good deal on the consignment table that I just couldn’t pass up: three 21 LED panels for five bucks apiece. They’re built very sturdy, with a body of extruded aluminum and screws holding the end covers in place. The ‘handles’ on
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This is a continuation of the original June 14 blog. I don’t think I mentioned this earlier, but the 44 LED light circuit is so simple that there is no regulation, so the LEDs can be dimmed by reducing the AC voltage. I used a sine wave variable AC voltage. But most conventional dimmers use
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I found some LED lights on eBay for under 6 dollars U.S. with free shipping. They’re shipped from Hong Kong, so it will take a few weeks to get here. They said sometime around the 4th of July. Wow! Instead of lighting up firecrackers, I’ll be lighting up LEDs!! They call these corn cob lights
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I took this photo Oct 2003 and posted it to my watsonseblog. The ‘cup holder’ is the sliding drawer that comes out of the CD drive. Other motors inside can generate enough power to light up the LED.
I’m not sure why I haven’t dome this before. Actually, I have, but just not with a remote control. Perhaps it’s because I wouldn’t want to damage the remote control. But this time I bought some cheap GE remotes on Amazon for six bucks apiece, so the loss if I damaged one would be minimal.
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This is an old schematic that I drew in Apr of 2005 using SwitcherCAD III (now LTspice). It is taken from the board I built and put in service for several years as a LED test jig for testing the lifetimes of various white LEDs. Needless to say, most of the white LEDs lasted less
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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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