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Author Archives: gregorykimball
USB car charger, 2A
The more I’ve learned about switch-mode power supplies, the more amazing it seems to me. So a voltage source across a wide range of values can be converted into another voltage, just by pulsing current though an inductor. Of course, switch-mode power supplies are even easier to set up with ICs like this one:
IC REG BUCK BOOST, 296-17764-5-ND
Posted in Electronics
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Cree XM-L Color
This one is truly a beauty. Here is the new RGBW high-power LED from Cree.
XLAMP XM-L COLOR LED RGBW (XMLCTW-A0-0000-00C3ABB02CT-ND)
Posted in Electronics
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Flea market wafer
I even got to play the rube and ended up paying $20 for a 8″ silicon IC wafer. I think this one was the most beautiful one the vendor had in stock:
Posted in Electronics
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Photon Battery Device (PBD)
Hey it worked! Finally put together my new solar-powered ultra-high power LED and it’s sweet! The solar cell is 1W and the LED runs at 2W, so for every two minutes of sun you get one minute of light!
Posted in Electronics, Solar
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LED First Light
Wow, LED’s are amazing! I just fired up my Cree XM-L2 LED with a 3-cell NiMH battery pack and a 0.91 ohm resistor to keep the current under control. The circuit runs at 500 mA, which corresponds to 1.4 W for the LED and 0.4 W for the resistor… or 75% circuit efficiency and probably just shy of 200 lumens. With 2000mAh batteries I should get about 4 hours of light.
Posted in Electronics
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Carpentry!
So I finally got around to making a proper spice rack for the kitchen. The old one was overflowing and spices were falling everywhere, but luckily there is a home depot a few miles nearby. You almost can’t see it in the picture, but there is an acrylic sheet keeping the spices from falling out, while also leaving the spice labels fully legible.
Posted in Home projects
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Bike!
This is my ’85 Schwinn Sprint, an entry-level road bike. It was made on November 7th, 1985 in Taiwan by Giant Bicycles. The gearing is classic 10-speed with 40/52 crankset and 14/17/20/24/28 freewheel.
Posted in Bikes
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Best Fossils Ever…
So I started getting a hankering for some fossil fuels. The good stuff: light, sweet crude oil and anthracite coal. These are the finest fossils that the earth has to offer us, refined and smelted over millions of years. They burn clean and pure with a clear flame and a light wisp of carbon dioxide.
Posted in Uncategorized
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Gregory Kimball 
