Pulse Width Modulation is a topic that tends to give a lot of beginners trouble. [Daqq], whose nixie plasma ball we covered a few days ago, has a simple but effective PWM project that you should take a look at. The circuit used 9 LEDs clustered together into 3 sets of RGB modules and connected them to an AVR ATtiny2313 through some current limiting resistors. Most of the time the PWM function of the AVR’s timers would be used to generate the signal but this application calls for 9 signals which is more than can be produced by this…
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Software pulse width modulation
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DIY Lincoln welder conversion
[Fritz] built this 600 joule capacitive discharge spot welder in a case scavenged from a Lincoln plasma cutter. All of the circuitry was designed by [Fritz] and the schematics are available on his website. He has a few other welding related project also documented on his site that are worth checking out. While this isn’t the first homemade spot welder we have seen, it is definitely the first one with a case mod. If you are not up to the challenge of building one quite as complex as [Fritz]’s example, a microwave can be used as the donor appliance in simpler designs.
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Nixie Plasma ball
This one came out over a year ago and we missed it. [Daqq] has made a plasma ball out of a nixie tube. All that was required was the transformer from a cold cathode meant for computers and a nixie tube. He did have to do a tiny bit of modification to the power supply, which you can see on the project page. This isn’t the most useful project, since you can’t really see much of the plasma, but it is really cool nonetheless. We think this would make a really neat button. You can see a video of…
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Ebay is Boring Compared to New Electronics Auction
Burbank, California – Muulu (muulu.com) is growing in popularity as a cheaper alternative to eBay. Why? Because the average winning bid for new electronics items, like iPhones, game systems, and iPods, is substantially lower on Muulu than on Ebay. People pay for bids. These payments buy down the possible winning price of the item being auctioned until it is won for well below wholesale price. Other electronic items include HDTVs, laptops, desktop computers, and GPS systems.
The biggest thing that draws people to Muulu is the insane deals. People can win a new Apple iPod Touch for $90, a new…
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Automated Paintball Sentry
Reader, [Ben Godding], sends in the video for his senior design team’s automated paintball sentry. The frame is made of plasma cut aluminum. The paintball gun uses a custom hopper mounted remotely from the gun body. It has two webcams offering a 160 degree field of vision, and the image processing is done by a dual core pentium CPU booting windows xp off a compact flash card. The computer interfaces with the 1/4scale RC servos using a PIC24. The paintball sentry can either be configured via a computer GUI when a monitor is available or a baclkit keypad and…
