All posts on April, 2008
Posted on 29 Apr 2008
This is a really cheap and probably illegal shortwave transmitter, don’t build it. It just feeds the output from an LM386 audio amplifier directly into the power pin of a crystal oscillator can to produce AM-modulated shortwave radio frequencies. This works better than one might expect — this particular oscillator seems to provide a stable waveform with voltages anywhere from 2.0v to 5.0v![more]
Posted on 29 Apr 2008
This page shows you to build a lamp that can change color, and can be controlled by a computer. Simple Python and C programs for your PC or Mac are provided that let you program color patterns into the lamp. Implementing the weather forecast and other ideas are then up to you. Web scraping with wget is easy if you understand a scripting language. The whole project should cost under 100 euro, half of which is for the lamp (glass ball, LED module, microcontroller, and odds and ends), and the other half for the flash programmer if you don’t have one. [more]
Posted on 29 Apr 2008
Light chaser circuits can be used to create lighting animation sequences and have been used in the past to attract attention for advertising and promotion, such as the marquee at the local movie theater. In addition, they can be used to produce pleasing effects for entertainment as well. This article is about how they work and how you can make use of them. Once a high priced item, the technology has now gotten to the point where everyone can afford the parts to build them. They may be just what you need for your next gathering or party. [more]
Posted on 29 Apr 2008
Wayne Eggert writes:This is an Atari cartridge that has been modified with a 24-pin DIP (dual inline package) socket. I originally intended on using this for experimenting with Atari programming and burning some homemade games. After purchasing several desoldering tools, I finally found a worthwhile one at Radio Shack and it cut down considerably on the time invested on taking the old chip out of the Atari cartridge. I then just soldered in the new ZIF (zero insertion force) 24-pin DIP socket and then tested it with the old chip to make sure everything was still in working order. That was the easy part — following soldering the socket in, I cut several traces on the board and soldered a hex inverter in so that I could then use a 2532 eprom with the board. I tested the cartridge several times and was able to get it working with the 2532 eprom relatively easily 
It successfully loaded up a Kaboom! rom I burned onto the eprom just fine.[more]
Posted on 29 Apr 2008
Miami Mike writes:Recently our club’s winch went out of control and destroyed a glider. The operator took his foot off the pedal but the motor kept running, folding the glider’s wings and slamming it into the ground. Fortunately the winch had a cutoff switch and we were finally able to stop it. It happened because our winch only had one solenoid and the contacts inside had gotten stuck together. We now have two new solenoids wired in series, and I’ve designed a small device to help prevent this sort of thing from happening again.[more]
