Audio Spectrum Analyzer
As complicated as I thought this would be, this circuit is using the basic fundamentals of electronics and algebra. The only hard part is perfecting it and expanding it. Click here to see the finished project.
Resistor
MintyBoost USB Charger Kit v3.0
Safely and effectively charge your USB-powered devices when you are away from your computer with this handy charger! Please note: There have been reports that the Minty Boost has issues charging the iPhone 3GS.
555 Timer Ball Whacker
This project uses a simple 555 timer chip and a feedback loop to control a servo-controlled wooden arm. Whenever an object comes close to a photosensor mounted on the end of the arm, it blocks the amount of light detected, which triggers the arm to swat the object away.
ESP/psi Testing Lamp
Albert Einstein once wrote that God does not play dice with the universe. To which Niels Bohr (or Enrico Fermi) reportedly replied, “Stop telling God what to do with his dice.” Here’s a mood lamp that expresses these dice as 4 multicolored cubes that blink randomly, with true randomness — not the deterministic, pseudo-random chaos […]
WireFinder 9000
By Christie, Jim, John, and Terry Noe Our dog, Maggie, loves to run around in our big yard. But how do we fence her in? Building a 500-foot fence is expensive and unsightly, so we use an “invisible fence.” This is a buried wire that runs around the edge of our yard. Maggie wears a […]
Light Theremin
Anyone who’s shivered in the dark at a scary movie or laughed at the unintentional cheese-ball of a bad sci-fi (paging Ed Wood) knows the eerie sounds of the theremin. In the classic theremin design, two antennas control pitch and volume, and you play the instrument by moving your hands near the antennas without touching […]
Whack-a-Mole Game
Jim Chen designed an excellent electronic “Whack-a-Mole” game using 555 timers, LEDs, and bent-diode touch sensors, that you can build on a solderless breadboard
