Transistor

Solar Buzzing Beetle

Solar Buzzing Beetle

In these instructions, I teach you how to make a vibrating little cute buzzing humming beetle robot. This is great for beginners because of the simple circuit and low parts cost.

Water Leak Detector

Water Leak Detector

The average life expectancy of a hot water heater is about 10 years, so it’s not a question of if it will leak — it’s simply a matter of when. In my part of the country, homebuilders have been installing these tanks in the attic. This saves space, but also means that if you don’t […]

USB Watchdog for Linux with Arduino

USB Watchdog for Linux with Arduino

A watchdog device monitors your computer to see if the OS is still running. If the system has locked up it will reset the system. High end servers come with built in watchdogs, for basic servers and workstations you can pick up a PCI card version for $100+ depending on features. Basic watchdog cards receive […]

Wearable Light Organ

Wearable Light Organ

This simple, wearable circuit uses an operational amplifier (or “op-amp”) chip to convert sound into light. An LM324 op-amp and a transistor boost input from a mini condenser microphone to light a series of LEDs. Watch it blink to the beat of your favorite music. Check out more Weekend Projects.

Treasure Finder

Treasure Finder

Who hasn’t dreamed about owning their own metal detector and searching for buried treasure, or at least a few dropped coins? In this project, we will build a metal detector based on a dual oscillator circuit. One oscillator is fixed, and the other varies depending upon the proximity of metal objects. The beat frequency between […]

ESP/psi Testing Lamp

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

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 […]