LED Sound Meter

In this guide you will learn to created an array of LEDs that visually represent the volume picked up by an electret microphone. You will learn how to wire 3 different circuits which are the LED array (which is really many individual circuits), the microphone, and a button which can be used... Read more »

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... Read more »

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... Read more »