
There are a lot of electrical devices that only have two settings: ON and OFF. For a many of these, it would be helpful if you could adjust the output with an external circuit.
So in this project, I am going to show you how to make an adjustable power outlet. This circuit acts as an external dimmer and can be used to adjust the power on a variety of appliances such as Lamps, heaters, soldering irons, and hot glue guns.

BEAM robotics is about getting the most complex and interesting behaviors from the simplest circuits and components. The SunBEAM Seeker is a very simple LM386-based light-seeking robot based on Randy Sargent's classic "Herbie" BEAM design. Build this little bot and it will follow a black line traced on a white floor or, with the photosensors pointing upward as in this version, seek out the brightest light source in a room. It is also descended, in part, from our own Mousey the Junkbot, and adds a special tailwheel made from a roller-lever limit switch to make the robot automatically turn on when you set it down, and off again when you pick it back up.

The Data Dial Dashboard brings back the fun of old-school analog dial gauges while updating them with internet connectivity. In this project we will use an Arduino, Ethernet shield, and 3 servos to create a system for tracking global earthquake activity. The data is pulled from the USGS Real-time Data Feeds page. With a little hacking, it is easily adapted to track your unanswered e-mail count, the speed of your internet connection, the price of rice in Rhode Island, or any other data you can scrape off the 'net!