An oscilloscope is a type of electronic test instrument that allows signal voltages to be viewed, usually as a two-dimensional graph of one or more electrical potential differences (vertical axis) plotted as a function of time or of some other voltage (horizontal axis). Although an oscilloscope displays voltage on its vertical axis, any other quantity [...]

In this post, TechshopJim will show you how to etch a circuit board with about a tablespoon of ferric chloride etching solution and a 2 inch square sponge. You will be amazed as the exposed copper on the PCB disappears before your eyes, and your board is completely etched in a minute or less! Source: [...]

This post will show you how to make a thermometer that displays the temperature of the air. It’s not the most accurate thermometer in the world, but for this price and the fact that it was homemade… Source:DemonDomen

This is a automatic battery charger, after completing the charge it turns off automatically. It runs on AC power but you can also run it with DC power. Its not my idea or my invention, I got it from net. After understanding the circuit I built it and it works fine. So try to built [...]

This device plugs in-line with the PS2 port and hijacks key presses. When a username is typed in, it records the following password. Source: shawnlankton

This is a PIC based system that implemented a closed-loop PID controller for position and speed control of two DC motors. In addition, the control loop could be adjusted to induce arcs. The system was designed as a peripheral for another processor so it also had an SPI command interface that allowed it to be [...]

the automated drink maker has a remote interface that sends the command for drink selection via wireless system to the main controller.The Automatic wireless drink mixer is a final project for a group from the University of Washington’s Electrical Engineering department (ee478). Source: borntechie

One very important Part of a Tube Amplifier is the Power Supply. It is crucial for the quality of the whole system. Especially beginners encounter problems like Hum or Drift that can become quite annoying. But resue is ahead: The following circuit uses a modern Mosfet to deliver a stable and virtually Hum-free voltage to [...]

This is a simple project, but one I hope you will find useful. Recent upgrades of 2 of my PC’s with bang-up-to-date motherboards, have demonstrated a need for USB ‘A’ socket headers, either to fit on a standard PC Component plate, or a spare blanking panel on the front of the PC. I’ve tried sourcing [...]

This mini-project is the main power-supply for the Valve Crunch/Tremelo floor pedal presented elsewhere on Connectable  site. Since the PSU is a separate unit, and may be of use elsewhere I decided to document it apart from the pedal. The unit expects a 12v input at X1 – this was a cheap wall-wart in the [...]