Approximately 35% is new or revised material in the book plus 60 projects on the books web site hosted by the author. The content and structure of the book has been very well received, therefore this revision will maintain the bulk of original material and enhance it by adding hands-on practice and conceptual background information. All projects accessed at www.buildinggadgets.com will use 4/c photos to enhance the visual appeal of the on line projects. Two-color sidebars highlight new content: Using the Multimeter, Using the Breadboard, Inside the Resistor, and new projects, along with the sidebars: a Full Diode Project, not just an experiment and a Zener Diode Project, along with a Transistor Project, Bipolar Transistor, The Transistor Switch Project. Also, The JFET Project, Using a Function Generator, Using an Oscilloscope, Inside the Capacitor, The High Pass Filter Project, Inside the Inductor, The IC Filter Project. The Bandpass Filter project, The Transistor Amplifier Project, The Stable Amplifier Project, Inside the Amplifier, The Operational Amplifier Project, The Colpitts project, Inside the Oscillator, The Simple Oscillator Project, Designing an Oscillator Project and numerous other new projects.