Welcome to All About Circuits!

This site provides a series of online textbooks covering electricity and electronics. The information provided is great for both students and hobbyists who are looking to expand their knowledge in this field. These textbooks were written by Tony R. Kuphaldt and released under the Design Science License.

Please keep in mind that the textbooks are not complete.
You may find missing pages and chapters as you browse. The books are a continuous piece of work, and will be updated over time.

Interested in contributing to the textbooks? Please click here.


  • Volume I - DC
        Basic Concepts of Electricity, OHM's Law, Electrical Safety, Scientific Notation...
  • Volume II - AC
        Basic AC Theory, Complex Numbers, Reactance and Impedance, Resonance...
  • Volume III - Semiconductors
        Amplifiers and Active Devices, Solid-State Device Theory, Diodes and Rectifiers...
  • Volume IV - Digital
        Numeration Systems, Binary Arithmetic, Logic Gates, Switches...
  • Volume V - Reference
        Conversion Factors, Resistor Color Codes, Math References, Periodic Table...
  • Volume VI - Experiments
        Test Equipment, DC Circuits, AC Circuits, Discrete Semiconductor Circuits...

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