General

• Decibelskalan - This table shows voltage levels and corresponding dBV and dBu values. The text on the page is in Swedish but the decibel table is useful without understanding Swedish.
• Electromagnetic Spectrum
• Energy and Electrical Power Tutorials at Howstuffworks
• How things work - physical explanations how common things work
• How to cheat with dBs ... an intuitive approach - Decibels are relatively simple, yet many engineers seem to have trouble doing the calculations mentally, here are few tips to make them simpler
• SI Units
• Temperature Conversion - conversion between Fahrenheit and Celsius degrees
• The Printed Circuit Board Primer - A fine printed circuit board (PCB) is a mixture if high art, and solid engineering. Here is a short primer on what goes into the making of a PCB, the terminology, and the features that enhance reliabity, and lower cost.
• The Vacuum Tube Era (1905 - 1948) - electronics history document
• Twisted Pair - a site dedicated to those in pursuit of an understanding of Electronics
• Unit Conversios
• Using a multimeter - A meter is a measuring instrument. An ammeter measures current, a voltmeter measures the potential difference (voltage) between two points, and an ohmmeter measures resistance. A multimeter combines these functions, and possibly some additional ones as well, into a single instrument.
• Using the Multimeter to Measure Voltage and Resistance - Multimeters are commonly used to measure voltage and resistance between two points. Current is rarely measured because you must alter the circuit to measure the current.

Digital electronics

Basics

• Asymmetrical noise margins - details on interfacing digital ICs
• Doing it Digital - Why then, do hobbyists (and small businesses!) often shy away from digital techniques?
• Introduction to Boolean Algebra - check also Basic Boolean Algebra Manipulation
• Introductory Digital Electronics - on-line tutorial
• Leroys Engineering Web Site Logic Design Information
• Logic Operator - description of basics of AND, OR, NOR, NAND and NOT gates
• Some logic circuits using discrete components
• State Machine Analysis

Digital IC characteristics

• About the differences between the TTL families - General characteristics of the TTL families (HC, HCT*, LS*...)
• ECL - Emitter Coupled Logic - A quick definition for general consumption
• Ground Bounce in CMOS Devices - The high edge speeds and clock frequencies of advanced CMOS technology can produce unwanted oscillations during logic level transitions resulting in random logic bit errors.
• Integrated Circuits and Timing
• Low Power Schottky TTL logic levels
• Standard TTL logic levels
• Understanding Computers - introduces signed and unsigned binary numbers, two's complements, the carry, borrow, and overflow flags, and the effect of shifting signed and unsigned values, article is in pdf format

Memory

• How Memory Works

Theory

• A Basic Introduction to Filters - active, passive and switched capacitor filters, document in PDF format
• Alex's Electronic Resource Library - collection of electronics tutorials
• Basic Analog for Digital Designers - tutorial in pdf format
• Basics of Electronics - basics of electricity and charge
• Cable impedance - what is cable characteristic impedance
• Characteristic Impedance of Cable at High and Low Frequencies
• Cource notes for power electronics
• Electronics Concepts - course on electronics theory
• Elements of AC Electricity - Basic Electronics on-line tutorial
• Electronics Information Files - pages aimed at beginners, includes simple circuit and some useful free teaching software
• Filters - examples of very many different filter types, good page for filter design information
• International Rectifier Application Training Guide - basic circuit theory, semiconductor basics, applications
• Laws of electronics - Ohm's Law and Kirchhoff's Laws
• Ohm's Law - equations, description and examples
• Piezoelectricity education - includes basic information, application data, FAQs, introduction to piezo transducers, piezo history and recommended reading list
• Power factor - it is more than just cos(Phi)
• Practical Analog Design - refresher on op-amps
• Semiconductor Physics for Solid State Electronics
• The Smith Chart - an RF engineering aid by Phillip Smith of RCA many years ago
• Transistors and amplification
• Understanding Electricity - an analogy with water