Richard Wolfson

Understand the math behind two basic rules that allow op-amps to leverage the magic of negative feedback: no current flows into op-amp inputs, and with negative feedback, V+ = V -. See how these rules allow op-amps to tame near-infinite gain in a circuit down to the exact amplification you want.

By combining logic gates and positive feedback, obtain circuits with two stable states. These "flip-flop" circuits "remember" their current states until they are forced into the opposite state. Learn the inner workings of several types of flip-flops as they lay the foundations for memory circuits.

Because we live in an analog world - sound, time, temperature, speed, and light are all analog phenomena - it's important to be able to convert outputs of digital circuits into analog signals that we can perceive. Discover two digital-to-analog converters (DACs): weighted-resistor DACs, and the delta-sigma DACs that provide high-resolution audio for our smartphones and mp3 players.

Semiconductors make possible the transistors at the heart of electronics, including integrated circuits and computers. Learn how the atomic configuration of semiconductors makes them unique, and how engineers adjust their properties to make two types of semiconductors - P and N. Witness the critical role that PN-junctions play in semiconductor devices.

Flip-flops can be connected together to create counting circuits. Examine the circuitry behind 2-bit, n-bit, and decade counters, then see how the interruption of a light beam can be used in conjunction with such a circuit to keep count of people walking by or products moving along an assembly line.

See how distinctly different electrical circuits can implement basic logic operations, and how simple logic gates come together to form complex logic circuits, ultimately including computers. Return to transistors to see how both BJTs and MOSFETs are used to implement logic gates, the latter in an arrangement called Complementary Metal Oxide Semiconductor (CMOS).

From familiar audio equalizers we use to crank the bass or reduce hiss, to cell phone towers that need to separate calls coming in on adjacent channels, filtering electronic signals is often essential. Dive further into the critical role that capacitors play in electronic filters.

Transistors in all forms fundamentally do the same thing: they allow one electronic circuit to control another. Review the concept of electronic control, and study field effect transistors (FETs) as well as bipolar junction transistors (BJTs). See how the bipolar junction transistor can be used as a simple switch.

What is the difference between electricity and electronics? Begin your study of modern electronics by examining this distinction, and observe how electronics use the basic properties of electric circuits in a more sophisticated way. Witness firsthand how resistance is described with Ohm's law, and learn how to measure electric power.

Learn why large gain - infinite gain, in fact - as well as low output resistance and high input resistance are characteristics of the ideal amplifier. See how an integrated-circuit operational amplifier, or "op-amp," puts all these things together and also how the op-amp can be used as a simple comparator.