Richard Wolfson
Description
Learn how electronic devices "talk" to each other by using flip-flops to send computer "words" one bit at a time, and observe how recipient devices reassemble incoming bits using serial-to-parallel conversions. See how Universal Serial Bus (USB) connections transmit communications between devices, and how the T flip-flop is utilized as a frequency divider in quartz watches.
Description
Examine the nuances of alternating and direct currents, see how transformers use electromagnetic induction to transform voltage levels in AC circuits, and observe the role of diodes and capacitors in regulating current. See how the DC power supplies that charge our cell phones are constructed so that they convert alternating to direct current.
Description
Define what "feedback" means in electronics, and how it can be used in a circuit. Learn how negative feedback utilizes communication between the output and input of an amplifier, and how operational amplifiers use this phenomenon to create thought-controlled robotic arms, intelligent light bulbs, and optical tracking systems.
Description
Now that the versatility of negative feedback has been demonstrated, adjust the strength of negative feedback in op-amp circuits to build amplifiers with whatever gain you choose. Create an amplifier that sums two or more inputs, see a circuit that converts current to voltage, and explore the design and operation of an op-amp-based light meter.
Description
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.
Description
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.
Description
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).
Description
Electronic devices are fundamental to our global economy, improve our lives immeasurably, and underlie virtually every aspect of modern life. Yet very few of us have any idea of how electronic devices actually work. In fact, these increasingly complex devices operate on a few basic principles that are both fascinating and easy to understand.
Description
Discover how transistors can be used to increase voltage, current, or power of an electronic signal while faithfully reproducing the signal's time variation. See how biasing and load-line analysis play key roles in amplifiers, and help prevent distortion. Learn to design a simple one-transistor audio amplifier that increases the voltage of audio-frequency signals.
Description
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.
Description
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.
Description
Meet the battery! This marks your introduction to circuit diagrams, displaying the interconnected assemblages of electronic components that make a circuit function. Learn how to decipher these drawings, and see how components assembled in series or in parallel may interact differently depending on their configuration.
Description
Observe how circuit designers have formulated a wide array of schemes for converting analog signals to digitally encoded information. See how flash converters, integrating converters, and feedback converters use very different methods to accomplish the same goal, and weigh the situational costs and benefits of each.
Description
Explore peak detectors that "remember" the maximum voltage reached, as well as Schmitt triggers whose output retain their value until the input changes sufficiently to "trigger" a change in the output. Use these concepts to design a practical circuit: an alarm to warn if your freezer's temperature has been above freezing.
Description
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.
Description
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.
Description
Put your knowledge to use by building a complete audio amplifier. First, create a two-stage amplifier, then add capacitors to increase the amplification, or gain. Add a power output stage to drive a loudspeaker. Finally, add a volume control. In addition, learn how biasing with diodes can eliminate a subtle form of distortion.
Description
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.
