Power Education

TI is unleashing the power of silicon carbide with a new, verified reference design that provides an overview on how to implement a three-level, three-phase SiC based DC:AC grid-tie inverter stage. In this video you will learn the advantages of a three-level topology; what TI technology is driving the SiC MOSFETs;  how and where are we sensing V & I; what is behind the digital power controller; and what efficiency and power density levels you can achieve with this design. Tune in as TI discusses this innovative technology at the Applied Power Electronics Conference.

In this experiment, we will aim to learn about the following concepts: • Capacitor charging action • Capacitor discharging action • Time constant calculation • Series and parallel capacitance Capacitor Charging and Discharging Experiment Parts and Materials To do this experiment, you will need the following: • 6-volt battery • Two large electrolytic capacitors, 1000 µF minimum (Radio Shack catalog # 272-1019, 272-1032, or equivalent) • Two 1 kΩ resistors • One toggle switch, SPST (“Single-Pole, Single-Throw”) Large-value capacitors are required

As an instructor of electronics, I am called upon frequently to help students troubleshoot their malfunctioning lab circuits. When I approach a student’s self-built circuit to troubleshoot it, though, I often begin the process with a very different mindset than if I were troubleshooting a malfunctioning circuit on a real job site. Aside from different safety considerations and a very different work environment, what else do you think I

Since three-phase is used so often for power distribution systems, it makes sense that we would need three-phase transformers to be able to step voltages up or down. This is only partially true, as regular single-phase transformers can be ganged together to transform power between two three-phase systems in a variety of configurations, eliminating the requirement for a special three-phase transformer. However, special three-phase transformers are built for those tasks

PARTS AND MATERIALS Multimeter, digital or analog Assorted batteries One light-emitting diode (Radio Shack catalog # 276-026 or equivalent) Small “hobby” motor, permanent-magnet type (Radio Shack catalog # 273-223 or equivalent) Two jumper wires with “alligator clip” ends (Radio Shack catalog # 278-1156, 278-1157, or equivalent) A multimeter is an electrical instrument capable of measuring voltage, current, and resistance. Digital multimeters have numerical displays, like digital clocks, for indicating the quantity of voltage,

Because batteries create current flow in a circuit by exchanging electrons in ionic chemical reactions, and there is a limited number of molecules in any charged battery available to react, there must be a limited amount of total charge that any battery can motivate through a circuit before its energy reserves are exhausted. Battery capacity could be measured in terms of a total number of electrons, but this would be

Over the course of the next few chapters, you will learn that AC circuit measurements and calculations can get very complicated due to the complex nature of alternating current in circuits with inductance and capacitance. However, with simple circuits (figure below) involving nothing more than an AC power source and resistance, the same laws and rules of DC apply simply and directly. AC circuit calculations for resistive circuits are the

This calculator computes for the capacitor charge time and energy, given the supply voltage and the added series resistance.

Diodes can perform switching and digital logic operations. Forward and reverse bias switch a diode between the low and high impedance states, respectively. Thus, it serves as a switch. Logic Diodes can perform digital logic functions: AND, and OR. Diode logic was used in early digital computers. It only finds limited application today. Sometimes it is convenient to fashion a single logic gate from a few diodes. Diode AND gate

How is it possible to assign a fixed value of voltage or current (such as “120 volts”) to an AC electrical quantity that is constantly changing, crossing 0 volts, and reversing polarity?

This tool calculates a capacitor's reactance for a given capacitance value and signal frequency.

PARTS AND MATERIALS Steel flat bar, 4 pieces Miscellaneous bolts, nuts, washers 28 gauge “magnet” wire Low-voltage AC power supply “Magnet wire” is small-gauge wire insulated with a thin enamel coating. It is intended to be used to make electromagnets, because many “turns” of wire may be wrapped in a relatively small-diameter coil. Any gauge of wire will work, but 28 gauge is recommended so as to make a coil with as many

Current Source It is possible through the use of electronic amplifiers to design a circuit outputting a constant amount of current rather than a constant amount of voltage. This collection of components is collectively known as a current source, and its symbol looks like this: A current source generates as much or as little voltage as needed across its leads to produce a constant amount of current through it. This

Using an electrical meter safely and efficiently is perhaps the most valuable skill an electronics technician can master, both for the sake of their own personal safety and for proficiency at their trade. It can be daunting at first to use a meter, knowing that you are connecting it to live circuits which may harbor life-threatening levels of voltage and current. This concern is not unfounded, and it is always

A common topology for DC-AC power converter circuits uses a pair of transistors to switch DC current through the center-tapped winding of a step-up transformer, like this: In order for this form of circuit to function properly, the transistor “firing” signals must be precisely synchronized to ensure the two are never turned on simultaneously. The following schematic diagram shows a circuit to generate the necessary signals: Explain how this circuit

PARTS AND MATERIALS One N-channel junction field-effect transistor, models 2N3819 or J309 recommended (Radio Shack catalog # 276-2035 is the model 2N3819) Two 6-volt batteries One 10 kΩ potentiometer, single-turn, linear taper (Radio Shack catalog # 271-1715) One 1 kΩ resistor One 10 kΩ resistor Three 1.5 kΩ resistors For this experiment you will need an N-channel JFET, not a P-channel!experiment you will need an N-channel JFET, not a P-channel! Beware that not all transistors

There are three basic factors of capacitor construction determining the amount of capacitance created. These factors all dictate capacitance by affecting how much electric field flux (relative difference of electrons between plates) will develop for a given amount of electric field force (voltage between the two plates): Plate Area All other factors being equal, greater plate area gives greater capacitance; less plate area gives less capacitance. Explanation: Larger plate area

We're in section 9.2, Power Supply Applications. The reason we're looking at power supplies is because they are a major use of diodes. Nearly all computers have some sort of power supplies. Now a power supply circuit must do several things. One of them is to convert AC line voltage into a DC voltage required by the circuit. They also must reduce the AC voltage to a lower value and they

PARTS AND MATERIALS Power transformer, 120VAC step-down to 12VAC, with the center-tapped secondary winding (Radio Shack catalog # 273-1365, 273-1352, or 273-1511). Terminal strip with at least three terminals. Household wall-socket power plug and cord. Line cord switch. Box (optional). Fuse and fuse holder (optional). Power transformers may be obtained from old radios, which can usually be obtained from a thrift store for a few dollars (or less!). The radio would

Ladder diagrams are specialized schematics commonly used to document industrial control logic systems. They are called “ladder” diagrams because they resemble a ladder, with two vertical rails (supply power) and as many “rungs” (horizontal lines) as there are control circuits to represent. If we wanted to draw a simple ladder diagram showing a lamp that is controlled by a hand switch, it would look like this: The “L1” and “L2”

Most students of electricity begin their study with what is known as direct current (DC), which is electricity flowing in a constant direction, and/or possessing a voltage with constant polarity. DC is the kind of electricity made by a battery (with definite positive and negative terminals), or the kind of charge generated by rubbing certain types of materials against each other. Alternating Current vs Direct Current As useful and