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.

Learn the Power Formula We’ve seen the formula for determining the power in an electric circuit: by multiplying the voltage in “volts” by the current in “amps” we arrive at an answer in “watts.” Let’s apply this to a circuit example: How to Use Ohm’s Law to Determine Current In the above circuit, we know we have a battery voltage of 18 volts and a lamp resistance of 3 Ω.

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

PARTS AND MATERIALS Low-voltage AC power supply (6-volt output) Two 1N4001 rectifying diodes (Radio Shack catalog # 276-1101) Small “hobby” motor, permanent-magnet type (Radio Shack catalog # 273-223 or equivalent) Audio detector with headphones 0.1 µF capacitor One toggle switch, SPST (“Single-Pole, Single-Throw”) It is essential for this experiment that the low-voltage AC power supply is equipped with a center tap. A transformer with a non-tapped secondary winding simply will not work for

In many circuit applications, we encounter components connected together in one of two ways to form a three-terminal network: the “Delta,” or Δ (also known as the “Pi,” or π) configuration, and the “Y” (also known as the “T”) configuration. It is possible to calculate the proper values of resistors necessary to form one kind of network (Δ or Y) that behaves identically to the other kind, as analyzed from the terminal connections

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 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

This calculator calculates the RMS Voltage value from either the peak voltage, the peak-to-peak voltage, or the average voltage.

The first, and perhaps most important, the relationship between current, voltage, and resistance is called Ohm’s Law, discovered by Georg Simon Ohm and published in his 1827 paper, The Galvanic Circuit Investigated Mathematically. Voltage, Current, and Resistance An electric circuit is formed when a conductive path is created to allow electric charge to continuously move. This continuous movement of electric charge through the conductors of a circuit is called a

Let’s take the three-phase alternator design laid out earlier (Figure below) and watch what happens as the magnet rotates. Three-phase alternator The phase angle shift of 120o is a function of the actual rotational angle shift of the three pairs of windings (Figure below). If the magnet is rotating clockwise, winding 3 will generate its peak instantaneous voltage exactly 120o (of alternator shaft rotation) after winding 2, which will hits its

PARTS AND MATERIALS Paper tube, from a toilet-paper roll Bar of iron or steel, large enough to almost fill diameter of paper tube 28 gauge “magnet” wire Low-voltage AC power supply Incandescent lamp, rated for power supply voltage CROSS-REFERENCES Lessons In Electric Circuits, Volume 1, chapter 14: “Magnetism and Electromagnetism” Lessons In Electric Circuits, Volume 1, chapter 15: “Inductors” Lessons In Electric Circuits, Volume 2, chapter 3: “Reactance and Impedance—Inductive” LEARNING OBJECTIVES Effects of magnetic permeability

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?

Define the following terms: energy, work, and power.

In addition to voltage and current, there is another important parameter related to electric circuits: power. First, we need to understand just what power is before we analyze it in any circuits. What is Power and How Do We Measure It? Power is a measure of how much work can be performed in a given amount of time. Work is generally defined in terms of the lifting of a weight

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

Suppose a 12 volt lead-acid battery has an internal resistance of 20 milli-ohms (20 mΩ): If a short-circuit were placed across the terminals of this large battery, the fault current would be quite large: 600 amps! Now suppose three of these batteries were connected directly in parallel with one another: Reduce this network of parallel-connected batteries into either a Thévenin or a Norton equivalent circuit, and then re-calculate the fault current available at

Wiring Color Codes Infographic. Released under the Creative Commons Attribution-ShareAlike License Looking for Wiring & Resistor Calculators? View our Wire & Resistor calculators in our Tools section. Basic Wire Color Code Information by Region Many of the wire identifications standards rely on color codes. Which standard should you be using for your project? It depends on your location, voltage, and other important factors. Note: Older installations may use different color

In the chapter on mixed-frequency signals, we explored the concept of harmonics in AC systems: frequencies that are integer multiples of the fundamental source frequency. With AC power systems where the source voltage waveform coming from an AC generator (alternator) is supposed to be a single-frequency sine wave, undistorted, there should be no harmonic content . . . ideally. This would be true were it not for nonlinear components. Nonlinear components draw current

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

Label where each of the following electrical quantities would be found in both the “Y” and “Delta” three-phase configurations: Phase voltage Line voltage Phase current Line current In which circuit (Y or Delta) are the phase and line currents equal? In which circuit (Y or Delta) are the phase and line voltages equal? Explain both answers, in terms that anyone with a basic knowledge of electricity could understand. Where phase

PARTS AND MATERIALS Low-voltage AC power supply (6-volt output) 6-volt battery One 1N4001 rectifying diode (Radio Shack catalog # 276-1101) Small “hobby” motor, permanent-magnet type (Radio Shack catalog # 273-223 or equivalent) Audio detector with headphones 0.1 µF capacitor (Radio Shack catalog # 272-135 or equivalent) The diode need not be an exact model 1N4001. Any of the “1N400X” series of rectifying diodes are suitable for the task, and they are quite easy