An in-depth explanation of the fundamental concept of voltage. Covers voltage polarity, ground, and voltage measurement. A Test Your Knowledge! section is included to enhance the learning process.
An in-depth explanation of the fundamental concept of Current. Covers current direction, current measurement, and the relationship between current and voltage. A Test Your Knowledge! section is included to enhance the learning process.
Resistance characterizes the loss of energy associated with passing an electrical current through a conductive element. A high resistance corresponds to a large energy loss associated with current passage through a material, while low resistance corresponds to small energy loss associated with current passage through a material.
Periodic signals are more commonly identified by their frequency (usually abbreviated as f ), rather than their period. The frequency of a signal is the inverse of the period. The frequency of a signal tells us how many times the signal repeats itself during one second.
Sinusoids are an extremely important category of time-varying functions (or signals) and are used in many situations: In the electrical power industry sinusoids are the dominant signal used to transfer power. In communication systems (cellular telephones, radio signals, etc.) the so-called carrier signals are sinusoidal. Vibrations in mechanical systems are a common source of failure—the stresses caused by these vibrations are commonly analyzed in terms of sinusoids.
A sinusoidal sweep is a sinusoid whose frequency varies with time. Sinusoidal sweeps have practical applications in the testing of engineering systems. By applying a sinusoidal sweep to a system, we can measure the system's response to sinusoids of various frequencies. These measured responses can be used to predict the system's response to other inputs.
Modulated signals are composed of a carrier signal which is modified in some way based on another signal, generally called the baseband signal. The baseband signal refers to the original range of a signal before it is modulated to a different frequency range. Two primary modulation approaches are amplitude modulation and frequency modulation.
Explains the importance and basic features of the digital multimeter, including a terminology section.
Detailed instructions on how to measure current using a digital multimeter. This topic page also explains the several different settings on a DMM. Includes a Test Your Knowledge! section to practice the material covered.
Custom waveforms are represented as a series of samples—essentially, the samples provide a list of successive values in the waveform. The Arbitrary Waveform Generator (AWG) of the EE board constructs a waveform from these sampled points by assuming that the value of the function is constant between the given points.
Oscilloscope triggering allows us to assign a “zero time” to a particular feature on the signal. That feature gets placed on the same point on the plot window every time the oscilloscope screen updates; if the signal repeats itself based on this feature, the oscilloscope will display the same section of the signal every time the screen updates, making the signal appear to be unchanging.
.wav files are a common format for storing audio data, though other types of data are sometimes saved in this format. WAVE files are uncompressed —this results in relatively high quality audio signals, but at the expense of larger file sizes than would result from compressing the data.
The fundamental purpose of an oscilloscope is to measure and display voltages as a function of time. A plot of the voltages vs. time is provided in the main waveform window of the oscilloscope. The horizontal axis of the waveform window is time, and the vertical axis is voltage. The user can control the waveform display by adjusting these axes.
Oscilloscopes typically provide multiple approaches to acquiring and displaying data. The two most common and most distinct approaches are continuous acquisition and single-sequence acquisition. This topic page explains each approach.
Detailed instructions on how to measure voltage using a digital multimeter. This topic page also explains the several different settings on a DMM. Includes a Test Your Knowledge! section to practice the material covered.
Detailed instructions on how to measure resistance using a digital multimeter. This topic page also explains the several different settings on a DMM. Includes a Test Your Knowledge! section to practice the material covered.
Circuit elements in lumped parameters circuits are connected at nodes. Identification of circuit nodes will be extremely important to us when we are creating and analyzing circuits. Every node has a single unique voltage, so there can be no voltage drops (and thus no circuit elements) within a node. Perfect conductors do not cause voltage drops, so a node can contain perfect conductors.
Circuit elements are commonly categorized as either passive or active. A circuit element is passive if the total amount of energy it delivers to the rest of the circuit (over all time) is non-positive. (Passive elements can temporarily deliver energy to a circuit, but only if the energy was previously stored in the passive element by the circuit.) An active circuit element has the ability to create and provide power to a circuit from mechanisms external to the circuit.
When creating an electrical circuit, the fundamental goal is to apply voltages to the circuit such that the current is directed to perform some useful task. In order to do this, it is absolutely necessary to keep track of the voltage polarity relative to the current direction. he sign convention used by electrical engineers is the passive sign convention—so called since it applies to passive circuit elements.
An electrical system is often used to drive a non-electrical system (in an electric stove, for example, electric energy is converted to heat). Interactions between electrical and non-electrical systems are often described in terms of power. Electrical power associated with a particular circuit element is the product of the current passing through the element and the voltage difference across the element.
Kirchhoff's current law and Kirchhoff's voltage law are the basis for analysis of lumped parameter circuits. These laws, together with the voltage-current characteristics of the circuit elements in the system, provide us with the ability to perform a systematic analysis of any electrical network. Kirchhoff's current law (commonly abbreviated in these exercises as KCL) states: The algebraic sum of all currents entering (or leaving) a node is zero.
KVL depends upon the concept of a loop. A loop is any closed path through the circuit which encounters no node more than once. Essentially, to create a loop, start at any node in the circuit and trace a path through the circuit until you get back to your original node.
This exercise uses concepts introduced in our experiment relative to implementing circuits with a single source.
This exercise uses concepts introduced in our experiment relative to implementing circuits with a single source.