On/off Electric Motor Control Circuits

Textbook

An electric motor is often used as a discrete control element in a…

Use of Line Reactors

Textbook

Regulating the electric power sent to an electric motor is a task…

Rotating Magnetic Fields in Three-phase AC Induction Motors

Textbook

The following animation shows how the “rotating” magnetic…

Controller Output Current Loops

Textbook

The simplest form of 4-20 mA current loop is the type used to…

AC Motor Braking

Textbook

There are several different methods useful for causing an AC induction…

VSD and VFD Motor Drive Features

Textbook

Modern DC and AC motor drives provide features useful when using…

DC Motor Speed Control

Textbook

DC electric motors generate torque by a reaction between two magnetic…

Understanding How Three-phase Electric Motors Work

Textbook

The key to understanding how three-phase electric motors work is to…

AC Motor Speed Control

Textbook

AC induction motors are based on the principle of a rotating magnetic…

Cascade Control

Textbook

A simple control system drawn in block diagram form looks like this:…

Limit, Selector, and Override Controls

Textbook

Another category of control strategies involves the use of signal…

Metric Prefixes and Prefix Scale

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Fluid Power Systems

Textbook

Given the ability of pressurized fluids to transmit force over long…

Basics of Electrical Current

Textbook

Current is the name we give to the motion of electric charges from a…

The s Variable: Euler’s Relation and Phasor Expressions of Waveforms

Textbook

A powerful mathematical concept useful for analyzing practically any…

Instrument Identification Tags

Textbook

Up until this point, we have explored various types of instrumentation…

Process and Instrument Diagrams

Textbook

The next level of detail is the Process and Instrument Diagram, or…

Phasor Analysis of Transformer Circuits

Textbook

Three-phase AC is the dominant mode of electric power generation and…

Analog to Digital Conversion and ADCs

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In order to provide an interface between the internal (digital) world…

Circuit Breakers and Disconnects

Textbook

Circuit breakers are the “final control elements” of the…

Relation Control

Textbook

A control strategy similar to ratio control is relation control. This…

Proportional-only Offset

Textbook

A fundamental limitation of proportional control has to do with its…

LRV and URV Settings, Digital Trim (Digital Transmitters)

Textbook

The advent of “smart” field instruments containing…

Digital Data Communication Theory

Textbook

One of the great benefits of digital technology is the ability to…

Analog Electronic PID Controllers

Textbook

Although analog electronic process controllers are considered a newer…

Understanding the Calculus Concepts of Differentiation and Integration

Textbook

The following animation shows the calculus concepts of differentiation…

AC Motor Speed Control

Textbook

AC induction motors are based on the principle of a rotating magnetic…

Overpressure Protection Devices

Textbook

Fluid pressure exerts force on any surface area it contacts, as…

Proper Care and Feeding of Pneumatic Instruments

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Perhaps the most important rule to obey when using pneumatic…

Numerical Integration

Textbook

As we have seen, the concept of integration is finding the…

Control Valve Sizing

Textbook

When control valves operate between fully open and fully shut, they…

Error Corrections

Textbook

Abdelaziz, Ahmed (June 2014) Identified numerous typographical errors…

Design-based Fortifications

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A design-based fortification is one rooted in technical details of…

Practical Measures of Reliability

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In reliability engineering, it is important to be able to quantity the…

Circuit Failure Analysis

Textbook

Perhaps the most valuable skill an instrument technician can possess…

Introduction to Power System Automation

Textbook

Those familiar with industrial instrumentation will find much within…

Mechanical Vibration Switches

Textbook

A much simpler alternative to continuous vibration sensors…

P, I, and D Responses Graphed

Textbook

A very helpful method for understanding the operation of proportional,…

Resistance, Reactance and Impedance

Textbook

Resistance (\(R\)) is the dissipative opposition to an electric…

Vibration Monitoring Hardware

Textbook

The following photograph shows a large air blower in a wastewater…

Pneumatic Sensing Elements

Textbook

Most pneumatic instruments use a simple but highly sensitive mechanism…

Pilot Valves and Pneumatic Amplifying Relays

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Self-balancing mechanisms consisting solely of a baffle/nozzle…

An Analogy for Calibration Vs Ranging

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The concepts of calibration (trimming) and ranging are often difficult…

Distance (21) Protection

Textbook

A form of protection against faults on long-distance power lines is…

Quantitative PID Tuning Procedures

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A quantitative PID tuning procedure is a step-by-step approach leading…

Understanding Electrical Power Grids

Textbook

The term “grid” refers to the conductors and equipment…

Feedforward Control

Textbook

“Feedforward” is a rather under-used control strategy…

Self-regulating, Integrating, and Runaway Process Characteristics

Textbook

Perhaps the most important rule of controller tuning is to know the…

4 to 20 mA Analog Current Signals

Textbook

The most popular form of signal transmission used in modern industrial…

Zero and Span Adjustments (Analog Instruments)

Textbook

The purpose of calibration is to ensure the input and output of an…