Negative feedback systems, in general, tend to cause confusion for…
A limit switch detects the physical motion of an object by direct…
Modern DC and AC motor drives provide features useful when using…
In order for any PID controller to be practical, it must be able to do…
A simple control system drawn in block diagram form looks like this:…
As discussed at the beginning of this chapter, instrumentation safety…
An electric motor is often used as a discrete control element in a…
In addition to directly performing logic functions, electromechanical…
There are several different methods useful for causing an AC induction…
Perhaps the most important rule of controller tuning is to know the…
The vast majority of PID controllers in service today are digital in…
The simplest form of 4-20 mA current loop is the type used to…
The simple PLC ladder diagram (LD) commands consist of contacts and…
The purpose of a control valve actuator is to provide the motive force…
Phasors are to AC circuit quantities as polarity is to DC circuit…
Virtually any mass above absolute zero temperature emits…
In the United States, the most common language used to program PLCs is…
Feedback Control System Components Before we begin our discussion on…
DC electric motors generate torque by a reaction between two magnetic…
Non-dispersive analysis, while newer in discovery than dispersive…
The term “grid” refers to the conductors and equipment…
At the next OSI Reference Model layer (layer 4) is a set of protocols…
Since we often use electricity to convey energy from one location to…
A temperature switch is one detecting the temperature of some…
The disadvantages of pneumatic instruments are painfully evident to…
Feedback Control System Components Before we begin our discussion on…
The Law of Continuity for fluids states that the product of mass…
Displacer level instruments exploit Archimedes’ Principle to…
All substances are comprised of various elements in various…
Learning PLC programming is a very important skill. If your job…
Fieldbus devices require far more attention in their initial setup and…
Area refers to the size of two-dimensional surface. Volume refers to…
Imagine a liquid-level control system for a vessel, where the position…
Every flow-measuring instrument exploits a physical principle to…
Tube, like pipe, is a hollow structure designed to provide an enclosed…
Electrical Resistance Resistance (\(R\)) is the dissipative opposition…
Many liquid substances undergo a process whereby their constituent…
Volumes could be written about poor diagnostic technique. The…
While 50 and 51 (instantaneous and time overcurrent) relay functions…
One very convenient feature of waves is that their properties are…
