What is Weighfeeders ?

A special type flowmeter suited for powdered or granular solids is the weighfeeder. One of the most common weighfeeder designs consists of a conveyor belt with a section supported by rollers coupled to one or more load cells, such that a fixed length of the belt is...
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How to speed control of AC Motor ?

AC induction motors are based on the principle of a rotating magnetic field produced by a set of stationary windings (called stator windings) energized by AC power of different phases. The effect is not unlike a series of blinking light bulbs which appear to “move” in one...
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How to speed control of DC motor ?

DC electric motors generate torque by a reaction between two magnetic fields: one field established by stationary “field” windings (coils), and the other by windings in the rotating armature. Some DC motors lack field windings, substituting large permanent magnets in their place so that the stationary magnetic field...
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How to calibrate an RTD ?

Introduction:-There are two types of calibrations applicable to PRTs—characterization and tolerance testing. The type of calibration to perform is determined by the way in which the UUT is to be used and the accuracy required by the user. Characterization is the type of calibration in which the unit...
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Feedforward control

  Feedback control works on the principle of information from the outlet of a process being “fed back” to the input of that process for corrective action. A block diagram of feedback control looks like a loop: The reason any control system is necessary at all to...
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Ratio control

Most people  have likely had the experience of adjusting water temperature as they took a shower with dual valves: one valve controlling the flow of hot water and another valve controlling the flow of cold water. In order to adjust water temperature, the proportion of one valve opening...
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Supervisory control

In a manually-controlled process, a human operator directly actuates some form of final control element (usually a valve) to influence a process variable. Simple automatic (“regulatory”) control relieves human operators of the need to continually adjust final control elements by hand, replacing this task with the occasional adjustment...
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