No Copy


No Right Click

Wednesday, April 15, 2009

Know How: General Knowledge

Electronic starters and variable speed drives

Summary

The most common way of starting asynchronous motors is directly on the
line supply. This technique is often suitable for a wide variety of machines.
However, it sometimes brings with it restrictions that can be inconvenient
for some applications, and even incompatible with the functions required
from the machine:
- The inrush current on start-up can interfere with the operation of other
devices connected on the same line supply
- Mechanical shocks during starting that cannot be tolerated by the
machine or may endanger the comfort and safety ofusers
- Acceleration and deceleration cannot be controlled
- Speed cannot be controlled
Starters and variable speed drives are able to counter these problems.
Electronic technology has made them more flexible and has extended their
field of application. However, it is still important to make the right choice.
The purpose of this "Cahier Technique" is to provide more extensive
information about these devices in order to make it easier to define them
when designing equipment or when improving or even replacing a motor
switchgear assembly for control and protection.

Reference

  • - Author :Daniel ClĂ©net
  • - Publication date:01/11/2003
  • - Page number:28
  • - ECT no:208

Data acquisition: Detection

Summary

In an automated installation, all the information needed to control it must be detected in order to be managed by the control systems.
The "detection" function is therefore essential in all industrial processes, and a knowledge of the various techniques is vital to choose the right detectors: they have to be able to operate in sometimes difficult environments and supply information that is compatible with the acquisition and processing systems.
This document is aimed at those wanting to familiarize themselves with the field of Detection in Industrial Automation.
After setting out the broad technical background to this field, each technology is analyzed in detail to provide a basic selection guide. This is complemented by an overview of related technologies, including Vision and RFID (Radio Frequency IDentification).
Detection may seem complicated at first, but you will soon learn that it is simply "varied"!
Happy reading!

Reference

  • - Author :Philippe Hampikian and his team
  • - Publication date:01/09/2005
  • - Page number:40
  • - ECT no:209

0 Comments:

#