HOME  |  NEWS  |  BLOGS  |  MESSAGES  |  FEATURES  |  VIDEOS  |  WEBINARS  |  INDUSTRIES  |  FOCUS ON FUNDAMENTALS
  |  REGISTER  |  LOGIN  |  HELP
Feature
Automation & Motion Control

Factory Automation Design & the AC-DC Equation

NO RATINGS
Page 1 / 2 Next >
View Comments: Threaded|Newest First|Oldest First
Rob Spiegel
User Rank
Blogger
AC or DC?
Rob Spiegel   12/5/2013 10:53:12 AM
NO RATINGS
Good article, David. You showed just how complex this question actually is.

William K.
User Rank
Platinum
The decision between motor types
William K.   12/6/2013 8:57:24 PM
NO RATINGS
This is an interesting post that does provide some useful insight. But the slant toward brushless low voltage motor controls is sort of obvious. So clearly the choice needs to be based at least partly on just exactly what the motor need to do. But other concerns include the cost of controls and the maintenance of those controls. A standard small three-phase motor can go for many years with no attention at all, and if something does eventually fail there are lots of folks qualified to do the repairs. Brushless motors are quite a bit more complex, and servicing their systems requires a good bit more skill and education.

So the choice is not always simple and straight-forward.

Cabe Atwell
User Rank
Blogger
Re: The decision between motor types
Cabe Atwell   1/20/2014 5:36:50 PM
NO RATINGS
Indeed, some factories require both AC and DC, which can further complicate matters.

William K.
User Rank
Platinum
Re: The decision between motor types
William K.   1/20/2014 8:54:22 PM
NO RATINGS
We have an interesting statement here, "AC motors must generate a magnetic field in order to operate. As a result, AC motors typically have high inrush currents." My experience is that ALL motors must generate a magnetic field to operate. Sort of an interesting argument. PM motors don't need to generate two magnetic fields, so they are a bit more efficient in that aspect. 

What is indeed certainis that some kinds of motors are easier to control than others, and some are much simpler to ramp up the speed with than others. But just running on a lower voltage actually reduces efficiency because the resistance losses are greater. The 24 volt DC motor is probably a lot simpler to use as an intermittant duty motor with the speed ramped up and down, and it is undoubtedly more efficient than an AC motor running constantly with a slip clutch slipping when things are halted. 

My point here is that the benefits come from the application of more complex control schemes, not because of some particular technology. Variable speed AC drives can also deliver some real savings. 

Partner Zone
Latest Analysis
From home enthusiasts to workers on the manufacturing floor, everyone's imagination is captured by the potential of 3D printing. Prototyping, spare parts creation, art delivery, human organ creation, and even mass product production are all being targeted as current and potential uses for the technology.
ABI Research, a firm based in the UK that specializes in analyzing global connectivity and other emerging technologies, estimates there will be 40.9 billion active wirelessly interconnected “things” by 2020. The driving force is the usual suspect: the Internet of Things.
Just in time for Earth Day, chemicals leader Bayer MaterialScience reported from the UTECH Europe 2015 polyurethane show on programs and applications using its materials to help reduce energy usage. The company also gave an update on its CO2-based PU as that eco-friendly material comes closer to production.
Solar and wind energy are becoming more viable as a source of energy on the electric grid. For decades, the major drawback to solar and wind was that they’re temperamental. A cloudy day kills solar and a still day renders the wind turbines useless. Automation tools, however, are providing a path to help these renewables become practical.
In honor of Earth Day, the National Security Agency has launched the STEM Recycling Challenge in Maryland schools to encourage kids to think about where the garbage they throw out every day actually goes. The agency has also introduced “Dunk,” a muscular blue cartoon recycling bin wearing shorts and sneakers.
More:Blogs|News
Design News Webinar Series
3/31/2015 11:00 a.m. California / 2:00 p.m. New York
2/25/2015 11:00 a.m. California / 2:00 p.m. New York
12/11/2014 8:00 a.m. California / 11:00 a.m. New York
5/7/2015 11:00 a.m. California / 2:00 p.m. New York
Quick Poll
The Continuing Education Center offers engineers an entirely new way to get the education they need to formulate next-generation solutions.
Apr 20 - 24, Taking the Internet of Things to the Cloud
SEMESTERS: 1  |  2  |  3  |  4  |  5  |  6 |  7


Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.
Last Archived Class
Sponsored by Proto Labs
Learn More   |   Login   |   Archived Classes
Twitter Feed
Design News Twitter Feed
Like Us on Facebook

Sponsored Content

Technology Marketplace

Copyright © 2015 UBM Canon, A UBM company, All rights reserved. Privacy Policy | Terms of Service