HOME  |  NEWS  |  BLOGS  |  MESSAGES  |  FEATURES  |  VIDEOS  |  WEBINARS  |  INDUSTRIES  |  FOCUS ON FUNDAMENTALS
REGISTER   |   LOGIN   |   HELP
Blogs
Mechatronics Zone
Even More on Rotary Encoders
3/5/2013

This diagram shows the carrier signal and the modulation by a sine and cosine signal. The vertical line indicates sampling at signal maxima. Note the phase change in the sine signal at 0 and 180 degrees, and in the cosine signal at 90 and 270 degrees.
This diagram shows the carrier signal and the modulation by a sine and cosine signal. The vertical line indicates sampling at signal maxima. Note the phase change in the sine signal at 0 and 180 degrees, and in the cosine signal at 90 and 270 degrees.

Return to Article

View Comments: Newest First|Oldest First|Threaded View
Jack Rupert, PE
User Rank
Platinum
Thanks!
Jack Rupert, PE   3/22/2013 5:01:11 PM
NO RATINGS
Thanks for the series.  I'm hanging on to the links so that the new people can get some training on stuff that isn't taught in the schools.

ttemple
User Rank
Platinum
sin-cos excitation
ttemple   3/5/2013 8:58:40 AM
NO RATINGS
Jon,

In the old days, it was common to excite the sin and cos windings with sinusoidal signals that were 90 degrees out of phase (sin and cos).  Then when the shaft rotates, the rotor winding produces a fixed amplitude sine wave, whose phase shifts in proportion to the shaft angle.  The control system must then resolve the phase angle of the rotor winding against a reference wave.  This was a relatively easy thing to do with analog circuitry.  The reference waveform could be the position command signal.  The command signal to the actuator is then proportional to the phase error between the resolver rotor and the reference signal.

Partner Zone
More Blogs from Mechatronics Zone
Suppose you wanted to create a FIR filter with your own requirements. How would you find the necessary coefficients, and how many of them would you need?
Switched-capacitor filters have a few disadvantages. They exhibit greater sensitivity to noise than their op-amp-based filter siblings, and they have low-amplitude clock-signal artifacts -- clock feedthrough -- on their outputs.
Engineers use rotary encoders to measure the angular position of an attached device or to measure distance indirectly.
The Machinist Calc Pro computes speeds and feed rates for milling, turning, and drilling: cutting speed, spindle speed, feed rate (inches/minute), cutting feed, etc.
Design News Webinar Series
3/27/2014 11:00 a.m. California / 2:00 p.m. New York / 7:00 p.m. London
2/27/2014 11:00 a.m. California / 2:00 p.m. New York / 7:00 p.m. London
12/18/2013 Available On Demand
11/20/2013 Available On Demand
Quick Poll
The Continuing Education Center offers engineers an entirely new way to get the education they need to formulate next-generation solutions.
Apr 21 - 25, Creating & Testing Your First RTOS Application Using MQX
SEMESTERS: 1  |  2  |  3  |  4  |  5


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.
Next Class: April 29 - Day 1
Sponsored by maxon precision motors
Learn More   |   Login   |   Archived Classes
Twitter Feed
Design News Twitter Feed
Like Us on Facebook

Sponsored Content

Technology Marketplace

Datasheets.com Parts Search

185 million searchable parts
(please enter a part number or hit search to begin)
Copyright © 2014 UBM Canon, A UBM company, All rights reserved. Privacy Policy | Terms of Service