Anatech Electronics (RF Filters) - RF Cafe
LadyBug Technologies LB5944A RF Power Sensor - RF Cafe

About RF Cafe

Kirt Blattenberger - RF Cafe Webmaster

Copyright: 1996 - 2024
    Kirt Blattenberger,


RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The World Wide Web (Internet) was largely an unknown entity at the time and bandwidth was a scarce commodity. Dial-up modems blazed along at 14.4 kbps while tying up your telephone line, and a nice lady's voice announced "You've Got Mail" when a new message arrived...

All trademarks, copyrights, patents, and other rights of ownership to images and text used on the RF Cafe website are hereby acknowledged.

My Hobby Website:

Electronics World articles Popular Electronics articles QST articles Radio & TV News articles Radio-Craft articles Radio-Electronics articles Short Wave Craft articles Wireless World articles Google Search of RF Cafe website Sitemap Electronics Equations Mathematics Equations Equations physics Manufacturers & distributors Engineer Jobs LinkedIn Crosswords Engineering Humor Kirt's Cogitations RF Engineering Quizzes Notable Quotes App Notes Calculators Education Engineering magazine articles Engineering software Engineering smorgasbord RF Cafe Archives RF Cascade Workbook 2018 RF Symbols for Visio - Word Advertising RF Cafe Homepage Thank you for visiting RF Cafe!
Anatech Electronics

Phase Method of Resolver Decoding - RF Cafe Forums

RF Cafe Forums closed its virtual doors in 2012 mainly due to other social media platforms dominating public commenting venues. RF Cafe Forums began sometime around August of 2003 and was quite well-attended for many years. By 2010, Facebook and Twitter were overwhelmingly dominating online personal interaction, and RF Cafe Forums activity dropped off precipitously. If the folks at phpBB would release a version with integrated sign-in from the major social media platforms, I would resurrect the RF Cafe Forums, but until then it is probably not worth the effort. Regardless, there are still lots of great posts in the archive that ware worth looking at.

Below are the old forum threads, including responses to the original posts.

-- Amateur Radio
-- Anecdotes, Gripes & Humor
-- Antennas
-- CAE, CAD, & Software
-- Circuits & Components
-- Employment & Interviews
-- Miscellany
-- Swap Shop
-- Systems
-- Test & Measurement
-- Webmaster

Post subject: Phase Method of Resolver Decoding
Unread post Posted: Thu Mar 03, 2005 3:18 pm


Looking for any information on circuits that will decode analog resolver signals into unambiguous binary positional data.

I'm specifically looking for information on a technique called the PHASE METHOD of decoding, wherein the sin & cosine windings are driven and the position data is extracted from the rotor signal. The rotor phase, relative to the reference signal phase, is compared to determine the amount of shaft rotation. The phases are compared by keeping track of their zero crossings, and a binary count output that represents their phase difference, (zero crossings) is generated. The binary output is generated by utilizing zero crossing detectors on the reference signal to start a binary up/down counter and alternately, zero crossings from the rotor signal are used to latch the binary count when they occur, the count that is latched by the rotor's zero crossing represents the difference in phase between the two signals and thus the amount of angular rotation of the shaft in binary. For example, a zero count, would mean the two signals are in phase, a 1/2 max count, signals are 180 out of phase, and so on. One must also keep track of rotation direction so the counter can count up or down in coordination with the direction. This system is not as complicated as it might first seem but I am looking for help from anyone who has experience with this technique.

I am specifically NOT looking for information on ratiometric tracking converters that typically drive the resolver's rotor and decode the sine and cosine signals. But rather, only information on this alternate PHASE METHOD.

Any info on this subject is wanted, explanations, insights, schematics, IC's, etc.


D. Rennie

(I apologize if this is the wrong forum for this post. Please point me to the correct one.)

Posted  11/12/2012
Copper Mountain Technologies - RF Cafe
ConductRF Precision RF VNA Test Cables - RF Cafe
LOTUS Communications Systems Modular RF Component Building Blocks - RF Cafe

Please Support RF Cafe by purchasing my  ridiculously low−priced products, all of which I created.

These Are Available for Free