This is the story of that handbook, the technology it champions, and why, in an age of digital abundance, its principles remain utterly indispensable. To understand the handbook, one must first understand the components at its heart. A synchro is, in essence, a rotary transformer. It looks like a small, precision motor but behaves like an analog computer. When you rotate its rotor, it outputs a set of three voltages (or receives them) that encode the exact angular position of a shaft. No glass disks, no LEDs, no fragile optics—just copper windings and a magnetic field.
For over half a century, this handbook has been more than a product catalog. It is a Rosetta Stone for translating the physical world of rotating machinery into the precise, unforgiving language of electronic feedback. Before optical encoders became cheap and ubiquitous, before Hall-effect sensors saturated the market, the synchro and the resolver were the undisputed kings of angular measurement. And Moog Inc.—a company more famous for its hydraulics on fighter jets and amusement park rides—wrote the definitive text on how to wield them. Synchro And Resolver Engineering Handbook Moog Inc
In a conference room in East Aurora, New York (Moog’s global headquarters), there is probably a worn copy on a shelf. And somewhere right now, an engineer is opening a PDF of that same handbook. They are trying to figure out why their resolver’s sine-cosine mismatch is 0.5% at 25°C but 1.2% at 85°C. They will find the answer in a footnote on page 4-17. And they will be grateful. This is the story of that handbook, the
The handbook was Moog’s bid to standardize the industry. Before it, every defense contractor had their own way of testing, specifying, and wiring these components. Noise margins varied wildly, compensation networks were treated as dark arts, and a resolver from one vendor might not talk to a servo amp from another. Moog’s engineers, led by a cadre of analog gurus whose names are now lost to corporate history, sat down and wrote the canonical text. It looks like a small, precision motor but
Because in motion control, as in life, the angle is everything. And nobody ever explained the angle better than Moog. This feature is a tribute to the technical writers, applications engineers, and analog designers at Moog Inc. who created and maintained the Synchro and Resolver Engineering Handbook—a work that continues to turn up on desks from Cape Canaveral to Shenzhen.
The handbook, in its quiet way, predicted this. Its chapters on “Environmental Performance” and “Reliability Under Vibration” were not theoretical. They were the product of Moog’s own test labs—shaker tables, thermal chambers, and life-cycle test rigs running for years. Today, you can download the Moog handbook (now often integrated into their broader “Motion Control” technical documentation). A fresh engineering graduate might look at it and ask: Why learn this? My servo drive auto-tunes. My FPGA handles the R/D conversion in a few microseconds.