| Feature | Synchro (Moog Type 11TX) | Resolver (Moog Type 15RX) | | :--- | :--- | :--- | | | 3-wire (120° phase separation) | 2-wire (Quadrature: Sine/Cosine) | | Typical Interface | Scott-T transformer or Synchro-to-Digital | Resolver-to-Digital Converter (RDC) | | Best For | Legacy analog systems, torque repeaters | Modern digital servo loops, robotics | | Range | 0° to 360° (Absolute) | 0° to 360° (Absolute) | | Failure Mode | Loss of one phase distorts angle | Loss of Sine or Cosine breaks tracking | | Moog Recommendation | Retrofit/Aircraft indicators | New designs, high-speed axis |
Why? Because the predicted the limits of optical sensing. As motors spin faster (20,000+ RPM), encoders suffer from bandwidth limitations. A resolver is analog; it has no quantization noise except for the RDC. The handbook’s chapter on "Bandwidth Limitations" explains that a resolver’s only delay is the inductive time constant (L/R)—measured in microseconds, not milliseconds. Synchro And Resolver Engineering Handbook Moog Inc
The handbook is structured to move from fundamental operational theory to advanced integration strategies, ensuring it remains relevant for both new students and seasoned professionals. | Feature | Synchro (Moog Type 11TX) |
The resolver is its more refined sibling, using two output windings (sine and cosine) rather than three. This makes it mathematically purer and, therefore, the darling of aerospace and defense applications. A resolver is analog; it has no quantization
Moog utilizes specialized winding machines that control the copper placement to sub-micron tolerances. The handbook explains that "orthocyclic winding" (layers of wire packed in perfect hexagonal close-packing) reduces the "harmonic content" of the output signal. Less harmonic distortion means higher accuracy for the RDC.
While the theory is universal, this section ties it to Moog’s actual manufacturing. It covers: