Resolver: How does it work?
Most general-purpose position sensors used for Aircrafts

01. Basic Structure

Most general-purpose position sensors for Aircraft systems

The parts affect the sensing functions of Resolvers are composed of two different sections: one is Transformer Section (Stator Trans & Rotor Trans) and the other is Core Section (Stator Core & Rotor Core). Both sections have each coil in place.

Resolvers for Aircrafts eliminate brushes and transfer Alternating Current (AC) voltage between the coils. This structure enables contactless detection of angular information.

The greater parts of Resolvers are consist of metallic parts, such as Ball Bearing. This is the key thing that makes Resolvers robust. Resolvers are the most general-purpose position sensors used for Aircraft systems which requires Long Life, High Reliability and Environmental Resistance.

Electromagnetic induction

Resolvers have 6 lead wires, two for input and four for output.

02. Full Angle Detection

360 deg. “FULL ANGLE” Detection

The two-phase voltages fluctuate in response to the shaft rotation of Aircraft systems. For sensing purpose, these voltages can be converted to electrical angle. The combination of Rotor Core, Stator Core and optimized coil pattern enables smooth output characteristics.

Resolvers can fit for various kinds of Aircraft systems with their different types of speed specifications. For example, 1X-BRX Resolver can generate 1 cycle output characteristics by a shaft rotation, and 4X-BRX Resolver can generate 4 cycle output characteristics.

This output characteristics enables Resolvers to generate signals continuously even if the shaft rotates more than once. Therefore, Resolvers can realize 360 degree full angle detection responding to shaft rotation of Aircraft systems.

03. High Accuracy

Fit to wide variety of applications

Tamagawa Resolvers have their roots in Synchro, which was started development / production at Tamagawa 80 years ago. In the present day, various kinds of Tamagawa Resolvers are installed in both Commercial Aircrafts and Business Jets. Over this long period of history, Tamagawa gains the ability to produce Resolvers with the Accuracy ±10 minutes (±0.17 deg) and has a great deal of confidence in the technologies.

Column: R/D (Resolver / Digital) Converter

Resolvers generate two-phase output voltages as Analog Signal. R/D Converter is necessary for converting this Analog Signal into Digital Signal, and calculating electrical angular information.

Converter is usually installed inside Aircraft with stable environment. On the other hand, Resolver can be installed exposed exteriors of Aircrafts for position detection and transfer electrical signals via cable to Converter inside Aircrafts. For example, pilots receive position information in Cockpit via this Resolver measurement system.

04. Production

Automatic Winding Technology

Tamagawa has several production lines in Japan and abroad. Tamagawa’s own production engineering automates the winding process in accordance with Resolver designs. This automatic winding technology is one of Tamagawa's key technologies and this enables stable and high quality.