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Resolver & Synchro & LVDT

About Resolver

A resolver is an angle sensor that outputs rotational angles as two-phase AC voltages (analog signals). It features structurally high environmental resistance compared to other sensors due to its simple design comprised of only an iron core and a coil.
An AC output voltage is induced in the winding on the output side through excitation of the excitation winding using an AC voltage. As this output voltage will vary depending on the angle of rotation, the angle of rotation can be calculated using the voltage reading.


• Wide operating temperature range
• Excellent environmental resistance
• Rotatable at high speeds
• High reliability
• Absolute value position detection

• Long-distance transmission available (Highly resistant to noise)
• Compact assembly

Resolver System Structure



・BRX model (Amplitude-modulated)
Single-phase induced/two-phase output
・BRT model (Phase-modulated)
Two-phase induced/single-phase output
・BRS model (Amplitude-modulated)
Two-phase induced/two-phase output

Multiplication Factor for the Angle for the Resolver

The multiplication factor is defined to be 1x when an output signal for a single turn is generated when the resolver axis is turned once, 2x for an output signal generated for a double turn, and 4x for an output signal generated for a quadruple turn. In most cases, the angle detection accuracy increases as the size of the multiplication factor for the angle goes up.


The Singlsyn is an ultra-thin absolute angle detector. The VR series resolver has higher reliability and can be produced at lower cost as it does not have a coil on its rotor. Forming the rotor core into a special shape and changing the width of the gap between the rotor core and the stator core generates changes in the amplitude of the output voltage. The Singlsyn can be installed in a minimal amount of space due to the ultra-thin structure of the built-in model.


The Smartsyn is a built-in, brushless resolver designed using Tamagawa Seiki's unique and fully new winding system to produce a product that is low cost and high in productivity and has superior reliability and electrical characteristics. Resolvers formed using conventional winding systems could only be operated manually, but the resolvers produced using this new winding system can be set up to operate automatically using a coil winding machine.

SmartCoder (Resolver/Digital converter)

A resolver/digital converter, which is made up of a robot, a brushless motor controller or other type of controller, and a driver, which are in turn used as an interface for CPU digital processing, works to convert analog resolver signals into digital signals and is used in a wide range of applications.


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