In advanced servo products and servo drives, the resolver module serves as the cornerstone of precise motion control. Acting as an angle-dependent transformer, it converts…
In advanced servo products and servo drives, the resolver module serves as the cornerstone of precise motion control. Acting as an angle-dependent transformer, it converts the rotation of angle from a motor shaft into electrical signals that represent real-time position. These signals, after digital conversion, provide essential feedback for servo motors, ensuring smooth, synchronized movement across industrial machinery.
At Venus Automation, we supply durable resolver feedback modules and components engineered for heavy-duty applications. With models featuring IP67 rated protection, 304 stainless steel housings, and sealed bearings, our resolver solutions guarantee dependable operation even in high-temperature and high-vibration environments.
What Is a Resolver Module?
A resolver module is an electromechanical sensor that translates mechanical motion into corresponding electrical output. Often described as an analog encoder, it outputs sine and cosine signals that vary with shaft rotation. These are processed by an RDC (Resolver-to-Digital Converter) to generate a digital value representing the shaft’s angular position.
Resolvers are widely used in brushless resolvers and servo motor systems because they offer greater temperature resistance and longer life than optical encoders. Common industrial examples include the Smartsyn Resolver Module, AMCI Resolver, and Hengstler R25 Series Resolver, all known for their precision in field-oriented current control.
Why Resolver Feedback Matters
High-Temperature Performance
Unlike optical encoders, resolver modules tolerate high temperatures up to 155°C and beyond. Their rugged housing and anodized aluminum housings make them ideal for industrial motor connections exposed to dust, oil, and vibration.
Electrical Robustness
Resolvers function without direct electrical contact, providing inherent electrical isolation and immunity to EMI. This design ensures signal integrity across long cable distances, especially when paired with INTERCONTEC connectors or mag-mate terminals for quick installation.
Longevity and Strength
A resolver module’s stainless steel shaft and sealed bearings deliver superior mechanical durability, supporting extended lifecycles in servo drive and motor brake applications. Whether integrated into new equipment or used as a retrofit part, resolver modules deliver unmatched reliability.
How Resolver Modules Work
The resolver operates as a rotary transformer with one rotor winding and two stator windings arranged at 90 degrees. When excited by an AC reference voltage, the output signals follow sine distribution and cosine laws, representing angular displacement. A resolver interface circuit or digital conversion module (RDC) processes these analog waveforms into absolute angle data.
This feedback is sent to the servo drive, which adjusts current, torque, and position through PI speed control or CONTROL TECHNIQUES such as field-oriented current regulation. The process creates a closed-loop feedback system, improving positioning accuracy and stability.
Construction and Materials
High-performance resolver modules use 304 stainless steel housing, anodized aluminum housings, and corrosion-resistant coatings for long service life. Their DIN-rail or PC bus mounting options make installation straightforward.
Manufacturers such as TE Connectivity, Red Lion Controls, and NIDEC CORP offer resolver assemblies and electronic components optimized for industrial supplies and mechanical components markets.
Resolvers designed for heavy-duty applications—like the AMCI H25 Resolver Transducer, AMCI HT-20 Single-Turn Transducer, and Tamagawa TS2651N181E78—provide rugged reliability in sectors requiring precision under stress.
Resolver Feedback in Servo Motors
Integration and Operation
When paired with servo drives such as UniDrive 2403 or AB 1394 amps, the resolver’s feedback loop ensures that servo motors maintain correct phase alignment, position control, and torque response. The result is high-speed synchronization and zero loss of step even under variable load.
Resolvers also support hybrid configurations featuring Encoder Output or secondary feedback channels. These allow absolute angle data to coexist with incremental encoder systems for enhanced redundancy.
Control and Conversion
Resolvers work in tandem with EtherCAT Terminals, power semiconductors, and DC link circuits to form a compact feedback and control loop. This integration provides precise speed and torque control essential for compact drive technology and permanent magnet-excited three-phase synchronous motors.
Environmental and Mechanical Protection
Industrial environments often expose equipment to oil, dust, or moisture. Resolver modules designed for IP67 rated protection withstand these elements while maintaining calibration accuracy. Their Rugged housing, sealed bearings, and stainless steel shafts ensure performance longevity.
For applications demanding additional resilience, Anodized aluminum housings provide excellent thermal conductivity and corrosion protection, making them suitable for machine parts and electrical control cabinets.
Resolver Module Examples and Compatibility
Popular industrial resolver models include:
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Smartsyn Resolver Module – Part Number 5011000
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Hengstler R25 Series Resolver
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Tamagawa TS2651N181E78
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AMCI H25 Resolver Transducer
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AMCI HT-20 Single-Turn Transducer
These models integrate seamlessly with major brands such as Schneider Electric, TE Connectivity, and NIDEC CORP, providing compatibility across leading servo products and electronic components used in automation.
Applications in Heavy-Duty Industries
Resolver modules are found across sectors requiring high-accuracy, noise-immune feedback:
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Motors & Motor Control Systems
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Robotics and Motion Platforms
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Aerospace Actuators
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CNC Machine Tools
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Material Handling Equipment
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Industrial Automation Lines
From IP67-rated environments to high-temperature furnaces, these sensors deliver stability where optical encoders struggle. Combined with power contacts, circuit breakers, and proper INTERCONTEC connectors, they create reliable feedback networks for industrial motion.
Support and Product Availability
Venus Automation provides an extensive catalogue of resolver modules, servo drives, and electronic components sourced from global leaders such as TE Connectivity and Schneider Electric. Our sales team assists with sales enquiries, part compatibility, and support resources, ensuring customers find the right products quickly.
We also stock legacy and obsolete resolver modules with Radwell Warranty coverage and detailed Product Selector data for accurate Part Number matching. Contact our team today for pricing, stock status, and technical documentation.
