What is a resolver?
Resolver is the current domestic professional name, referred to as "rotating change". Because the basic principle of its work is the Transformer, the air gap of the "transformer" on the stator changes periodically during the work process by rotating the rotor, and then forms the function of monitoring the angular displacement (speed and position) of the motor rotor, so its full name is rotating transformer, which can also be translated into Rototary Transformer. However, this name is rarely used in English, and the general English name is Resolver.
A resolver is an electromagnetic device used to measure the angular position of a rotating shaft. It produces analog signals, typically sine and cosine waves, which can be processed to determine precise shaft angle and speed. Resolvers are reliable and widely used in industrial and automotive applications.
Why Choose Our Precision Resolvers?
Superior Reliability in Harsh Environments: Unlike optical encoders, our resolvers thrive under extreme temperatures, high humidity, vibration, and heavy shock, making them the gold standard for automotive and aerospace applications.
Immunity to EMI: The electromagnetic design offers natural resistance to electromagnetic interference (EMI), ensuring stable data transmission in electrically noisy environments.
100% MES Traceability: We implement a 100% full inspection production line. With our integrated MES (Manufacturing Execution System), every raw material and production process is fully traceable, guaranteeing zero-defect quality.
Advanced Customization: We offer strong R&D support to customize resolvers based on your specific motor design, control requirements, and housing constraints.
Core Applications of Resolvers
EV & Hybrid Powertrains: Critical for motor rotor position sensing in electric vehicles.
Industrial Robotics: Ensuring high-precision joint movement and repeatability.
Aerospace & Defense: High-reliability feedback for flight control actuators and radar systems.
Medical Equipment: Accurate positioning for CT scanners and surgical robotics.
Specifications of Resolvers
| Performance Parameters |
| Number of pole-pairs | 2X | 3X | 4X |
| Dimension (mm) | φ37;φ52;φ65;φ74;φ101 | φ37;φ52;φ65;φ74;φ101 | φ37;φ52;φ65;φ74;φ101 |
| Input voltage | AC7Vrms 10KHz | AC7Vrms 10KHz | AC7Vrms 10KHz |
| Transformer ratio | 0.286±10% | 0.286±10% | 0.286±10% |
| Temperature | -30°C ~ +150°C | -30°C ~ +150°C | -30°C ~ +150°C |
| Accuracy | ±60' | ±45' | ±30' |
| Phase shift | 0°±15° | 0°±15° | 0°±15° |
| Input impedance | 75Ω ~ 150Ω (Can be customized on demand) | 75Ω ~ 150Ω (Can be customized on demand) | 75Ω ~ 150Ω (Can be customized on demand) |
Resolver vs. Optical Encoder vs. Hall Sensor: Key Differences and Uses
| Item | Resolver | Optical Encoder | Hall Sensor |
| Operating Principle | Rotary transformer, generates analog signals | Optical sensing, converts position into digital signals | Hall effect sensing, detects magnetic field changes |
| Output Signal | Analog | Digital | Digital |
| Resolution & Accuracy | High accuracy, moderate resolution | Ultra-high resolution & accuracy | Low resolution & accuracy |
| Environmental Resistance | Extremely robust: high temp, shock, oil, dust, vibration | Sensitive to dust, high temp, impact, radiation | Moderate; sensitive to high temperature over time |
| Max Working Temp | Up to 150°C or higher | Typically ≤85°C | ≤85°C (performance degrades when heated long-term) |
| Reliability & Lifetime | Very high reliability, long service life | Medium, requires maintenance | Lower, limited lifetime due to thermal degradation |
| Installation & Integration | Needs decoding circuit, more complex | Direct digital output, easy integration | Simple, low-cost integration |
| Cost | High | Highest | Lowest |
| Main Advantages | Extreme environment resistant, high reliability, long life | High precision, high noise immunity | Low cost, simple structure |
| Main Disadvantages | Analog output, decoding complex | Poor durability in harsh environments | Low accuracy, short service life |
Future-Ready Technology
As industries move toward smart manufacturing, our resolvers are evolving with miniaturization, higher resolution, and IoT integration. We provide cost-effective, high-durability solutions that optimize energy output and reduce system downtime.
