In modern industrial automation, automotive electronics, and intelligent equipment fields, dual-channel sensors are highly favored for their ability to provide redundant, reliable, and high-precision position feedback. These sensors typically integrate two independent signal channels, imposing stringent requirements on the performance consistency, long-term stability, and adaptability to complex environments of their core magnetic components. Leveraging the expertise of its core team with over two decades of experience in magnetic materials, Ningbo Buoy Magnetoelectric Technology Co., Ltd. has developed a targeted solution based on high-performance bonded magnet components to address this need.

I. Core Requirements of Dual-Channel Sensors and Advantages of Bonded Magnet Components

      Dual-channel sensors are widely used in critical detection scenarios such as steering angle, throttle position, and high-performance motor commutation. Their core requirement is to ensure that the output signals from the two sensing channels possess high degrees of synchrony, linearity, and long-term stability. Any signal deviation caused by inconsistent performance or degradation of the magnetic components can compromise the overall system reliability and control accuracy.

      Traditional magnetic component solutions may face challenges in such applications, including cumulative tolerances from multi-part assembly, magnetic performance fluctuations due to temperature changes, and potential signal drift over long-term use. The bonded magnet component solution provided by Ningbo Buoy Magnetoelectric demonstrates distinct advantages:

      Excellent Consistency: The precision injection molding process enables the single-step manufacture of bonded magnetic elements with complex structures and precise dimensions. This process ensures extremely high dimensional and shape consistency across production batches, providing a foundation for the two independent channels to receive matching magnetic field sources.

      Design Integration and Freedom: Bonded magnet technology allows for the integration of multi-pole magnet rings, specific magnetic circuit structures, and mounting features into a single molded part. Engineers can optimize magnetic pole shape and distribution to achieve more ideal and linear sinusoidal/cosine magnetic field signals at the sensor chip, directly enhancing detection accuracy and reliability.

      Outstanding Environmental Stability:Bonded magnet components using high-performance engineering plastics like PPS (polyphenylene sulfide) or PA (nylon) as binders offer excellent heat resistance, chemical corrosion resistance, and mechanical strength. This ensures stable magnetic output performance under harsh conditions such as high temperature, oil contamination, and vibration, effectively minimizing sensor temperature drift.

II. Specific Solution: Technological Implementation from Material to Component

Ningbo Buoy Magnetoelectric's solution encompasses the entire process from material selection and structural design to manufacturing:

      Precise Material System Matching: The company provides bonded magnet materials based on either NdFeB (neodymium iron boron) or Ferrite, tailored to the magnetic performance requirements and cost considerations of different applications. NdFeB bonded magnets offer higher magnetic energy product, suitable for scenarios demanding high signal strength or miniaturization, while Ferrite bonded magnets are advantageous for cost-sensitive applications with high corrosion resistance needs.

      Precision Multi-Pole Magnetization Technology:Dual-channel sensors typically require multi-pole-pair magnet rings. A core competency of the company is achieving high-precision, high-consistency multi-pole magnetization. Through precise magnetization tooling and process control, it ensures clear magnetic pole boundaries, accurate positioning, and uniform magnetic flux distribution—the physical prerequisite for generating high-quality dual-path differential signals (e.g., Sin/Cos).

      Componentized Integrated Supply:Beyond standard bonded magnet rings, the company supplies customized magnetic assemblies integrated with bearings, bushings, or protective structures according to customer requirements. This componentized approach simplifies customer assembly, reduces overall system assembly errors, and improves product yield.

III. Case Study: Application in an Automotive Electric Power Steering (EPS) Angle Sensor

1. Project Background and Challenge:

      A Tier-1 automotive supplier faced challenges developing a dual-channel absolute position sensor for a new-generation Electric Power Steering (EPS) system. The sensor needed to operate across a full temperature range of -40°C to 150°C, ensuring highly consistent absolute angle outputs from both channels, with lifetime angle error controlled within a stringent limit. Previously tested magnetic components exhibited batch-to-batch performance variation and signal attenuation at high temperatures.

2. Ningbo Buoy Magnetoelectric's Solution:

      Customized Design:Developed a thin-walled, multi-pole (e.g., 32 pole-pairs) ring-shaped bonded magnet assembly based on the sensor chip's sensitivity characteristics and installation space constraints.

      Material Selection:Recommended PPS-bonded NdFeB material for its outstanding high-temperature resistance, ensuring magnetic performance stability in the high-temperature environment near the engine compartment.

      Process Guarantee: Employed precision injection molding and magnetization technology to guarantee pole angle accuracy and magnetic flux consistency for each magnet ring, supported by 100% online inspection and sorting.

3. Application Results:

      With the customized bonded magnet assembly, the customer's dual-channel sensor met all target performance indicators. The output signals from both channels demonstrated excellent consistency and linearity across the entire temperature range, satisfying the functional safety requirements for ASIL D. The integrated assembly design also simplified the sensor module assembly process, enhancing production efficiency and product reliability. This successful collaboration reinforced Ningbo Buoy Magnetoelectric's position as a professional and reliable magnetic solution provider.

IV. Summary and Outlook

      In high-stakes applications like dual-channel sensors, where precision and dependability are non-negotiable, the performance of the magnetic components is vital. Ningbo Buoy Magnetoelectric Technology Co., Ltd.'s bonded magnet component solution—characterized by its high consistency, stability, design flexibility, and integrated supply—effectively fulfills the sophisticated technical demands of advanced sensing.

      As industrial and automotive automation continues to evolve, driving ever-higher requirements for sensor precision and functional safety, Ningbo Buoy Magnetoelectric will continue to leverage its profound technical expertise. The company remains dedicated to delivering high-performance, cost-optimized magnetic application solutions, collaborating with industry partners to advance sensing technology and foster innovation.