Sensor methods
Custom designs
If you require a custom design, integrated into your application, we can provide:
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Coil designs matched to your application requirements and environment
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Optimized for size/tolerances/performance/cost
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Fast response
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Selection of low-cost high reliability ICs from a range of manufacturers
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Physical samples
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Support through to production
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Flexibility of manufacturing route – you can build in house, or subcontract using conventional PCB manufacturing and assembly.
Design process
If one of our existing samples is close to your requirements, we can often deliver a customized version quickly: whether that means adjusting the connector, pole pair count, PCB outline, or even switching the inductive sensing IC.
However, many applications require a fully custom design. This is often due to tight mechanical integration or the bespoke nature of the motor or end-use.
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The process begins with a collaborative discussion to understand your electrical and mechanical requirements, potential sensor locations, and integration constraints. In many cases, existing system components, such as a motor rotor, can be adapted as sensor targets, offering cost and space efficiencies. Each integration option has trade-offs in terms of coil design, performance, and ease of implementation.
Low cost, safe, high reliability inductive sensor ICs are available from automotive sensor IC suppliers. We can select one to meet your requirements or work with your chosen supplier.
Once the requirements are defined, we identify the optimal sensor architecture to meet performance targets across system tolerances. Our proprietary design and simulation tools allow us to efficiently create an inductive sensor design tailored to your application.
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After finalising the coil design, we typically can integrate supporting electronics and deliver working prototypes. Typically delivered within six weeks of specification agreement.
Production
In many cases, the design and documentation provided with your initial samples are all you need for production.
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If you already assemble PCBs in-house, the encoder can be integrated directly into your existing manufacturing process.
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Alternatively, a local EMS (Electronics Manufacturing Services) or CEM (Contract Electronics Manufacturer) partner can efficiently handle series production.
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The inductive sensor IC is readily available through the manufacturer or authorized distributors, giving you full control over key production factors such as location, standards, and cost.
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Sensor Methods can also support you through to production as needed: whether that involves IC programming, calibration, qualification or end-of-line testing. Our goal is to ensure a smooth transition from prototype to reliable, scalable production.
Supporting high volume automotive
We have a proven track record in high volume automotive developments. Our support is often structured to align with industry-standard development phases, such as RFI/RFQ, and A, B, and C sample stages​
Inductive sensor technology is now more accessible than ever for automotive suppliers integrating PCBs into their systems. Proprietary ASICs and restrictive patents have given way to standard inductive sensor interface ICs (ASSPs), developed in compliance with the ISO 26262 functional safety standard. When combined with expert coil design and support from Sensor Methods, these components form a robust, ASIL-rated sensing solution.
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Inductive sensor ICs fall into two main categories based on response time:
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Fast-response (microsecond) sensors – Ideal for high-speed applications such as rotor position sensing in electric vehicle traction motors.
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Slower-response (millisecond) sensors – Commonly used in rotary applications like pedals, chassis systems, and EGR valves, as well as linear applications in transmissions, gearboxes, rear-steer axles, and other drivetrain components.
As the demand for immunity to external magnetic fields increases, inductive technology is becoming the preferred choice for steering torque and angle sensing. Many of these applications also require redundancy to meet stringent safety and reliability standards.
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Achieving optimal performance across tolerance ranges while minimising costs requires careful design optimization and a solid understanding of PCB cost drivers. With Sensor Methods’ expertise, you can confidently meet these challenges and integrate high-performance, cost-effective sensing solutions into your automotive systems.
Inductive Position Sensor Design: Coil Design for Volume Applications
Designing an effective inductive position sensor for volume applications requires careful trade-offs, especially when minimizing sensor size is a priority. Compactness reduces cost and eases integration but it must be carefully balanced against several critical constraints.
These constraints include:
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Signal Integrity: The sensor must consistently detect a strong target signal across its full airgap tolerance range.
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Geometric robustness: Accuracy must be maintained despite mechanical and manufacturing tolerances.
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Transmit coil stability: The transmit (TX) coil must operate within IC specifications across the full temperature range and PCB manufacturing variations.
There are also design choices around the target:
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Target Style: Choose between solid metal or PCB-based targets, each offering different levels of complexity and performance.
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Material Selection: The selection of either conductive or ferromagnetic material directly impacts signal strength and influences the coil design.
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Target dimensions: The target interacts with the sensor coils and the dimensions of both the target and coils are optimized together.
The receive coil design options are also important: the style of the RX coil; the use of two coils (sine and cosine); or three (each 120° phase shifted).
Throughout the design low direct coupling (between the TX and RX coils) needs to be maintained along with low-cost PCB design rules.
Inductive coil design becomes more challenging in applications where more coils are added, for reasons such as redundancy, accuracy or capturing more complex movements. All the previous constraints apply with additional constraints around the interactions between the different measurement channels.