Encoders & position sensors

Measures rotational or linear position for feedback. Motor-side and output-side measurements describe different parts of a joint.

How a magnetic encoder senses rotation

Rotate the two-pole magnet above a stationary sensor. Open the sensor package and follow shaft angle into an ideal digital reading.

Drag to rotate · pinch / scroll to zoom

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Magnet, sensor & angle output

The magnet rotates; the Hall sensor and circuit board stay still.

Ideal 14-bit code
0
Positions per turn
16,384

Ideal readout, not measured accuracy. The coloured halves mark opposite magnetic poles.

Source & model scope

Original Korthos illustration of on-axis magnetic sensing, using the AS5048A as the functional reference. Package internals, PCB traces, components, dimensions and spacing are illustrative; this is not the SpryDrive board or the chip’s recovered die layout. The 14-bit readout is an ideal angle-to-code mapping with zero offset. It does not predict sensor accuracy, noise or magnetic-field strength.

AS5048A technical reference · Illustration source · Model scope & reuse

Representative products

Component directory
Architecture, materials & specificationsArchitecture options, material requirements and integration constraints

Architecture options

ApproachMechanismAdvantagesTrade-offs
OpticalA detector reads a patterned scale.Supports fine position measurement without a magnetic target.Scale cleanliness, alignment and protection affect installed accuracy.
MagneticSensors read the field from a magnetic target.Works without a clear optical path.Target alignment and stray fields from nearby motors affect measurement.
InductiveConductive patterns couple electromagnetic signals across a gap.Can use compact PCB-based sensing without a permanent-magnet target.Target geometry, spacing and electronics determine accuracy.
CapacitivePatterned electrodes sense position through electric-field coupling.Offers another compact option without an optical scale or magnetic target.Installation tolerances and the sensing electronics still constrain performance.

Specifications & operating limits

Resolution is the smallest reported position step. Accuracy is closeness to the true position; repeatability is how consistently the same position is reported. More bits can give finer steps without improving installed accuracy.

Materials & constraints

Scale or target
Glass, metal or magnetic material depends on the sensing method.
Electronics
Photodetectors or sensing circuits convert position into a signal.
PCB conductors
Form sensing patterns in inductive designs.

Dependencies & engineering limits

Mounting & accuracy
An off-centre scale, tilted mounting or moving bearing axis adds position error. These installation errors affect accuracy independently of resolution.
Bearings
Assembly & verification
Installed alignment and signal quality can vary across the motion range. Calibrating predictable error can improve results, but it does not remove looseness or changing deformation.
Timing & control response
The controller needs the correct interface and timely readings. Transmission delay and inconsistent timing affect the feedback loop even when the measured position is accurate.
Compute & control
Sensor location & what is known
A motor-side encoder measures before the gearbox; an output-side encoder measures after it. Transmission play and twist can make those positions differ under load.
Strain-wave / harmonic reducers

Manufacturing & assembly

Guide

About this route

The route shows one process or architecture. Select a step to see its function and connections; related parts can be parallel inputs or alternatives.

Function

Inputs & dependencies
Outputs & connections
Related processes & parts
Sources

Manufacturing · Representative route. Scale manufacture and readhead installation lead to measurement of the completed axis.

Related parts & processes 4

Scale substrate

A glass or metal ring or disc carries the markings that encode angle. Another construction wraps a linear scale around a shaft.

Uneven spacing of the markings introduces angle-measurement error.

Sources & technical scope

Illustrative images of generic materials and components.

Link to this detail

Market context

KingKong humanoid-encoder market claim

>80%China humanoid encoders · July 2026 company claim

China-specific company claim; measurement period, denominator and unit-versus-revenue basis are not disclosed.

KingKong encoder production

300,0002025 output
2m2026 annual capacity target

Company-wide robotic encoders. The 2026 figure is planned capacity, not achieved output or deliveries.

Renishaw

Renishaw is expanding encoder production and redesigning some existing products around components in short supply. Its magnetic-encoder sales grew with industrial automation and robotics demand, while semiconductor demand drove optical-encoder growth.

Explore documented supply relationships →