IncOder™ Inductive Angle Encoders

IncOders work in a similar way to brushless resolvers and rotary variable transformers.  The IncOder Stator receives a DC power source and produces a low power AC electromagnetic field between the Stator & Rotor. This field is modified as the Rotor rotates.  The field is sensed by the Stator and the rotation angle output as an analogue or digital signal.  Unlike resolvers, IncOders use laminar circuits rather than wound wire spools. The patented technology enables IncOder’s compact form, low mass, low inertia and high accuracy without high precision installation.

Yes. Measurements will be the same before and after power interruption. No motion is needed at start up.

Yes. If BIT shows an internal error then an error signal is generated. The BITs include continuity/damage, presence of Rotor, in-range Rotor, gross electromagnetic malfunction, window watchdog timer, power on reset, power brownout reset, timeouts for clock input, read/write and internal flash data memory value checks.

Measurement performance is unaffected by humidity, condensation, dirt, dust, oil, mud or sand. All IncOders will survive temporary immersion to depths of 1m in salt or fresh water. Where frequent exposure to liquids, or immersion, is part of the operating environment, units with connections type AFL or VFL should be used.

No. Magnets produce DC fields.  IncOder’s operation is based on the detection of AC electro-magnetic fields at a highly specific frequency.

Use this document as a basis and specify any differences. Preferably, a standard outer diameter ‘A’ dimension (i.e. 37, 58, 75, 100, 125 mm etc.) and a proportionate inner diameter should be used. This enables us to use regular sensor components with analternative mechanical format.

Resolution, repeatability & accuracy (linearity) will be as specified, provided Rotor concentricity is within specified limits. One might expect accuracy to degrade significantly with concentricity, but IncOders use the full faces of Rotor & Stator, so errors are nulled by diametrically opposing factors. This is different to other encoder technologies – notably optical or capacitive devices – where performance depends on tightly controlled concentricity.

Yes. Many IncOders are used near powerful sources of electromagnetic noise such as motors or transformers. IncOder’s aluminium housing produces a Faraday cage effect around the internal electronics and the technology is designed so that incoming, far-field radiation is self cancelling or filtered out.

Operating temperature limits are set by some of IncOder’s electronic parts rather than the basic technique. Standard IncOders are rated -40 or 85oC operation and with a cold option (Product Options 12VCT & 24VCT) for -60oC operation. IncOders can be used outside these limits following qualification by the user. At temperatures >85oC the duration of any elevated temperature should be minimized. At temperatures at or below the stated lower limit, it is recommended to leave the unit powered or allow an extended powered period (>1 minute) before operation.

Yes. Use AFL or VFL cable connections or provide a mechanical seal around the connector. Some AFL or VFL connections are rated for submersion at <100m, however, some applications are successfully using such devices for prolonged submersion in water or mineral oil at >100m depth, without modification. If application requirements are for prolonged and>100m submersion, this should be qualified by the user. Contact us for further information.

Not usually. IncOders are exempt from Annex I to Council Regulation (EC) No. 428/2009, as amended [EU Dual-Use List] and only require an export license if the diameter is greater than or equal to 1000mm or accuracy is <1arc-second. No standard products are in this class.

Calibration is only relevant for some ultra high accuracy applications such as astronomical telescopes. Readings from an IncOder are stored and compared to a reference in a look-up table in the host system. Such an arrangement will negate any inaccuracy due to inherent non-linearity or installation tolerances. Resolution & repeatability are unaffected by calibration.