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Inductive encoder

LTN frameless resolvers inductive encoder

Brushless frameless (kit) resolvers in 36.83, 50.77 and 71.02 mm outside diameters with 1 to 5 pole pairs, 6 to 10 arcmin accuracy, up to 20,000 rpm and -55 to +155 °C, now produced and sold by HEIDENHAIN.

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Need LTN Servotechnik parts, a replacement or another suitable option? Send your part number or describe what the machine needs to do. We connect your requirement with experienced UK engineering and procurement support to help you get the right products, pricing and supply options. Your matched provider can take the enquiry through quotation and ordering to delivery and after-sales support.

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Specify what you need instead of LTN frameless resolvers

Select the products and performance you need. Our UK engineering team can use your specification to help source the right components, pricing and supply options. See your summary before adding contact details.

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  2. 2Performance
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What are you specifying?

Select everything you need. A motor, drive and gearbox can be specified together as one axis.

1 selected: Encoder

Key specifications

Outer diameter36.83–71.02 mm
Temperature-55–155 °C
Speed (max)20,000 rpm
Accuracy6 to 10 arcmin
Pole pairs1 to 5
Principlebrushless resolver, inductive signal transfer

Summarised in our own words from HEIDENHAIN Corporate Group (LTN brand; LTN Servotechnik GmbH ceased operations 30 April 2026)'s published data; series maxima, individual models vary. Last checked 2026-10-30. Source 1 · Source 2

Notes on this data

Resolvers classed under 'inductive' as the closest allowed encoder type. LTN Servotechnik GmbH ceased operations on 30 April 2026; HEIDENHAIN continues LTN resolvers.

Specify Motion is not affiliated with HEIDENHAIN Corporate Group (LTN brand; LTN Servotechnik GmbH ceased operations 30 April 2026). LTN Servotechnik and LTN frameless resolvers are used only to identify the product. Comparisons use published figures; always confirm against the current datasheet.

LTN frameless resolvers replacement and alternative options

Use these supply-network options as a starting point for an engineering check. We can also help source the original LTN Servotechnik part. Published series figures do not establish an exact-model or drop-in replacement: confirm ratings, fit, interfaces and approvals for your application.

Same product type; specifications need checking

Larger-bore Zettlex inductive absolute encoder from 75 to 300 mm OD with up to 22-bit resolution.

Same product type; specifications need checking

Celera Motion (Zettlex) non-contact inductive absolute angle encoder in 37 and 58 mm sizes, sealed to IP67, -60 to +105 C.

Figures are the highest published for each series and are not always measured the same way. A higher figure is not automatically a better choice: mounting, duty cycle, feedback, connectors and approvals matter too. An engineer will check the fit against your application before recommending anything.

Typical applications

Servo motor commutation and feedbackMachine toolsIndustrial robotsHarsh-environment drives

What an inductive encoder is

An inductive encoder measures position using coils printed on circuit boards: a transmitter coil creates an alternating magnetic field, and receiver coils pick up how a conductive target or rotor pattern modifies it as it moves. Electronics convert the signals into absolute position. With no optics, magnets or contacting parts, inductive encoders are highly tolerant of dirt, water, oil, shock and temperature. They are typically non-contact, bearingless and available in ring formats with large bores.

When engineers choose an inductive encoder

Choose an inductive encoder for harsh environments where optical encoders would be blinded and magnetic encoders could be disturbed, such as defence, aerospace, oil and gas, subsea and heavy mobile machinery. Large-bore rings suit gimbals and turrets. The trade-offs are resolution and cost: inductive encoders are typically less finely resolving than high-end optical encoders and may cost more than magnetic ones. Mounting is tolerant but still needs control.

How to specify the LTN frameless resolvers

Send these with your enquiry and an engineer can confirm the right LTN frameless resolvers variant or an equivalent:

  • Absolute resolution (bits)
  • Accuracy (arcmin or arcsec)
  • Outer diameter and bore (mm)
  • Interface: SSI, BiSS or analogue
  • Temperature range (°C)
  • Shock and vibration requirements (g)
  • Sealing and IP code

Common mistakes to avoid

  • Mounting conductive parts too close to the sensing area
  • Ignoring the encoder's permitted gap and alignment tolerances
  • Expecting top optical resolution
  • Overlooking EMC near high-power cables

LTN frameless resolvers: frequently asked questions

Can you help replace LTN frameless resolvers or source the original?

Send the full model code, quantity and required date. Our engineers can check original-part availability and assess suitable alternatives, including supply-network options where appropriate. We confirm compatibility and any changes needed before recommending a replacement.

What is the LTN frameless resolvers?

Brushless frameless (kit) resolvers in 36.83, 50.77 and 71.02 mm outside diameters with 1 to 5 pole pairs, 6 to 10 arcmin accuracy, up to 20,000 rpm and -55 to +155 °C, now produced and sold by HEIDENHAIN. Published series figures include outer diameter 36.83 mm, outer diameter 71.02 mm, temperature -55 °C, temperature 155 °C. It is made by HEIDENHAIN Corporate Group (LTN brand; LTN Servotechnik GmbH ceased operations 30 April 2026); Specify Motion can help source it or propose an equivalent.

Who makes the LTN frameless resolvers?

The LTN frameless resolvers is made by LTN Servotechnik (HEIDENHAIN Corporate Group (LTN brand; LTN Servotechnik GmbH ceased operations 30 April 2026)) and is listed here for engineers comparing options. Specify Motion is not affiliated with HEIDENHAIN Corporate Group (LTN brand; LTN Servotechnik GmbH ceased operations 30 April 2026); brand names are used only to identify the product.

What is the outer diameter of the LTN frameless resolvers?

The published series minimum outer diameter is 36.83 mm. Individual models and sizes in the LTN frameless resolvers range vary, so check the exact variant against your duty cycle, mounting and environment, or ask our engineers to confirm the right size for you.

Is there an alternative to the LTN frameless resolvers?

We can assess suitable replacement options. On published figures, Novanta Midi Ultra IncOder and Novanta Mini Ultra IncOder are options to assess from our supply network. An engineer confirms the fit against your application before recommending anything.

How is an inductive encoder different from a magnetic encoder?

An inductive encoder uses printed coils and a conductive target, not permanent magnets, so it is not disturbed by stray magnetic fields and contamination in the same way. Magnetic encoders use magnets and Hall or magnetoresistive sensors, which are cheaper but can be affected by external fields.

Can inductive encoders operate underwater?

Many inductive encoders can be fully potted or sealed and are tolerant of water, oil and dirt, which suits subsea and wet applications. The sealing, connector and depth rating must be specified. Check that the specific product is qualified for immersion.

Further reading: How to select an encoder · Magnetic vs capacitive vs optical encoders · Encoders and feedback

Other inductive encoder series

Engineer support

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Tell us how you use the LTN frameless resolvers: the load, speed, duty and environment. Our engineers will confirm whether it is still the right part, find it for you, or propose an alternative that fits better.

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