A stator PCB with measurement electronics. A resonant-target PCB on the rotor. You choose the shaft, bearings, housing and motor.
No post-installation calibration procedure. The encoder calibrates itself during the first partial turn, then holds full accuracy at standstill and on every power-up.
The Mini, Midi and Maxi ranges below are sized by stator outer diameter. Their rugged construction serves general industrial applications, commonly at a reduction gearbox output, away from the motor’s electromagnetic field. They do not include screening for in-motor mounting.
For applications requiring greater resistance to shock, vibration and electromagnetic interference, see our separate ruggedised builds for direct-drive motors, currently in development for 85 mm and 115 mm frames.
| Specification | ENC-70 | ENC-75 |
|---|---|---|
| Stator OD | 70 mm | 75 mm |
| Rotor ID | 20 mm | 25 mm |
| Installation height | 12 mm | 12 mm |
| Noise-free resolution | 19-bit | 19-bit |
| Accuracy | ±18″ | ±18″ |
More room through the axis for slip rings, cabling and optics. For direct-drive gimbals and rotary tables. The larger diameter accommodates more fine-scale periods, doubling resolution and accuracy compared with Mini.
| Specification | ENC 80 | ENC 90 | ENC 100 |
|---|---|---|---|
| Stator OD | 80 mm | 90 mm | 100 mm |
| Rotor ID | 30 mm | 40 mm | 50 mm |
| Installation height | 12 mm | 12 mm | 12 mm |
| Noise-free resolution | 20-bit | 20-bit | 20-bit |
| Accuracy | ±9″ | ±9″ | ±9″ |
Clear bores up to 110 mm in a 6 mm installation height. For low-profile gearbox installation, robotic hubs and large-bore stages. Electronics sit beside the receive coils to halve installation height.
| Specification | ENC 125 | ENC 150 | ENC 175 | ENC 200 |
|---|---|---|---|---|
| Stator OD | 125 mm | 150 mm | 175 mm | 200 mm |
| Rotor ID | 35 mm | 60 mm | 85 mm | 110 mm |
| Installation height | 6 mm | 6 mm | 6 mm | 6 mm |
| Noise-free resolution | 20-bit | 20-bit | 21-bit | 21-bit |
| Accuracy | ±9″ | ±9″ | ±5″ | ±5″ |
Contact us to discuss sample availability or to request technical drawings of the Kit Encoder that suits your application.
| Specification | Value |
|---|---|
| Nominal axial gap | 1.4 mm |
| Axial gap tolerance | ±0.5 mm |
| Radial offset | ±0.15 mm |
| Post-installation | Self-calibrating. No post-installation calibration run. |
| Electrical accuracy | ±0.04°, referred to the fine-scale period |
| Internal position update rate | 120 kHz |
| Group delay and bandwidth | 40 µs fixed; −3 dB at 12 kHz |
| Maximum physical speed | 20,000 rpm |
| Long-term repeatability | ±2 counts |
| Thermal drift | ±4 counts within full temperature range |
| Multi-turn, optional | 12-bit |
| Communications | BiSS-C, fixed frame size; SPI compatible |
| Position latch | First falling edge of the BiSS-C clock |
| Maximum clock rate | 10 MHz |
| Data output physical interface | RS422, ±30 V tolerant |
| Power supply | 4.4 to 32 VDC; optional to 60 V |
| Current consumption | < 120 mA at 5 V |
| Reverse polarity protection | To maximum supply voltage |
| Direction and zero setting | Via integral cable |
| Operating temperature | −40 °C to +115 °C |
Relaxed target and stator radial and axial misalignment enable a screw-and-forget assembly sequence, without precision gap setting and without a post-installation calibration run.
Specified within a fine-scale period. Mechanical position accuracy is electrical accuracy divided by the fine-scale period count, N. Mini: N = 8; Midi: N = 16; Maxi: N = 16 or 32, depending on model.
Asynchronous downsampling from the 120 kHz internal update to a nominal 30 kHz BiSS-C request introduces no variable latency. Position is recalculated to the first falling edge of the BiSS-C clock, and a four-sample average provides anti-aliasing ahead of the decimation.
The turn counter is held in non-volatile memory and does not change while the unit is unpowered. If the rotor moves more than 45 degrees in either direction with power removed, the encoder indicates a multi-turn error and continues to do so until reset. To reset the turn count to zero and clear the error, connect the Zero Set signals to 0 V and apply power for more than one second.
The first ruggedised builds are for 85 mm and 115 mm motor frames: ±9 arcsec accuracy, 20-bit noise-free resolution, 34 mm clear bore and N = 16 fine-scale periods. Installation height is 15 mm on the 85 mm frame and 8 mm on the 115 mm frame.
This line is not simply the standard range in a different form factor.
Our ruggedised builds are designed for much higher shock and vibration and high electromagnetic interference. Specified by motor frame size, they mount inside the motor. Aluminium-backed PCBs shield the sensing structure from the motor’s field, with provision for routing the motor cable through the encoder stack.
Our standard Kit Encoders are ruggedised for general industrial use and specified by stator outer diameter. They commonly mount at the output of a reduction gearbox, away from the motor’s electromagnetic field. They are not screened for in-motor mounting.
The Kit Encoders for direct-drive motors are in development. The mechanical detail below is planned, and the shock and vibration figures are current qualification targets, not test results.
| Detail | 85 mm motor frame | 115 mm motor frame |
|---|---|---|
| PCB arrangement | Three PCBs, with separate encoder electronics | Two PCBs, with encoder electronics beside the sensing coils on the stator |
| Stator PCB OD | 95 mm | 125 mm |
| Installation height | 15 mm | 8 mm |
| Clear bore | 34 mm | 34 mm |
| Stator PCB OD / ID | 95 / 47 mm | 125 / 47 mm |
| Separate electronics PCB OD / ID | 95 / 48 mm | Electronics integrated on stator PCB |
| Aluminium substrate | 2 mm thick, attached to both stationary PCBs | 2 mm thick, attached to stator PCB |
| Target PCB OD / ID | 75 / 34 mm | 75 / 34 mm |
| Target mounting | M2.5 fixings on a 39.5 mm pitch circle | M2.5 fixings on a 39.5 mm pitch circle |
| Motor-cable passage | Provision for grommets through both stationary PCBs | Provision for grommets through stator PCB |
The rugged construction includes underfill for critical components, corner bonding for larger ICs, strain relief, capacitors with flexible terminations and conformal coating.
These are qualification targets for the forthcoming builds; verification testing remains to be completed.
| Test | Target |
|---|---|
| Shock | IEC 60068-2-27: 100 g, 11 ms, axial and radial. MIL-STD-810H, Method 516.8, Procedure I: 40 g, 11 ms, terminal-peak sawtooth waveform. Three shocks in each direction along three orthogonal axes, with the encoder operational. |
| Vibration | IEC 60068-2-6: 20 g, 10–2000 Hz, axial and radial. MIL-STD-810H, Method 514.8, Procedure I, Category 20: ground-mobile vehicles, including tracked vehicles, axial and radial. |
Send the frame size, and we can discuss a suitable build. Clear bore, expected volumes and timing can follow. Our designers can join your technical review and answer your team’s questions directly.
We are choosing the next builds now. Customer programmes help set our development priorities.