Encoders
An encoder turns rotation into an electrical signal – for speed, angle or distance travelled. The first question is not how finely it resolves but what should happen after power-up: if the machine may approach a reference point, an incremental encoder is enough; if the position has to be correct straight away, an absolute encoder is required. Only then come shaft, flange and interface. We list 1,278 items in four categories, ordered along exactly that decision. The level sits under Turck sensors.
Counting or knowing
The incremental encoders (865 items) output square-wave pulses on two channels offset by 90°; the controller counts them and derives the direction of rotation from the phase relationship. After a power failure the count is lost, but these devices are simple, fast and inexpensive. The singleturn absolute encoders (107) encode every angular position uniquely and know their position again immediately – as long as the axis does not exceed one revolution. The multiturn absolute encoders (277) additionally count the revolutions and retain those through a power failure too.
Without shaft and bearings
The contactless encoders (29) take a different route: a passive position transmitter sits on the axis while the sensor head reads its angular position inductively across an air gap. Bearings and coupling are eliminated – precisely the parts that fail first on conventional encoders. Shaft misalignment no longer matters and the devices reach IP68 and IP69K. For washdown applications, mobile hydraulics and anything that vibrates heavily this is the most durable design.
Mechanics: shaft and flange
The mechanics decide whether the encoder fits the machine at all. A solid shaft (590 items) needs a coupling that compensates misalignment; a hollow shaft (435) is pushed directly onto the drive shaft and secured against rotation by a torque support; the blind hollow shaft (253) is the hollow shaft for shaft ends you cannot pass through. The flange patterns follow the standard dimensions: clamping and synchro flange Ø 58 mm are the industry standard, plus Ø 36, 40, 46, 50.8, 63 and 100 mm. Shaft diameters run from 6 to 15 mm and in inches.
Electrics: output and interface
Incremental encoders offer two outputs: push-pull/HTL works at supply voltage level and tolerates long cables in electrically harsh environments, RS422/TTL transmits differentially and is therefore more immune to interference at high pulse frequencies. Absolute encoders deliver the position via SSI, CANopen, SAE J1939, EtherNet/IP or IO-Link, optionally as an analog value of 0…10 V or 4…20 mA. Operating voltages range from 5 VDC for TTL systems to 10…30 VDC for the control cabinet; connection is via M12 connector or fixed cable.
What decides the choice
Three details narrow the choice in practice, and all three are available as filters in every category: resolution (25 to 5000 pulses per revolution on incremental encoders, 12 to 16 bit on absolute encoders), shaft type with diameter and flange type with diameter. Added to these are measuring principle, output function, interface, maximum speed, protection class, connection, operating voltage and housing material. Shaft couplings, flange adapters and connection cables are supplied to match on request. Further brands and sensor types are under sensors, pressure sensors, photoelectric sensors, Baumer sensors and Turck control technology.
Your advantages when buying from us
- 1,278 encoders in four categories – incremental, absolute singleturn and multiturn as well as contactless
- We ship worldwide
- Fast delivery by UPS (parcel) or DSV (pallets) – express shipping available too
- We are happy to advise on resolution, shaft type, flange and interface
- Reseller? Send your reseller enquiry directly to us – discounts depending on volume
- Large company or public authority? Order on account – just ask
