Avtron AV125 SMARTach II Encoders

Avtron AV125 SMARTach II Encoders

Our Largest Encoder!

  • Heavy Mill Duty
  • Up to 7.88" [200mm] Shafts
  • Up to 8192 PPR
  • Removable Sensors
  • Wide-Gap Technology, No Air Gap Adjustment Required
  • Mounts Securely to Motor
  • Outputs Fully Short Circuit Protected
  • Self-Diagnostic LED & Alarm Output
  • Sealed Electronics
  • -40°C to +100°C Operation
  • 3 Year No-Hassle Warranty
  • Excellent for Brake Applications
Outline Drawing

AV125 SMARTach II™ heavy mill duty modular magnetic encoders fit 12.5" motor and NEMA brake flanges. Other models, from 115mm to 8.5", are available to fit other motor sizes.

AV125 is ideal for large motor and brake applications where a large diameter through-shaft is needed.  It permits shafts up to 7 7/8" [200mm] to pass through the encoder, facilitating motor-encoder-brake sandwich construction, as well as hollow shafts for water or air cooling systems to pass through the encoder.  Because AV125 is super-reliable and features removable sensors, you can install it in hard-to-access configurations and locations without risk of downtime.

Quite simply, the AV125 is designed to eliminate encoder failures:  All AV125 electronics are fully encapsulated.  There are no moving wearing parts. AV125 sensors locate over 4X farther from the rotor than the competition; no more sensor/rotor grinding!  The AV125’s high-power outputs have over 50X more capacity.  Miswiring an encoder is common – and it shouldn’t cost you time or money. The AV125 has full output short circuit and reverse voltage protection, plus surge protection.

AV125 SMARTach II sensors digitally self-tune the outputs to eliminate drive trips caused by poor encoder signals. AV125 sensors feature unsurpassed diagnostics. If the encoder signal is not ideal, the alarm output and LED inform the machine operator that the encoder should be checked, before a failure occurs! The AV125 even checks the rotor position before you start running!

Forget tiny optical encoders perched precariously behind your large motor or brake. Specify a heavy duty AV125 encoder!

Operating Power (Each Sensor): 5-24V, 100mA
Output Format: A Quad B with marker (A,A–, B,B–, Z,Z– )
Frequency Range: 0 to 165 KHz
Maximum Instantaneous Current Output: 3000mA*
PPR: 8-8192
Speed: 5000 RPM Max. (contact factory for higher speeds)
Rotor Positioning: Up to +/-0.100" movement/misalignment
Sensor-Rotor Gap: 0.050", +0.015/-0.040" [1.27mm+0.38/-1.0]
Temperature: -40° to 100°C (rotor -40° to 150°C peak)
Electronics: Fully Encapsulated, IP67**
Vibration: 18 g’s
Shock: 1 meter drop test

*Output option 8; see manual for details.
**Connector options may reduce IP rating.

All dimensions are in inches [millimeters]. Specifications and features are subject to change without notice.
Northstar/LakeShore RIM1250™ and SL1250™ are trademarks of Dynapar.
Spare sensors, rotors, through-shaft cover plates, and shaft grounding kits can be ordered separately.

  • SMARTach II sensors find problems before they cause failure
  • Replaces Northstar/LakeShore RIM1250™, NexGen 1250, SL1250™; Avtron M1250 models
  • Resists motor and brake interference noise
  • Reverse voltage protection
  • Mix and match any PPR with any rotor
  • Permits axial movement up to +/-0.100" [+/-2.54mm]
Industry General Food & Beverage Pulp & Paper Wood Products Wind Power Crane & Hoist Metals Mining Marine Oil & Gas

Light Mill Duty

AV20, AV25, AV32, AV6A, AV6M, HS25A, HS35A, HS6A, HS6M, K661,

Mill Duty

AV32, HS35M, K661, M185, M3, M3(small), RAHS35M

Heavy Mill Duty

AV115, AV125, AV45, AV5, AV56, AV56S, AV67, AV85, AV850, AV850Test, AVSK, Carlen Replacement, HS45, K661, M4, M4(small), XR115, XR12, XR125, XR45, XR4F, XR5, XR56, XR85, XR850, XR97, XRB1, XRB2

Severe Mill Duty

AV12, AV30, AV485, AV5, AV685, Carlen Replacement, HS40, K661, M484, M6, M6C, M7, XR12, XR485, XR5, XR685, XR97, XRB1, XRB2,
Avtron's AV125 encoders directly replace competitive models, including:

Lakeshore/Northstar: RIM Tach 1250, RIM 1250, R1, RT1

And other 12.5" C-face and FC-Face mount encoder models including Avtron's M1250.

For direct model replacements, try our cross reference page
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In This Section

  • A Quad B

    A Quad B refers to the set of output quadrature signals from an incremental quadrature encoder to indicate speed and direction, including complements: A, A NOT, B, B NOT (, , , ). Most Avtron encoders offer A Quad B output at no extra cost.  For more information on quadrature- Wikipedia: http://en.wikipedia.org/wiki/Quadrature_phase

  • Cam Screw Rotor™

    A Cam Screw Rotor eliminates the problems associated with slipping rotors of other types; it uses two cam (eccentric) head screws. The screws are preloaded into the rotor; simply rotate them (approximately 90°-180°) to fully engage the shaft (4-6 ft-lbs) using a standard hex (Allen) wrench. Cam screw rotors are available on AV850, AV56, AV67, AV85, and AV115 THIN-LINE II™ encoders. Cam Screw Rotor Patent # 7,485,997. Cam Screw Rotor™ is a trademark of Avtron.

  • Encoder

    A device which indicates position and speed via a set of digital outputs. Incremental encoders output quadrature (A Quad B) signals, and may add a marker pulse once per revolution.  Absolute encoders typically indicate position via a digital message, a set of parallel outputs, or analog values.

  • Face or Flange Mount

    A machined surface (NEMA 56C, NEMA FC) on the non-drive end of the motor is used to mount bearingless or pancake encoders such as Avtron AV56 THIN-LINE II™ encoders. Solid shaft, coupled tachometers also flange mounted using flange adapters, also called flowerpots.

  • Heavy Mill Duty

    Heavy Mill Duty encoders are designed to withstand temperature cycling, extreme temperatures, contaminants, bearing loads, and physical force.

  • Incremental Encoder

    An encoder that produces pulses in proportion to distance moved or rotated. Incremental encoders can also have a marker pulse Z, Z NOT (, ) once per revolution to provide a position reference. Avtron produces a full range of incremental rotary encoders.

  • Industrial EPIC

    The preferred encoder connector of most users in North America. It contains a full size terminal strip and, unlike the MS connector, requires no soldering for quick field connections. Avtron offers pin-for-pin exact replacements for competitors’ models using industrial EPIC® style connectors. EPIC® is a registered trademark of the Lapp Group.

  • Magnetic Encoder

    Magnetic and magnetoresistive encoders typically use a magnetized rotor with north and south poles lined up around the perimeter of the disk. A magnetoresistive sensor detects the transitions, and these are the counts or pulses generated by the encoder. Magnetic encoders withstand dirt, dust, water, and temperature changes far better than optical encoders.

  • Magnetic Rotor

    A magnetized disk with multiple north and south poles lined up around the perimeter of the disk. A magnetoresistive sensor detects the transitions and generates the pulses generated by the magnetic encoder.

  • Magnetoresistive Sensor

    A sensor that detects the magnetic poles on an encoder's magnetic rotor and transforms them into pulses. Avtron magnetoresistive (MR) sensors use advanced technology to reject external magnetic signals such as brake solenoids and motor magnetic fields. MR sensors enable Avtron magnetic encoders to ignore dirt, oil, water, and other contaminants.

  • Modular Encoders

    Modular Encoders mount to a machined C-face or flange adapter on the motor (drive or non-drive end). Modular encoders consist of a rotor that mounts on the shaft, and a stator that bolts to the motor frame. Modular encoders are very rugged, and Avtron encoders feature Wide-Gap sensors to avoid complex shimming or fitting to the motor. Modular C-face encoders are typically used on DC motors; but some AC motors, such as Rockwell’s RPM III AC and Marathon’s Blue and Black Max motors, have C-faces standard on the non-drive end for mounting an encoder.

  • MR

    Magnetoresistive (MR) sensors are used in Avtron encoders to provide high accuracy and superior reliability versus optical sensing systems.  For more information on magnetoresistivity:  Wiki:  http://en.wikipedia.org/wiki/Magnetoresistive

  • MS Connector

    The most used encoder connector style in North America. Available in 6, 7, and 10 pin versions, with 10 pins being the most common. Avtron offers pin-for-pin exact replacements for competitors’ models using MS connectors. MS connectors are extremely reliable but require soldering. Many users prefer industrial EPIC ® style connectors instead. EPIC® is a registered trademark of the Lapp Group.

  • PPR

    Pulses Per Revolution. Most Avtron encoders output quadrature pulses, with four times as many lines as pulses. Often lines can be counted in the drive/speed controller for higher resolution applications.

  • Quadrature

    To determine which direction an encoder is revolving, encoders output quadrature signals: two streams of pulses, A & B, generated at 90° timing angles. (Also called A Quad B) A leading B indicates rotation in one direction; B leading A indicates the encoder is rotating in the opposite direction. Example: “A leads B with clockwise rotation as viewed from the encoder face on an HS45 encoder." Many encoders with quadrature outputs also have complementary outputs: A NOT and B NOT signals.

  • Resolution

    Resolution describes how many individual slices or positions can be reported by an incremental or absolute encoder.  For incremental encoders the number of PPR (pulses per revolution) expresses resolution; for absolute encoders, PPR, or counts per turn or bits of resolution may be listed.

  • Rotor

    The disk-shaped portion of the modular encoder that is mounted on the motor shaft. Avtron modular encoders use magnetic rotors.

  • Sandwich

    An older style of encoder that fits between an existing solid shaft coupled tachometer and the motor. It is commonly replaced by modular encoders such as the Avtron AV56 THIN-LINE II™.

  • Sensor Crash

    When the rotating disk in an encoder contacts the sensor (optical or magnetic/magnetoresistive), it damages or destroys the sensor. Sensor crashes can be caused by excessive vibration, shaft runout, or alignment problems in encoder mounting. Avtron encoders feature Wide-Gap technology to eliminate sensor crashes.

  • Stator

    The portion of a modular encoder that bolts to the motor frame.

  • Wide-Gap Technology

    Avtron encoders use special optical sensors and magnetoresistive sensors, combined with proprietary circuit designs to allow the sensor to be located much farther from the magnetic rotor or optical disk. This eliminates sensor crashes and makes mounting easy and forgiving of mechanical variation.

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