Large Diameter (56mm), Housed Two and Three Channel Optical Encoders

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The HEDS-65XX/HEDL-65XX are high performance two and three channel optical incremental encoders. These encoders emphasize high reliability, high resolution, and easy assembly. Each encoder contains a lensed LED source (emitter), an integrated circuit with detectors and output circuitry, and a codewheel which rotates between the emitter and detector integrated circuit. The outputs of the HEDS-6500 are two single ended square waves in quadrature. The HEDL-65XX outputs are differential.

The HEDS-6540/HEDL-6540 also have a third channel index output in addition to the two quadrature outputs. This index is an active high pulse that occurs once every full rotation of the codewheel. Resolutions up to 1024 Counts Per Revolution are available in the two and three channel versions.

The line driver option offers enhanced performance when the encoder is used in noisy environments, or when it is required to drive long distances.

The line driver option utilizes an industry standard line driver IC (26C31) which provides complementary outputs for each encoder channel. Thus the outputs of the line driver encoder are A and A bar, B and B bar, and I and I bar for three channel versions. Suggested line receivers are 26C32 and 26C33.

The quadrature signals are accessed through a cable and 10-pin female connector.


  • Two Channel Quadrature Output with Optional Index Pulse
  • TTL Compatible Single Ended Outputs on HEDS Series
  • 100 degrees C Operating Temperature
  • Industry Standard 26C31 CMOS Line Driver IC on HEDL Series
  • Easy Assembly, No Signal Adjustment Necessary
  • Resolutions up to 1024 Counts Per Revolution
  • Maximum Shaft Diameter of 5/8 Inches
  • Single 5 V Supply

Lifecycle Status


Substance Compliance

  • RoHS6
    Fully Compliant
Specification Value
Lifecycle Active
Distrib. Inventory Yes
Hub N
RoHS6 Compliant Y
Frequency 100.0
Optical Method Transmissive
Optical Radius (mm) 23.36
Shaft Diameter 3, 3.97, 4.76, 6.35, 4, 5, 6, 8
Resolution 1000 CPR
Shaft Diameter 3, 3.97, 4.76, 6.35, 4, 5, 6, 8