Series HSD35 Shaftless Optical Encoder

Series HSD35 Optical Encoders


NorthStar Encoders

Quick Specs...

  • Hollowshaft design eliminates mounting bracket, flexible coupling and install labor
  • Bore is electrically and thermally insulated 
  • Single and dual output (with optional high current line driver) 
  • Choice of stamped metal or swivel rod tether 
  • High resolution unbreakable disk 
  • Industrial Duty Latching Connector
  • NEMA 4 / IP67
  • Two Year Warranty

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Overview Industry/Application Specifications Related Info  

Overview / Design Principle:

The NorthStar brand Series HSD35 Sealed Hollowshaft encoder is designed for easy installation on motor or machine shafts. Its hollowshaft design eliminates the need for a flexible shaft coupling, mounting bracket, flower pot, or flange adapter. This not only reduces the installation depth, but also lowers total cost.

The Series HSD35 Sealed Hollowshaft is equipped withan unbreakable disk that resists contamination and meets the demands of the most severe shock and vibration generating processes. Its floating shaft mount and spring tether eliminate bearing loads and flexible shaft couplings to eliminate wear and maintenance.

Series HSD35 optical encoders have complete electrical protection from overvoltage, reverse voltage, and output short circuits. In addition, the Series HSD35 is not only electrically & thermally isolated, but also environmentally sealed withshaft seals at both sides.

Features and Benefits:


  • Unbreakable code disks for 1 to 2048 PPR
  • Flexible mounting
  • Minimizes bearng loads
  • Heavy duty shaft seals; optional extra heavy duty rugged shaft seals
  • Sealed connector - no soldering
  • Insulated from motor housing/shaft temperatures at or above 125°C
  • Direct shaft size minimizes wobble caused by universal inserts


  • Overvoltage, reverse voltage, & output short circuit protection
  • Noise immunity to EN50082-2
  • Bore is electrically isolated from shaft currents
  • Cast housing maximizes noise immunity and durability

Applications/ Industries:

The HSD35 sealed hollow shaft encoder is ideal for motor and machine applications at resolutions to 2500PPR. Choice of stamped metal or swivel rod tether provide flexible mounting for a wide varity of installations: 

Manufacturing, Assembly, Material Handling and any other where a precise, reliable feedback signal is required. (e.g.  Vector Motor and Drive Feedback, Converting Machinery, Packaging Equipment, Paper Processing)

Standard Operating Characteristics
Code: Optical Incremental
Pulses per Revolution: 1-2500
Phasing Sense: A leads B for Clockwise rotation (CW) viewing shaft clamp end
Quadrature Phasing: 90° ± 22.5°
Symmetry: 180° ± 18°
Index: 180° ± 18°

Input Voltage Requirement: 5-26 Volts DC
Current Requirement: 100 mA typical plus line driver load
Output Signals: With Elec Option 0, 1, 2, 4, A & B: 5-26 V Line Driver, 40mA
With Elec Option 3: 5 V Line Driver, 40mA
With Elec Option 5: 5 V Line Driver, 100mA
With Elec Option 6: 5-15 V Line Driver, 100mA
Frequency Response: 0 - 100kHz Data & Index
Electrical Immunity: 1kV ESD, Reverse Polarity, Short Circuit
Connector: 10 pin industrial duty latching, sealed NEMA 4 &12, IP65

Shaft Speed: 3,600 RPM; Max up to 3600 RPM
Mounting Configuration: Flexible mount with anti-rotation arm
Housing Material: Stainless steel and epoxy coated zinc alloy
Available Shaft Sizes: 6 mm to 1.25” thru-shaft style available. See ordering table for sizes.
Allowable Shaft End-Play: ± 0.050”
Allowable Shaft Runout: 0.025” TIR (Subject to RPM Limitation)

Operating Temperature Range: -40°C to +70°C
Storage Temperature Range: -40°C to +90°C
Humidity: to 98% RH (non-condensing)
Shock: 50 Gs for 11 ms
Vibration: 18 Gs @ 5-2000 Hz spectrum

Available Specifications:

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