US Digital HD25 Rotary Encoder Description The HD25 is a rugged optical shaft encoder engineered for heavy-duty industrial applications and environments. Its machined aluminum housing, milled from a solid billet and black anodized for protection, conforms to the industry-standard Size 25 package and serves as a direct drop-in replacement for similar encoders.
This rotary encoder can be configured with or without a shaft flat and is available in sealed (IP65) or non-sealed versions. It provides single-ended or differential outputs, each offered in low-voltage (4.5-5.5 VDC) or high-voltage (9.5-30 VDC) signal levels, with an optional index channel. For cable runs longer than 10 ft or installations subject to electrical noise, the differential output is recommended for improved signal integrity.
The HD25 incremental encoder uses a military-spec screw-on connector. After you make your selections in the Product Configurator, compatible cables and connectors will be displayed below and must be ordered separately.
Product Specifications
ENVIRONMENTAL
Parameter
Value
Operating Temperature
Humidity
Vibration (10 to 2kHz, sinusoidal)
20G
Shock (6 milliseconds, half-sine)
75G
Electrostatic Discharge
MECHANICAL
Parameter
Value
Size
NEMA size 25
Housing and Cover Material
Anodized aluminum
Shaft Material
Stainless steel
Weight
17 oz.
Shaft Diameter
0.3748 in. (+0.0000 in. -0.0003 in.)
Shaft Optional Flat Size
.08 in. long x .03 in. deep
Max. Acceleration
100000 rad / sec²
Max. Shaft Speed (1)
Shaft Torque
Max. Shaft Load
Max. Shaft Runout
0.0003 in. T.I.R.
Bearing Life @ 4 Pound Load
2.3 x 10^9 revolutions
Moment of Inertia
2.8 x 10^-4 oz-in-sec²
Technical Bulletin TB1001 - Shaft and Bore Tolerances
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(1) The maximum speed due to electrical considerations is dependent on the CPR. See the EM1 and EM2 product pages.
PHASE RELATIONSHIP
B leads A for clockwise shaft rotation, and A leads B for counterclockwise rotation viewed from the shaft side of the encoder.
ELECTRICAL
Specifications apply over the entire operating temperature range.
Typical values are specified at 25°C.
Output driver IC: ET7272B
For complete details, see the EM1 and EM2 product pages.
PARAMETER
MIN.
TYP.
MAX.
UNITS
CONDITIONS
Supply Voltage (Vs)
Supply Current
138
mA
Low-level Output
0.4
0.5
V
IOL = 20mA
High-level Output
Vs - 2.0
V
IOH = -20mA
Output Rise/Fall Time
700
980
nS
10-PIN CONNECTOR PIN-OUT
PIN
DESCRIPTION
A
A+ channel
B
B+ channel
C
Index+
D
+VDC
E
NC
F
Common
G
Case ground
H
A- channel
I
B- channel
J
Index-
PRODUCT CHANGE NOTIFICATIONS
Title
Date
Description
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HB5M, HB6M & HD25 - PCN 7315
5/17/2023
As part of our ongoing continuous improvement efforts, we are updating our HB5M, HB6M and HD25 series of optical encoders to make product labeling clearer and permanent. The aluminum housing of these encoders will now be anodized black, and labeling will be laser etched onto the surface, providing more contrast and legibility. Previously pin-outs were machined into the housing and product labeling was printed onto an adhesive label that was placed on the side of the product. Product labeling will also now appear on the top surface of the encoder near the pin-out labeling.
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EM1 & EM2 Update - PCN 4199
1/14/2014
Based on our continuous process improvement program, US Digital is changing the current marking method for our EM1 and EM2 encoder modules to a serialization method. This change will allow for each module to have a unique code; the current marking method is based on a date code system that includes all encoder modules produced within a specific week / year. The serialization system will be based on a hexadecimal system.
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EM1 LED Die - PCN 1016
2/7/2013
As part of US Digital's continual assurance of supply strategy, we have qualified additional sources for our LED die used in our EM1 encoder module, which in turn impacts all of the following products:
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Additional Information
Product Notes
Cables and connectors are not included and must be ordered separately.
US Digital® warrants its products against defects in materials and workmanship for two years. See complete warranty for details.
Guides and Additional Documentation
Related
3D Model Downloads
Please
configure your product first
to download a 3D model. (Note: The formats below will become links if there are 3D models available.)
SolidWorks Format
IGES Format
Parasolid Format
STEP Format
Datasheet
Feedback
US Digital's mission is a commitment to quality and constant improvement. If you find an error to a product on this page, please let us know !
Save Your Configuration
Easily keep track of your custom part numbers
What is this feature?
While configuring your encoder, you can save your custom part number at any stage. This helps you keep track of multiple configurations without needing to start over or write anything down.
How does it work?
Click “Add This Configuration to Your List” after selecting your options.
Your saved part number will appear in a mini list below the configurator.
The list is stored locally in your browser and persists across product pages.
Enter a quantity to view default pricing.
What can you do with saved configurations?
When you're ready, visit the Saved Configurations List page to:
Review all saved part numbers
Fill out a form to send your selections to US Digital Customer Service
Receive follow-up to complete your order or get support
Why use it?
Save time by avoiding repeated configurations
Compare multiple part numbers side-by-side
Simplify communication with our support team
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