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  • Specifications
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About QDH20

Quantum Devices, Inc. Model QDH20 provides an improved feedback solution in applications typically using a standard size 20 package. The QDH20 provides encoder feedback in standard industrial mounting configurations with superb mechanical and environmental protection.

Outputs consist of a quadrature A & B with reference pulse Z as a standard feature. The output can be configured with either the 5 to 26 volt OL7272 line driver or open collector outputs. The QDH20 features two heavy-duty bearings holding the output shaft, and two more bearings along with an integral flexible spring mount to isolate the working pieces of the encoder from mechanical stresses.

Design Features:

  • 500 kHz Fundamental Frequency Response
  • High Operating Temperature Option (100° C)
  • Resolutions up to 5000 lines per revolution direct read
  • Flange and Servo Mount Options
  • Solid shaft sizes up to 10mm
  • Hollow shaft sizes up to 0.625″ Diameter
  • High Noise Immunity
  • RoHS Construction

Electrical Specifications

Input Voltage 4.75 to 26 VDC
Input Current Requirements 70mA Typical @ 5VDC Plus Interface Loads
Input Ripple 2% Peak to Peak @ 5VDC
Output Circuits OL7272 High Voltage Line Driver:
VOL = .5V Max @ 20mA Sink
VOH = Vcc-.8V @ 20mA Source
RS422 compatible @ 20mA Source
Open Collector Output:
Sink up to 100mA
Incremental Output Format Quadrature outputs with index pulse.
Accuracy +/-1.0 arc minute
Frequency Response 500 kHz
Symmetry 180 Degrees +/- 10%
Minimum Edge Separation 54 electrical degrees at 100 kHz
Code Incremental
Rise Time Less than 1 µS
Electrical Protection Reverse protected to .6 A Cont. 4 amp for 1 µS.
OL7272 outputs over voltage and short circuit protected

Environmental Specifications

Storage Temperature -40 to 125°C
Operating Temperature -20 to 100°C Typical
Humidity 98% Non-Condensing
Vibration 20 g's @ 50 to 500 CPS
Shock 50 g's @ 11 mS Duration
Sealing Option IP 66 Solid Shaft, IP 64 Hollow Shaft

Mechanical Specifications

Maximum Shaft Speed 8000 RPM (see factory for higher shaft speed)
Hollow Shaft Diameter Tolerance 0.375", 0.500", 0.625" (+.0006" to -.0000")
Solid Shaft Diameter Tolerence 0.250", 0.375", 10mm (+.0000" to -.0004")
Shaft Runout 001 T.I.R. (Max)
Bearings Precision ABEC Double Shielded
Shaft Material 303 Stainless Steel
Bearing Life 1.5 X 10⁹ at Rated Load
Moment of Inertia 3.4 X 10⁻⁴ oz-in-S²
Acceleration 1 X 10⁵ Radians/ Sec²
Starting Torque 1.0 in-oz Max with no seal, 3.0 in-ox with shaft seal
Radial Shaft Loading 40 lbs, (80 lbs Max)
Axial Shaft Loading 40 lbs, (80 lbs Max)
Housing Anodized Aluminum
Weight 13 oz. Typical
Termination Radial Exit: 10, 7 & 6 pin MS, Wire Gland w 24" Cable
Axial Exit: 10, 7 & 6 pin MS, Wire Gland w 24" Cable
Mounting Flange w/ 1.181" Female Pilot
Flange w/ 1.250" Male Pilot
Servo w/ 1.181" Female Pilot
Servo w/ 1.250" Male Pilot
Size 25 Flange and Pilot
Size 25 Servo and Pilot
2.250" Bolt Circle Flex Mount
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