HEDB-9040 and HEDB-9140
Three Channel Optical Incremental Encoder
Modules Bundle With Codewheel
Data Sheet
Description
The HEDB-9040 and HEDB-9140 series are three
channel optical incremental encoder modules offered
with a codewheel. When used with a codewheel, these
low cost modules detect rotary position. Each module
consists of a lensed LED source and a detector IC
enclosed in a small plastic package. Due to a highly
collimated light source and a unique photodetector
array, these modules are extremely tolerant to
mounting misalignment.
The HEDB-9040 and 9140 has two channel quadrature
outputs plus a third channel index output. This index
output is a 90 electrical degree high true index pulse
which is generated once for each full rotation of the
codewheel.
The HEDB-9040 is designed for use with a HEDS-6140
codewheel which has an optical radius of 23.36 mm
(0.920 inch).The HEDB-9140 is designed for use with a
HEDS-5140 codewheel which has an optical radius of
11.00 mm (0.433 inch).
The quadrature signals and the index pulse are
accessed through five 0.025 inch square pins located
on 0.1 inch (pitch) centers.
Features
•
Two Channel Quadrature Output with Index Pulse
•
Resolution from 100 CPR Up To 1024 CPR (Counts
Per Revolution)
•
Low Cost
•
Easy to Mount
•
No Signal Adjustment required
•
Small Size
•
Operating Temperature: -40
o
C to 100
o
C
•
TTL Compatible
•
Single 5V Supply
Applications
The HEDB-9040 and 9140 provide sophisticated motion
control detection at a low cost, making them ideal for
high volume applications. Typical applications include
printers, plotters, tape drives, and industrial and factory
automation equipment.
Note: Avago Technologies encoders are not recommended for use
in safety critical applications. Eg. ABS braking systems, power
steering, life support systems and critical care medical equipment.
Please contact sales representative if more clarification is needed.
1
Theory of Operation
The HEDB-9040 and 9140 is emitter/detector modules.
Coupled with a codewheel, these modules translate
the rotary motion of a shaft into a three-channel digital
output.
As seen in Figure 1, the modules contain a single Light
Emitting Diode (LED) as its light source. The light is
collimated into a parallel beam by means of a single
polycarbonate lens located directly over the LED.
Opposite the emitter is the integrated detector circuit.
This IC consists of multiple sets of photodetectors and
the signal processing circuitry necessary to produce
the digital waveforms.
The codewheel rotates between the emitter and
detector, causing the light beam to be interrupted by
the pattern of spaces and bars on the codewheel.
The photodiodes which detect these interruptions are
arranged in a pattern that corresponds to the radius
and design of the code-wheel. These detectors are also
spaced such that a light period on one pair of detectors
corresponds to a dark period on the adjacent pair of
detectors.
The photodiode outputs are then fed through the
signal processing circuitry resulting in A, Abar, B, Bbar,
I and Ibar. Comparators receive these signals and
produce the final outputs for channels A and B. Due to
this integrated phasing technique, the digital output
of channel A is in quadrature with that of channel B
(90 degrees out of phase).
Definitions
Note: Refer to Figure 2
Count (N):
The number of bar and window pairs or
counts per revolution (CPR) of the codewheel.
One Cycle (C):
360 electrical degrees (°e), 1 bar and
window pair.
One Shaft Rotation:
360 mechanical degrees, N cycles.
Position Error (∆Θ
The normalized angular difference
∆Θ):
∆Θ
between the actual shaft position and the position
indicated by the encoder cycle count.
Cycle Error (∆C):
An indication of cycle uniformity. The
∆
difference between an observed shaft angle which
gives rise to one electrical cycle, and the nominal
angular increment of 1/N of a revolution.
Pulse Width (P):
The number of electrical degrees that
an output is high during 1 cycle. This value is nominally
180°e or 1/2 cycle.
Pulse Width Error (∆P):
The deviation, in electrical
∆
degrees, of the pulse width from its ideal value of
180°e.
State Width (S):
The number of electrical degrees
between a transition in the output of channel A and
the neighboring transition in the output of channel B.
There are 4 states per cycle, each nominally 90°e.
Phase (φ):
The number of electrical degrees between
φ
the center of the high state of channel A and the center
of the high state of channel B.
This value is nominally 90°e for quadrature output.
Phase Error (φ):
The deviation of the phase from its
φ
ideal value of 90°e.
Direction of Rotation:
When the codewheel rotates
in the clockwise direction viewing from top of the
module (direction from V to G), channel A will lead
channel B. If the codewheel rotates in the opposite
direction, channel B will lead channel A.
Optical Radius (Rop):
The distance from the
codewheel’s center of rotation to the optical center
(O.C) of the encoder module.
Index Pulse Width (Po):
The number of electrical
degrees that an index is high during one full shaft
rotation. This value is nominally 90°e or 1/4 cycle.
Specification
For encoder electrical, mechanical specifications,
codewheel technical specifications and additional
informations pls refer to :
•
HEDS-9040 /9140 datasheet.
•
HEDS / HEDG / HEDM – 51xx
Datasheet
/61xx
Codewheel
2
Bundle Part Number Breakdown List
Note :The bundle part HEDB-9040/9140 consists of HEDS-9040/9140 and HEDS-6140/5140. The table below provides the breakdown list.
HEDB - 9040 - CPR
Shaft Diameter
CPR
CPR
00
Encoder Module : HEDS-9040 -
Codewheel : HEDS - 6140 -
Shaft Diameter
HEDB - 9140 - CPR
Shaft Diameter
CPR
00
Encoder Module : HEDS-9140 -
Codewheel : HEDS - 5140 -
CPR
Shaft Diameter
For product information and a complete list of distributors, please go to our web site:
www.avagotech.com
Avago, Avago Technologies, and the A logo are trademarks of Avago Technologies, Limited in the United States and other countries.
Data subject to change. Copyright © 2006 Avago Technologies Pte. All rights reserved.
5989-4043EN - May 29, 2006
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