HEDB-9040-B12 Avago Technologies US Inc., HEDB-9040-B12 Datasheet - Page 2
![Optoelectronic Miscellaneous, Other](/photos/31/20/312002/hedb_9x40_wht_sml.jpg)
HEDB-9040-B12
Manufacturer Part Number
HEDB-9040-B12
Description
Optoelectronic Miscellaneous, Other
Manufacturer
Avago Technologies US Inc.
Series
HEDB-9040r
Datasheet
1.HEDB-9140-A12.pdf
(5 pages)
Specifications of HEDB-9040-B12
Encoder Type
Optical
Output Type
Quadrature with Index (Incremental)
Pulses Per Revolution
1000
Voltage - Supply
5VDC
Actuator Type
6mm Open Center
Detent
No
Built In Switch
No
Mounting Type
Chassis Mount, Motors
Termination Style
Terminal Pins
Number Of Channels
3
Product
Optical
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Orientation
-
Rotational Life (cycles Min)
-
Lead Free Status / Rohs Status
Lead free / RoHS Compliant
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
between the actual shaft position and the position
indicated by the encoder cycle count.
2
∆Θ
∆Θ
∆Θ
∆Θ): The normalized angular difference
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 φ φ φ φ ): The number of electrical degrees between
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 φ φ φ φ ): The deviation of the phase from its
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