The Model 755A Size 15 Accu-Coder® is ideal for applications requiring a small, high precision,
high performance encoder. Approximately 1.5" in diameter and 1.5" long, it will fit where
many encoders cannot. Designed with all-metal construction and shielded ball bearings, it
will provide years of trouble-free use. The standard servo mount (S) version is available with
a variety of shaft sizes and lengths. Three additional servo style mounts (S1, S2, S3) are also
available. The optional flange mounting (MF) is ideal for applications requiring a bolt-on, high
precision encoder. With its high reliability and quick delivery, the Model 755A encoder is the

perfect replacement encoder in this size category.

Electrical
Input Voltage.............4.75 to 28 VDC max for temperatures up to
70º C
4.75 to 24 VDC for temperatures between 70º C
to 100º C
Input Current.............100 mA max with no output load
Input Ripple ..............100 mV peak-to-peak at 0 to 100 kHz
Output Format ..........Incremental- Two square waves in quadrature
with channel A leading B for clockwise shaft
rotation, as viewed from the encoder mounting
face. See Waveform Diagrams below.
Output Types ............Open Collector- 100 mA max per channel
Pull-Up- 100 mA max per channel
Push-Pull- 20 mA max per channel
Line Driver- 20 mA max per channel (Meets RS
422 at 5 VDC supply)
Index .........................Occurs once per revolution. The index for units
>3000 CPR is 90º gated to Outputs A and B.
See Waveform Diagrams below.
Freq Response .........100 kHz std; Up to 1 MHz optional. (See
Ordering Guide for availability)
Noise Immunity .........Tested to BS EN61000-4-2; IEC801-3; BS
EN61000-4-4; DDENV 50141; DDENV 50204;
BS EN55022 (with European compliance
option); BS EN61000-6-2; BS EN50081-2
Symmetry .................1 to 6000 CPR: 180º (±18º) electrical at 100
kHz output
6001 to 20,480 CPR: 180º (±36º) electrical
Quad Phasing...........1 to 6000 CPR: 90º (±22.5º) electrical at 100
kHz output
6001 to 20,480 CPR: 90º (±36º)
Min Edge Sep ...........1 to 6000 CPR: 67.5º electrical at 100 kHz
output
6001 to 20,480 CPR: 54º electrical
>20,480 CPR: 50º electrical
Rise Time..................Less than 1 microsecond
Accuracy ...................Instrument and Quadrature Error: For 200 to
1999 CPR, 0.017º mechanical (1.0 arc minutes)
from one cycle to any other cycle. For 2000 to
3000 CPR, 0.01º mechanical (0.6 arc minutes)
from one cycle to any other cycle. Interpolation
error (units > 3000 CPR only) within 0.005º
mechanical. (Total Optical Encoder Error =
Instrument + Quadrature + Interpolation)

echanical
Max Speed ...............7500 RPM. Higher shaft speeds may be
achievable, contact Customer Service.
Shaft Size .................0.250", 5 mm, 6 mm
Shaft Rotation ...........Bi-directional
Radial Shaft Load .....5 lb
Axial Shaft Load .......3 lb
Starting Torque .........0.14 oz-in typical
4.0 oz-in typical for -40º C operation
Moment of Inertia .....2.8 x 10-4 oz-in-sec 2
Max Acceleration ......1 x 105 rad/sec 2
Electrical Conn .........18" cable (foil and braid shield, 24 AWG
conductors), 5- or 8-pin M12 (12 mm) in-line
connector with 18” cable (braid shield), 8-pin
Molex, Terminal Block
Housing.....................Black non-corrosive finish
Bearings....................Precision ABEC ball bearings
Mounting ...................Servo or Optional Flange
Weight .......................3.10 oz servo mount, typical
Environmental
Operating Temp ........0º to 70º C for standard models
-40º to 70º C for low temperature option
0º to 100º C for high temperature option (0º to
85º C for certain resolutions, see CPR Options.)
Storage Temp ...........-25º to +85º C
Humidity ....................98% RH non-condensing
Vibration ....................10 g @ 58 to 500 Hz
Shock ........................50 g @ 11 ms duration