RC-700
DC Tachometer Generators
SERVO-TEK
®
SERVO-TEK PRODUCTS COMPANY, INC.
www.servotek.com rev. 2
Technical Data
An Industry Standard for over fty years.
A Servo-Tek DC tachometer generator provides a
convenient and economical means of converting
rotational speed into an isolated analog voltage
signal suitable for remote indication and control.
While this catalog contains information on our
most popular models, we also manufacture
countless special tach generators.
Construction
Most of our DC tach generators are housed in
aluminum casings protected in accordance with
Mil-C-5541 or Mil-A-8625 or high performance
plastics. Alnico permanent magnets are used.
Armature shafts are stainless-steel, and rotate
on fully shielded stainless-steel ball bearings.
Commutators are manufactured from an alloy
containing at least 90% silver. Armature
laminations are wound with Isomid insulated wire,
over Teon slot insulation. The entire armature
is then baked, resulting in a NEMA Class H
insulation system.
Linearity
Linearity at any speed is better than 0.1% of the
output at that RPM.
Bidirectional Operation
All Servo-Tek tachometer generators operate in
either rotational direction. That direction can be
determined by output voltage polarity. Output (in
either direction) is held to a tolerance of 0.25% of
the average output.
Stability
Optimum brush and commutator combination
gives 0.1% stability. Highly stable output gives no
evidence of long-term drift.
Breakdown Voltage
Servo-Tek DC tachometer generators are factory
tested with an AC potential of 1250 volts RMS
applied for one second between (either) terminal
and shaft. E-Series units are tested with 500 volts.
Temperature Range
Most of our DC tachometer generators
are designed for continuous operation
in ambient temperatures ranging from
-55ºC to +100ºC. Voltage output at 25ºC will not
deviate by more than 0.01% per degree of change
within the range of -20ºC to +75ºC. All units are
temperature compensated, with the exception of
D-Series and E-Series tach generators.
1086 Gofe Road • Hawthorne, NJ 07506 • sales@servotek.com
Phone (973) 427-3100 • Fax (973) 427-4249 • www.servotek.com
SERVO-TEK
®
Ripple
The ripple RMS value will not exceed 3% of the
DC value at any speed in excess of 40 RPM on
standard units. On the low ripple units, the ripple
RMS value will not exceed 1.5% of the DC value.
A peak to peak ripple of 1.5% is available on some
models.
SB-740A-2
DA-7533A-2
Model Number Mounting
Weight
(Approx.)
Inertia
(Approx.)
oz-in-sec2
V/1000
RPM
RPM
(max)
Armature
Resistance
(dynamic)
Armature
Inductance
(henrys)
Outline
Dimensions
Mounting
Dimensions
Shaft
Size
(in.)
SA-740A-7 Face 3.0 oz 1.32 x 10-4 2.6v 12,000 40Ω 0.024h Fig. 10 Fig. 1 .120
SB-740A-7 Flange 3.0 oz 1.32 x 10-4 2.6v 12,000 40Ω 0.024h Fig. 10 Fig. 2 .120
SA-740A-2 Face 3.0 oz 1.32 x 10-4 7.0v 12,000 350Ω 0.18h Fig. 10 Fig. 1 .120
SB-740A-2 Flange 3.0 oz 1.32 x 10-4 7.0v 12,000 350Ω 0.18h Fig. 10 Fig. 2 .120
SA-757A-2 Face 3.0 oz 1.32 x 10-4 7.0v 12,000 350Ω 0.18h Fig. 11 Fig. 1 .187
SB-757A-2 Flange 3.0 oz 1.32 x 10-4 7.0v 12,000 350Ω 0.18h Fig. 11 Fig. 2 .187
SA-740B-1 Face 4.0 oz 2.27 x 10-4 20.8v 8,000 1000Ω 0.56h Fig. 10 Fig. 1 .120
SB-740B-1 Flange 4.0 oz 2.27 x 10-4 20.8v 8,000 1000Ω 0.56h Fig. 10 Fig. 2 .120
SA-757B-1 Face 4.0 oz 2.27 x 10-4 20.8v 8,000 1000Ω 0.56h Fig. 11 Fig. 1 .187
SB-757B-1 Flange 4.0 oz 2.27 x 10-4 20.8v 8,000 1000Ω 0.56h Fig. 11 Fig. 2 .187
1086 Gofe Road • Hawthorne, NJ 07506 • sales@servotek.com
Phone (973) 427-3100 • Fax (973) 427-4249 • www.servotek.com
SERVO-TEK
®
1086 Gofe Road • Hawthorne, NJ 07506 • sales@servotek.com
Phone (973) 427-3100 • Fax (973) 427-4249 • www.servotek.com
SERVO-TEK
®
1086 Gofe Road • Hawthorne, NJ 07506 • sales@servotek.com
Phone (973) 427-3100 • Fax (973) 427-4249 • www.servotek.com
SERVO-TEK
®
1086 Gofe Road • Hawthorne, NJ 07506 • sales@servotek.com
Phone (973) 427-3100 • Fax (973) 427-4249 • www.servotek.com
SERVO-TEK
®
A-Series Tachometer Generators
Instrument Type:
• 0.120 inch shaft diameter
• Small in size
• Ideally suited to instrumentation applications
Industrial Type:
• 0.187 inch shaft diameter
• Special front-end bearings for radial loads
• Ideal for pulley and belt drive applications
A-Series
1 to 10 volts/1000 RPM
B-Series
11 to 24 volts/1000 RPM
A-Series and B-Series Specications
Maximum Driving Torque for A-Series and B-Series is 0.25 oz-in
Most units listed above are normally in stock
SA-757A-2 and SA-740A-2 SN-763A-2
SB-757B-1 and SU-7346B-1
B-Series Tachometer Generators
As is the case with the A-Series DC tachometer
generator, the B-Series also comes in instrument
and industrial congurations. Depending on the
unit, the output voltage ranges between 11 and 24
V/1000 RPM. Electrical characteristics, ripple,
linearity and temperature effects are the same as
the A-Series.
Other shaft sizes and mounting congurations are
available for most Servo-Tek generators.
Model Number Mounting
Weight
(Approx.)
Inertia
(Approx.)
oz-in-sec2
V/1000
RPM
RPM
(max)
Armature
Resistance
(dynamic)
Armature
Inductance
(henrys)
Outline
Dimensions
Mounting
Dimensions
Shaft
Size
(in.)
SU-780D-1 Flange 8.5 oz 4.54 x 10-4 45v 5,000 1750Ω 1.00h Fig. 10 Fig. 5 .187
SU-7114D-1 Flange 8.5 oz 4.54 x 10-4 45v 5,000 1750Ω 1.00h Fig. 10 Fig. 5 .187
SU-780D-2 Flange 8.5 oz 4.54 x 10-4 33v 5,000 950Ω 0.54h Fig. 10 Fig. 5 .187
SS-779E-1 Synchro 1.25 oz 0.25 x 10-4 3v 12,000 180Ω 0.061h Fig. 12 Fig. 6 .120
1086 Gofe Road • Hawthorne, NJ 07506 • sales@servotek.com
Phone (973) 427-3100 • Fax (973) 427-4249 • www.servotek.com
SERVO-TEK
®
1086 Gofe Road • Hawthorne, NJ 07506 • sales@servotek.com
Phone (973) 427-3100 • Fax (973) 427-4249 • www.servotek.com
SERVO-TEK
®
1086 Gofe Road • Hawthorne, NJ 07506 • sales@servotek.com
Phone (973) 427-3100 • Fax (973) 427-4249 • www.servotek.com
SERVO-TEK
®
1086 Gofe Road • Hawthorne, NJ 07506 • sales@servotek.com
Phone (973) 427-3100 • Fax (973) 427-4249 • www.servotek.com
SERVO-TEK
®
D-Series Tachometer Generators
With rugged construction and high output
voltages, the D-Series tach generator is ideally
suited to a variety of industrial applications.
The ange mounting arrangement provides a
convenient assembly method, and the sturdy
.187 shaft diameter permits the heavier loading
frequently encountered where pulleys or belt
drives are employed. The output bearing is tted
with a seal to help prevent the contamination that
can occur in industrial applications.
With output up to 50V/1000 RPM, D-Series
generators are ideal for applications where high
output voltages are required. Typically, these are
slow speed applications.
D-Series
25 to 50 volts/1000 RPM
E-Series (Subminiature)
.7 to 3 volts/1000 RPM
E-Series Tachometer Generators
The E-Series DC tachometer generator is the
smallest tach generator among those offering
similar technical characteristics. Many
outstanding features make it particularly
suitable for use in all types of servo systems.
Although the diameter is only 0.760” the
E-Series provides up to 3 V/1000 RPM output.
Almost any Servo-Tek DC tachometer generator
can be manufactured with special congurations,
various electrical specs and shaft modications
such as ats, pinions, holes, etc. Consult sales
department regarding your special requirements.
D-Series and E-Series Specications
Maximum Driving Torque for D-Series and E-Series is 0.25 oz-in
Most units listed above are normally in stock
SU-780D-1 SS-779E-1
Model Number Mounting
Weight
(Approx.)
Inertia
(Approx.)
oz-in-sec2V/1000 RPM
RPM
(max)
Armature
Resistance
(dynamic)
Armature
Inductance
(henrys)
Outline
Dimensions
Mounting
Dimensions
Shaft
Size
(in.)
SA-7356F-1 Face 3.0 oz 1.14 x 10-4 7.0v ± 3% 12,000 500Ω 0.38h Fig. 10 Fig. 1 .120
SA-7388F-1 Face 3.0 oz 1.32 x 10-4 7.0v ± 3% 12,000 500Ω 0.38h Fig. 10 Fig. 1 .187
CS-7514F-51C Flange 3.0 oz 1.32 x 10-4 3.0v ± 3% 12,000 130Ω 0.061h Fig. 11 Fig. 3 .250
SB-7483H-1 Flange 4.0 oz 1.96 x 10-4 16.0v ± 3% 8,000 800Ω 0.72h Fig. 11 Fig. 2 .187
SU-780J-1 Flange 8.5 oz 4.54 x 10-4 30v ± 1% 5,000 1050Ω 1.00h Fig. 10 Fig. 5 .187
1086 Gofe Road • Hawthorne, NJ 07506 • sales@servotek.com
Phone (973) 427-3100 • Fax (973) 427-4249 • www.servotek.com
SERVO-TEK
®
1086 Gofe Road • Hawthorne, NJ 07506 • sales@servotek.com
Phone (973) 427-3100 • Fax (973) 427-4249 • www.servotek.com
SERVO-TEK
®
1086 Gofe Road • Hawthorne, NJ 07506 • sales@servotek.com
Phone (973) 427-3100 • Fax (973) 427-4249 • www.servotek.com
SERVO-TEK
®
1086 Gofe Road • Hawthorne, NJ 07506 • sales@servotek.com
Phone (973) 427-3100 • Fax (973) 427-4249 • www.servotek.com
SERVO-TEK
®
Low Ripple Units (F-Series, H-Series and J-Series)
1 to 30 volts/1000 RPM
F-Series (1-8 volts/1000 RPM)
Servo-Tek low ripple DC tachometer generators
satisfy the need for a cost effective, very
low ripple tachometer. In addition to being the
rst economical low ripple units of their type, the
F-Series tachometers incorporate all the desirable
features of the standard units such as temperature
compensation, long brush life, excellent linearity,
and small dimensions.
The ripple voltage does not exceed 1.5% RMS
and 3.5% peak to peak at any speed in excess of
40 RPM on any F-Series, H-Series or J-Series DC
tachometer generator.
J-Series (16-30 volts/1000 RPM)
The J-Series DC tachometer generators are low
ripple units possessing all the same traits as the
F-Series, but with the D-length armature. These
generators are ideal for applications where high
output voltages with low ripple signals are required.
Other shaft sizes and mounting congurations are
available.
F-Series, H-Series and J-Series Specications
Maximum Driving Torque for F-Series, H-Series and J-Series is 0.25 oz-in at 25ºC
Most units listed above are normally in stock
CS-7514F-51C and SA-7356F-1
SB-7483H-1
H-Series (5-16 volts/1000 RPM)
The H-Series DC tachometer generators are low
ripple units possessing all the same traits as the
F-Series, but with the B-length armature. This
means a slightly higher output voltage.
Model Number Mounting
Weight
(Approx.)
Inertia
(Approx.)
oz-in-sec2
V/1000
RPM
RPM
(max)
Armature
Resistance
(dynamic)
Armature
Inductance
(henrys)
Outline
Dimensions
Mounting
Dimensions
Shaft
Size
(in.)
ST-7336A-7 Face 3.0 oz 1.32 x 10-4 2.6v 12,000 40Ω 0.024h Fig. 8 Fig. 8 .120
ST-7336A-2 Face 3.0 oz 1.32 x 10-4 7.0v 12,000 350Ω 0.18h Fig. 8 Fig. 8 .120
ST-7336B-1 Face 4.0 oz 2.27 x 10-4 20.8v 8,000 1000Ω 0.56h Fig. 8 Fig. 8 .120
ST-7337A-2 Face 3.0 oz 1.32 x 10-4 7.0v 12,000 350Ω 0.18h Fig. 8 Fig. 8 .187
ST-7337B-1 Face 4.0 oz 2.27 x 10-4 20.8v 8,000 1000Ω 0.56h Fig. 8 Fig. 8 .187
SU-7346D-1 Flange 8.5 oz 4.54 x 10-4 45v 5,000 1750Ω 1.00h Fig. 8 Fig. 5 .187
1086 Gofe Road • Hawthorne, NJ 07506 • sales@servotek.com
Phone (973) 427-3100 • Fax (973) 427-4249 • www.servotek.com
SERVO-TEK
®
1086 Gofe Road • Hawthorne, NJ 07506 • sales@servotek.com
Phone (973) 427-3100 • Fax (973) 427-4249 • www.servotek.com
SERVO-TEK
®
1086 Gofe Road • Hawthorne, NJ 07506 • sales@servotek.com
Phone (973) 427-3100 • Fax (973) 427-4249 • www.servotek.com
SERVO-TEK
®
1086 Gofe Road • Hawthorne, NJ 07506 • sales@servotek.com
Phone (973) 427-3100 • Fax (973) 427-4249 • www.servotek.com
SERVO-TEK
®
Sealed DC Tachometers
1 to 45 volts/1000 RPM
Servo-Tek’s Ruggedized
PY Alternative (Up to 50 volts)
Sealed DC Tachometer Generator Specications
Ruggedized Tachometer Generators
Servo-Tek ruggedized DC tachometer generators
are designed with sturdy aluminum housings and
strong mounting anges. Other features offered
include extra-heavy armature shafts and bearings.
The mechanical exibility of the ST-13212 allows
for the internal tachometer to be repaired or
replaced, without having to replace the expensive
anodized casting. The ST-13212 supplies outputs
from 2.6 to 50V/1000 RPM and runs at speeds
up to 5000 RPM. The shaft size is 5/16” in
diameter. The ST-12970 comes equipped with a
rubber coupling. It allows the unit to be driven
by a motor shaft with 0.167” wide slot. The
ST-12970 is also available with outputs up to
24V/1000 RPM and can run at high speeds.
Maximum Driving Torque for a sealed DC tachometer generator is 0.7 oz-in
Most units listed above are normally in stock
ST-7337A-2N and ST-7337B-1 ST-13212 and ST-12970
Sealed Tachometer Generators
Servo-Tek manufactures a complete line of sealed
units which are resistant against the harmful
effects of uids. These units employ a one-piece
housing, a special shaft seal, and a form-tted
rubber boot on the terminal end. Servo-Tek sealed
units meet electrical specications after storage at
49ºC with 95% relative humidity for 24 hours.
These units are capable of enduring vibration
with amplitudes up to 0.03” total excursion at
frequencies from 4 Hz to 55 Hz in each of three
mutually perpendicular axes with no evidence of
physical damage. These units are available with a
low ripple output up to 30V/1000 RPM.
Accessories
Output Voltage:
Internal Resistance:
Ripple:
Linearity:
Bidirectional Output:
Polarity:
Temperature Coef cient:
7 VDC ± 5%, no load, per 1000 RPM at 25ºC
270 Ohms typical at 25ºC
5% RMS of DC output voltage at speeds over 40 RPM
0.1% max., 0 to 4000 RPM
0.5% of nominal output in both CW and CCW directions
Red wire positive with CCW rotation viewing shaft end
0.05% per ºC of nominal output at 25ºC from -20ºC to 50ºC
Request a Servo-Tek RC-800 catalog for our complete product line of encoders.
Part Number: ST-7565A-2
Overhung Tachometer
1 to 24 volts/1000 RPM
ST-7565A-2
Other Products
ST-9502
ST-9776
ST50
ST20
1086 Gof e Road • Hawthorne, NJ 07506 • sales@servotek.com
Phone (973) 427-3100 • Fax (973) 427-4249 • www.servotek.com
SERVO-TEK
®
Rubber Couplings
ST-9502-1 ts .120
shafts and ST-9502-2
ts .187 shafts. The
tapered tang is molded
to t a straight slot
0.167”±.005” wide and
3/16” deep.
ST50 Optical Encoder
The ST50, a 2 inch
hollow shaft encoder,
accepts motor shafts
from .236 to .625 inches
OD. It combines 3 phase
brushless commutation
pulses, 2 data channels
and reference index pulse
in a single package.
Flexible Couplings
ST-9776 ts shaft
diameters of up to .375
shafts. They may be
ordered in any mixed or
matched con guration.
When ordering, please
specify both hole sizes.
ST20 Optical Encoder
The ST20, a 2 inch shaft
encoder, is a low cost,
heavy duty solution to
digital feedback. This
unit is available in single
or dual channel with
nearly unlimited mounting
patterns.
ST-7565 Series
Introducing Servo-Tek’s new low-cost overhung
tachometer. This bearingless tach-generator is
small in size and has a black delrin housing and
end plate. Because the Servo-Tek overhung unit
is self-generating and provides an analog output,
it makes for an excellent alternative to the encoder.
No D-A conversion will be necessary! Mounts
easily using a 10-32 threaded shaft. No coupling or
mounting brackets will be required.
Model # “L” “F” “P” “N” “S”
XX-740A 1.701 OMIT OMIT OMIT 0.120 ± .001
XX-740B 2.138 OMIT OMIT OMIT 0.120 ± .001
XX-780B 2.193 0.375 0.062 0.157 0.187 ± .001
XX-780D 3.253 0.375 0.062 0.157 0.187 ± .001
XX-797A 1.701 0.187 0.187 0.110 0.120 ± .001
XX-7103A 1.756 0.375 0.062 0.157 0.187 ± .001
XX-7107D 3.253 OMIT OMIT OMIT 0.187 ± .001
XX-7123A 1.756 OMIT OMIT OMIT 0.187 ± .001
XX-7123B 2.193 OMIT OMIT OMIT 0.187 ± .001
XX-7356F 1.701 OMIT OMIT OMIT 0.120 ± .001
XX-7360F 1.756 0.375 0.062 0.157 0.187 ± .001
Model # “L” “F” “P” “N”
XX-757A 2.240 0.375 0.062 0.157
XX-757B 2.677 0.375 0.062 0.157
XX-796B 2.677 OMIT OMIT OMIT
XX-7483H 2.677 0.375 0.062 0.157
Model # “T” “L” “E” “S”
SS-779E 1.687 1.479 0.375 ± .015 0.1200 ± .0005
SS-7251E 1.687 1.479 0.562 ± .015 0.1870 ± .0002
Model “L” “F” “P” “N” “S”
ST-7336A 1.867 OMIT OMIT OMIT 0.120 ± .001
ST-7336B 2.304 OMIT OMIT OMIT 0.120 ± .001
ST-7337A 1.875 0.375 0.062 0.157 0.187 ± .001
ST-7337B 2.312 0.375 0.062 0.157 0.187 ± .001
XX-7346D 3.633 0.375 0.062 0.157 0.187 ± .001
Model “L” “E” “F” “N” “S”
XX-7114B 2.193 0.562 0.437 0.157 0.187 ± .001
XX-7114D 3.253 0.562 0.437 0.157 0.187 ± .001
XX-7146A 1.701 0.562 0.437 0.110 0.120 ± .001
Model # “L”
SM-762A 2.520
SM-762B 2.957
Figure 10 Instrument/Industrial Conguration Figure 11 Industrial Conguration
Figure 8 Sealed Conguration
Figure 7 Aircraft Conguration
Figure 12 E-Series Tachometers
Figure 9 Flat Shaft Conguration
Figure 1 SA Face Mount Figure 2 SB Flange Mount Figure 3 SD Modied Synchro
Figure 4 SM Aircraft Mount Figure 5 SU Large Flange Mount Figure 6 SS Synchro Mount
Servo-Tek Products Company • 1086 Gofe Road • Hawthorne, NJ 07506
Phone (973) 427-3100 • Fax (973) 427-4249 • www.servotek.com
Specications subject to change without notice
Copyright © 2003 Servo-Tek Products Company
Mounting and Outline Dimensions