SERVO-TEK
®
SERVO-TEK PRODUCTS COMPANY, INC.
DC Tachometer Generators
www.servotek.com
RC-700
rev. 2
SERVO-TEK
®
1086 Goffle Road • Hawthorne, NJ 07506 • sales@servotek.com
Phone (973) 427-3100 • Fax (973) 427-4249 • www.servotek.com
Technical Data
An Industry Standard for over fifty 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.
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 Teflon slot insulation. The entire armature
is then baked, resulting in a NEMA Class H
insulation system.
Linearity at any speed is better than 0.1% of the
output at that RPM.
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.
Linearity
Bidirectional Operation
Construction
SB-740A-2
Optimum brush and commutator combination
gives 0.1% stability. Highly stable output gives no
evidence of long-term drift.
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.
DA-7533A-2
Stability
Breakdown Voltage
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.
Ripple
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.
Temperature Range
SERVO-TEK
A-Series
®
1086 Goffle Road • Hawthorne, NJ 07506 • sales@servotek.com
Phone (973) 427-3100 • Fax (973) 427-4249 • www.servotek.com
1 to 10 volts/1000 RPM
B-Series
11 to 24 volts/1000 RPM
SB-757B-1 and SU-7346B-1
SA-757A-2 and SA-740A-2
SN-763A-2
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
B-Series Tachometer Generators
As is the case with the A-Series DC tachometer
generator, the B-Series also comes in instrument
and industrial configurations. 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 configurations are
available for most Servo-Tek generators.
Armature
Resistance
(dynamic)
Armature
Inductance
(henrys)
Shaft
Size
(in.)
A-Series and B-Series Specifications
Model Number
Mounting
Weight
(Approx.)
Inertia
(Approx.)
oz-in-sec
2
V/1000
RPM
RPM
(max)
Outline
Dimensions
Mounting
Dimensions
SA-740A-7
SB-740A-7
SA-740A-2
SB-740A-2
SA-757A-2
SB-757A-2
SA-740B-1
SB-740B-1
SA-757B-1
SB-757B-1
Face
Flange
Face
Flange
Face
Flange
Face
Flange
Face
Flange
3.0 oz
3.0 oz
3.0 oz
3.0 oz
3.0 oz
3.0 oz
4.0 oz
4.0 oz
4.0 oz
4.0 oz
1.32 x 10
-4
1.32 x 10
-4
1.32 x 10
-4
1.32 x 10
-4
1.32 x 10
-4
1.32 x 10
-4
2.6v
2.6v
7.0v
7.0v
7.0v
7.0v
12,000
12,000
12,000
12,000
12,000
12,000
8,000
8,000
8,000
8,000
40Ω
40Ω
350Ω
350Ω
350Ω
350Ω
1000Ω
1000Ω
1000Ω
1000Ω
0.024h
0.024h
0.18h
0.18h
0.18h
0.18h
0.56h
0.56h
0.56h
0.56h
Fig. 10
Fig. 10
Fig. 10
Fig. 10
Fig. 11
Fig. 11
Fig. 10
Fig. 10
Fig. 11
Fig. 11
Fig. 1
Fig. 2
Fig. 1
Fig. 2
Fig. 1
Fig. 2
Fig. 1
Fig. 2
Fig. 1
Fig. 2
.120
.120
.120
.120
.187
.187
.120
.120
.187
.187
2.27 x 10
-4
20.8v
2.27 x 10
-4
20.8v
2.27 x 10
-4
20.8v
2.27 x 10
-4
20.8v
Maximum Driving Torque for A-Series and B-Series is 0.25 oz-in
Most units listed above are normally in stock
SERVO-TEK
D-Series
®
1086 Goffle Road • Hawthorne, NJ 07506 • sales@servotek.com
Phone (973) 427-3100 • Fax (973) 427-4249 • www.servotek.com
25 to 50 volts/1000 RPM
E-Series (Subminiature)
.7 to 3 volts/1000 RPM
SU-780D-1
SS-779E-1
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 flange 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 fitted
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.
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 configurations,
various electrical specs and shaft modifications
such as flats, pinions, holes, etc. Consult sales
department regarding your special requirements.
D-Series and E-Series Specifications
Model Number
Mounting
Weight
(Approx.)
Inertia
(Approx.)
oz-in-sec
2
V/1000
RPM
RPM
(max)
Armature
Resistance
(dynamic)
Armature
Inductance
(henrys)
Outline
Dimensions
Mounting
Dimensions
Shaft
Size
(in.)
SU-780D-1
SU-7114D-1
SU-780D-2
SS-779E-1
Flange
Flange
Flange
8.5 oz
8.5 oz
8.5 oz
4.54 x 10
-4
4.54 x 10
-4
4.54 x 10
-4
45v
45v
33v
3v
5,000
5,000
5,000
12,000
1750Ω
1750Ω
950Ω
180Ω
1.00h
1.00h
0.54h
0.061h
Fig. 10
Fig. 10
Fig. 10
Fig. 12
Fig. 5
Fig. 5
Fig. 5
Fig. 6
.187
.187
.187
.120
Synchro 1.25 oz 0.25 x 10
-4
Maximum Driving Torque for D-Series and E-Series is 0.25 oz-in
Most units listed above are normally in stock
SERVO-TEK
®
1086 Goffle Road • Hawthorne, NJ 07506 • sales@servotek.com
Phone (973) 427-3100 • Fax (973) 427-4249 • www.servotek.com
Low Ripple Units (F-Series, H-Series and J-Series)
1 to 30 volts/1000 RPM
CS-7514F-51C and SA-7356F-1
SB-7483H-1
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
first 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.
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.
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 configurations are
available.
F-Series, H-Series and J-Series Specifications
Model Number
Mounting
Weight
(Approx.)
Inertia
(Approx.)
oz-in-sec
2
V/1000 RPM
RPM
(max)
Armature
Resistance
(dynamic)
Armature
Inductance
(henrys)
Outline
Dimensions
Mounting
Dimensions
Shaft
Size
(in.)
SA-7356F-1
SA-7388F-1
SB-7483H-1
SU-780J-1
Face
Face
Flange
Flange
3.0 oz
3.0 oz
3.0 oz
4.0 oz
8.5 oz
1.14 x 10
-4
1.32 x 10
-4
1.32 x 10
-4
4.54 x 10
-4
7.0v ± 3%
7.0v ± 3%
3.0v ± 3%
30v ± 1%
12,000
12,000
12,000
8,000
5,000
500Ω
500Ω
130Ω
800Ω
1050Ω
0.38h
0.38h
0.061h
0.72h
1.00h
Fig. 10
Fig. 10
Fig. 11
Fig. 11
Fig. 10
Fig. 1
Fig. 1
Fig. 3
Fig. 2
Fig. 5
.120
.187
.250
.187
.187
CS-7514F-51C Flange
1.96 x 10
-4
16.0v ± 3%
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