Model 308
Vishay Spectrol
2" (50.8 mm) Single Turn Conductive Plastic
Precision Potentiometer
FEATURES
•
•
•
•
•
Bushing mount and servo mount types available
Virtually infinite resolution
RoHS
COMPLIANT
Up to 6 sections available
Rotational life exceeds 20 million shaft revolutions
Co-Molded track and Multi-Finger wiper provide low noise
signal
•
Large ohmic value range: 500
Ω
to 100 kΩ
ELECTRICAL SPECIFICATIONS
PARAMETER
Total Resistance
Standard Range
Tolerance
Linearity (Independent)
Electrical Angle
Power Rating
Section 1
Additional Sections
Output Smoothness
Insulation Resistance
Dielectric Strength
Taps (Extra)
Phasing
Temperature Coefficient of Resistance
STANDARD
± 10 %
STANDARD
± 0.25 %
350° ± 2°
2.0 W at 70 °C ambient derated to zero at 125 °C (400 V
DC
maximum)
75 % of the rating of section 1
0.1 % maximum
1000 MΩ minimum 500 V
DC
1000 V
RMS
, 60 Hz
Extra taps available as special
Points at which output ratio is 0.5 aligned ± 1° (ref. to section 1)
± 400 ppm/°C maximum
500
Ω
to 100 kΩ
SPECIAL
±5%
SPECIAL
± 0.05 %
MATERIAL SPECIFICATIONS
Housing and Lids
Shaft and Clamp Rings
Terminals
Bushing Mount Hardware
Lockwasher Internal Tooth:
Panel Nut:
Aluminum, anodized
Stainless steel, non-magnetic
non-passivated
Brass, gold plated for solderability
Steel, nickel plated
Brass, nickel plated
ENVIRONMENTAL SPECIFICATIONS
Vibration
Shock
Salt Spray
Rotational Life
Load Life
Temperature Range
15 g thru 2000 Hz
50 g
96 h
Servo: 20 million shaft revolutions
Bushing: 5 million shaft revolutions
900 h
- 55 °C to + 125 °C
ORDERING INFORMATION/DESCRIPTION
The Model 308 can be ordered from this data sheet with a variety of alternate characteristics, as shown. For most rapid service on your order,
please state:
308
MODEL
B
MOUNTING
B:
Bushing
S:
Servo
1
NUMBER OF SECTIONS
Up to 6
20K
TOTAL RESISTANCE OF EACH SECTION
Beginning with the section nearest the mounting end
BO1
PACKAGING
Box of 1 piece
Other characteristics will be standard as described on this data sheet. If special characteristics are required, such as: special linearity tolerance,
special resistance tolerance, extra taps, non-linear functions, etc., please state these on your order and allow additional lead time for delivery.
SAP PART NUMBERING GUIDELINES
308
MODEL
S
STYLE
B:
Bushing
S:
Servo
1
GANG NUMBER
From 1 up to 6
203
OHMIC VALUE GANG
20K
N
O
1
B01
PACKAGING
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For technical questions, contact: sfer@vishay.com
Document Number: 57058
Revision: 22-Mar-07
Model 308
2" (50.8 mm) Single Turn Conductive Plastic
Precision Potentiometer
DIMENSIONS
in inches (millimeters)
SERVO MOUNT: 308 S
± 0.010
Vishay Spectrol
1
0.340 MIN.
(8.64)
0.093
(2.36)
0.831
(21.10)
± 0.031
0.625
(15.88)
0.073 MIN.
(1.85)
15° TYP.
± 5°
45°
3
1
2
± 0.015
Ø 2.000
(50.80)
Ø 1.812
MAX.
(46.02)
Ø 1.8750
(47.62)
+ 0.0000
- 0.0005
1.200 R MAX.
(30.48)
Ø 2.000
(50.80)
MTG. FACE
0.062
(1.57)
Ø 0.2497
- 0.0003
(6.34)
+ 0.0000
1.140 R MAX.
(28.96)
BUSHING MOUNT: 308 B
± 0.015
1
± 0.031
0.705
(17.91)
0.239 MIN.
(6.07)
0.875
(22.22)
± 0.010
0.375
(9.52)
0.062
(1.57)
Ø 0.2497
(6.34)
+ 0.0000
- 0.0003
Ø 0.4062
(10.32)
+ 0.0000
- 0.0010
± 0.015
Ø 1.375
(34.92)
± 0.015
Ø 2.000
(50.80)
2
1
CW
3
SCHEMATIC
0.010
(0.25)
3
/
8
- 32 UNEF - 2A
MTG. FACE
1
ADD 0.500 ± 0.002 (12.70) FOR EACH
ADDITIONAL SECTION
TOLERANCES: UNLESS OTHERWISE NOTED.
DECIMALS ± 0.005 ANGLES ± 2°
POWER RATING CHART
(Ratings for cup No. 1.
Additional cups 75 % of values shown)
RATED POWER IN W
RESISTANCE ELEMENT DATA
RESISTANCE
VALUES
(Ω)
500
1K
2K
5K
10K
20K
50K
100K
MAXIMUM VOLTAGE
APPLICABLE
(V)
32
45
71
100
141
224
316
350*
4
3
2
1
0
20
40
60
80
100
120
140
160
* Maximum voltage allowable
AMBIENT TEMPERATURE IN °C
Document Number: 57058
Revision: 22-Mar-07
For technical questions, contact: sfer@vishay.com
www.vishay.com
39
Model 308
Vishay Spectrol
2" (50.8 mm) Single Turn Conductive Plastic
Precision Potentiometer
MECHANICAL SPECIFICATIONS
PARAMETER
Rotation
Bearing Type
Servo Mount:
Bushing Mount:
Ganging
Torque (Maximums)
Mounting
Servo, 1 Section
Bushing, 1 Section
Each Additional Section
Runouts (Maximums)
Shaft (TIR/in)
Pilot Dia. (TIR)
Lateral (TIR)
Shaft End Play
Shaft Radial Play
Moment of Inertia
Weight
Single Section
Each Additional Section
360° (continuous)
Ball bearing
Sleeve bearing
6 sections maximum
Terminal alignment, added sections,
within ± 10° of section 1 terminals
STARTING
1.0 oz. - in (72.00 g - cm)
1.7 oz. - in (122.40 g - cm)
0.6 oz. - in (43.20 g - cm)
SERVO
0.002" (0.05 cm)
0.002" (0.05 cm)
0.003" (0.08 cm)
0.005" (0.13 cm)
0.002" (0.05 cm)
2.0 g - cm
2
per section maximum
4.0 oz. (127.57 g)
1.2 oz. (34.02 g)
RUNNING
0.5 oz. - in (36.00 g - cm)
1.0 oz. - in (72.00 g - cm)
0.4 oz. - in (28.80 g - cm)
BUSHING
0.002" (0.05 cm)
0.002" (0.05 cm)
0.005" (0.13 cm)
0.005" (0.13 cm)
0.003" (0.08 cm)
MARKING
Unit
Identification
Units shall be marked with Spectrol name, model no, and data code, and on each section, resistance,
resistance tolerance, linearity and terminal identification
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For technical questions, contact: sfer@vishay.com
Document Number: 57058
Revision: 22-Mar-07
Legal Disclaimer Notice
Vishay
Disclaimer
All product specifications and data are subject to change without notice.
Vishay Intertechnology, Inc., its affiliates, agents, and employees, and all persons acting on its or their behalf
(collectively, “Vishay”), disclaim any and all liability for any errors, inaccuracies or incompleteness contained herein
or in any other disclosure relating to any product.
Vishay disclaims any and all liability arising out of the use or application of any product described herein or of any
information provided herein to the maximum extent permitted by law. The product specifications do not expand or
otherwise modify Vishay’s terms and conditions of purchase, including but not limited to the warranty expressed
therein, which apply to these products.
No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted by this
document or by any conduct of Vishay.
The products shown herein are not designed for use in medical, life-saving, or life-sustaining applications unless
otherwise expressly indicated. Customers using or selling Vishay products not expressly indicated for use in such
applications do so entirely at their own risk and agree to fully indemnify Vishay for any damages arising or resulting
from such use or sale. Please contact authorized Vishay personnel to obtain written terms and conditions regarding
products designed for such applications.
Product names and markings noted herein may be trademarks of their respective owners.
Document Number: 91000
Revision: 18-Jul-08
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