RT
Vishay Sfernice
Wirewound Rheostats and Potentiometers
Characteristics
FEATURES
RHEOSTAT MODE
• 12 W to 500 W at 25 °C
• CCTU 05-03B
The performance of RT-RTE rheostats exceeds the
requirements of specification CCTU 05-03B.
They have been designed for heavy duty applications such
as repeated overloads, transients, shock and vibration
conditions.
RT VITREOUS SERIES
G
Six sizes are available capable of dissipating 12, 25, 55, 100,
250 or 500 watts at 25 °C.
The resistive wire is protected by a proprietary Vishay
Sfernice enamel fired at high temperature and free from any
compound that could cause corrosion of the wire.
The maximum operating temperature of the RT series is
320 °C.
Z
POTENTIOMETER MODE
GANGED UNITS
Ganged units are available with different combinations of
power and ohmic values (see data-sheet).
Z
GRADED WINDINGS
G
Imax
These are recommended when the ratio is -------------- > 2
Imin
CURRENT INCREASE FACTOR OVER NOMINAL
MAXIMUM OVERLOAD
In rheostat use, the winding current decreases in relation to
the number of turns being used.
When part of the winding is used the current can be
increased in accordance with the graph on the left.
Substantially heavier overloads can be applied in short
impulses and we would be pleased to advise on this type of
application, on receipt of the following information:
- proposed rheostat usage
- current level
- operating cycles specifying duration of overload “ON”,
”OFF” periods.
1.28
1.24
1.20
1.16
1.12
1.08
1.04
1
0
15
30
45
60
75
90
100
% WINDING IN SERVICE
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78
For technical questions, contact: sfer@vishay.com
Document Number: 50024
Revision: 18-Dec-06
RT
Wirewound Rheostats and Potentiomaters
Characteristics
Vishay Sfernice
SPECIAL FEATURES
OFF POSITION RIGHT
Code No.: 213600
OFF POSITION LEFT
Code No.: 213700
c
c
a
b
b
IDLE LUG RIGHT
Code No.: DB2
Not available for RT12 and RT500
IDLE LUG LEFT
Code No.: DB1
Not available for RT12 and RT500
a
c
a
b
FIXED TAPPINGS, ONE OR MORE
Code No.: RTP
Not available for RT12 and RT500
DOUBLE MINI SWITCH
Not available for RT12
L
c
a
Idle lug
c
Idle lug
c
b
b
REDUCED LEFT TRAVEL
Not available for RT12 and RT500
REDUCED RIGHT TRAVEL
Not available for RT12 and RT500
c
a
a
c
b
b
Other special features are available.
Please consult Vishay Sfernice for all of your rheostat requirements.
All the positionings are defined when the shaft end is viewed (contrary to the above windings) clockwise detent.
DIMENSIONS
CODE
L
mm
RT25
219410
29
RT55
219430
33
RT100
219450
33
RT230
219470
35
RT500
219480
35
DOUBLE MINI SWITCH FOR SERIES AND SIZE
Document Number: 50024
Revision: 18-Dec-06
For technical questions, contact: sfer@vishay.com
www.vishay.com
79
RT
Wirewound Rheostats and Potentiometers
Characteristics
Vishay Sfernice
POWER RATING CHART
% RATED POWER
100
75
RT
50
RT
E
25
0
0
50
100
150
200
250
300
350
AMBIENT TEMPERATURE IN DEGREES CELSIUS
TEMPERATURE RISE
00
RT
5
RT
230
00
RT
1
5
RT
55
250
RT
2
300
RT
12
TEMPERATURE RISE AT HOTTEST POINT °C
350
200
150
100
50
0
1
5
10
100
1000
NOMINAL DISSIPATION IN WATTS
ORDERING INFORMATION
VITREOUS
RT
25
MODEL STYLE
L
AS
± 10 %
B010
e
LEAD
SHAFT VARIATION SPECIAL WINDING COMMAND OHMIC TOLERANCE PACKING
VALUE
(PB)-FREE
LOCKING
LAW
DESIGN
SHAFT
Optional
DEVICE
Method N°
Optional
Optional
ACCESOIRES
3K3
Il special,
please
supply a
drawing
ACC
BOUTON
60JF
e
DB1
MODEL
KNOB
DIAL
LEAD (Pb)-FREE
SPECIAL FEATURES
IDLE LUG LEFT
SAP PART NUMBERING GUIDELINES
RT
25
L
MODEL
STYLE
LAW
ACCRF
BOUTON
60JF
MODEL
TYPE
STYLE
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80
AS
3301
K
B
OHMIC VALUE
TOLERANCE
PACKING
For technical questions, contact: sfer@vishay.com
Document Number: 50024
Revision: 18-Dec-06
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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