Document Number: 30232
Revision 10-May-01
www.vishay.com
142
Wirewound Fuse Resistors
Vishay Dale
For technical questions, contact ww2aresistors@vishay.com
Fast Acting, Molded Styles
Custom Designed For Your Application
The following are offered as examples of reliable designs. Hundreds of possible combinations are available for meeting your requirements.
Contact factory by using email address in the footer of this page, for assistance. Higher wattages available.
* The Continuous Current Rating applies only to values equal to or less than the Crossover Value. The Continuous Power Rating applies only
to values equal to or higher than the Crossover Value.
Note: Be aware that the inherent compromise involved between resistive and fusing functions sometimes makes certain exact combinations
unattainable. However, in nearly all cases, this does not prevent the production of a functional, reliable fuse resistor thoroughly capable of
meeting application requirements.
RS-1A-209 402Ω5%
MODEL RESISTANCE TOLERANCE
Ω±%
If a MODEL listed in TYPICAL ELECTRICAL SPECIFICATIONS table does not meet your requirements, then please include the following
information. It will enable us to choose the best design for your application.
1. Operating wattage or current, ambient temperature and required resistance stability. (% ∆R/1000 hours.)
2. Fusing wattage or current and maximum “blow” time. Also, minimum “blow” time, if applicable.
3. Nominal resistance and maximum allowable resistance tolerance, (5% to 10% preferred).
4. Maximum allowable physical size.
5. Voltage to be interrupted.
6. Frequency of power source, wave form and a brief description of your application.
ORDERING INFORMATION
1.0 WATT CONTINUOUS POWER*
TYPICAL ELECTRICAL SPECIFICATIONS
FEATURES
•Low temperature coefficient typical of wirewound resistor
•High temperature silicone molded package
•Performs function of resistor and series fuse and provides
predictable fusing times
•Complete welded construction
•No flaming or distortion of unit under fusing conditions
•Ideal for Squibb circuit applications and protection of
semi-conductor devices
•Negligible noise and voltage coefficient
MODEL FUSING CURRENT TYPICAL FUSING TIME RESISTANCE RANGE CONTINUOUS CURRENT CROSSOVER VALUE
Amperes Milliseconds ΩAmperes Ω
± 5%, ± 10% Available
RS-1A-209 0.5 4 49 - 500 0.10 100.0
RS-1A-118 1.0 9 6.8 - 185 0.25 16.0
RS-1A-212 1.25 8 4.7 - 107 0.30 11.11
RS-1A-213 1.5 15 3.5 - 68 0.35 8.16
RS-1A-143 2.0 15 2.2 - 35 0.40 6.25
RS-1A-214 2.5 23 1.7 - 23 0.45 4.94
RS-1A-162 3.0 48 1.1 - 12 0.55 3.31
RS-1A-208 4.0 47 0.72 - 6.44 0.75 1.78
RS-1A-207 6.0 70 0.35 - 2.17 1.0 1.0
RS-1A-215 8.0 48 0.29 - 1.61 1.25 0.64
RS-1A-173 10.0 50 0.23 - 1.16 1.50 0.44
RS-1A-216 15.0 35 0.19 - 0.82 1.75 0.33
RS-1A-217 20.0 46 0.12 - 0.42 2.0 0.25
FUSING PARAMETERS
www.vishay.com
143
Wirewound Fuse Resistors
Vishay Dale
Document Number: 30232
Revision 10-May-01 For technical questions, contact ww2aresistors@vishay.com
AMBIENT TEMPERATURE °C
0 50 75 100 125 150 175 200
120
100
80
60
40
20
0
% OF RATED POWER
Derating
MODEL A B
1.0 Watt 0.422 ± 0.015 [10.72 ± 0.381] 0.110 ± 0.015 [2.79 ± 0.381]
PARAMETER UNIT TYPICAL WIREWOUND FUSE RESISTOR CHARACTERISTICS
Resistance Tolerance ± % 3, 5, 10
Temperature Coefficient ppm/°C 90 - 0.1Ω thru 0.99Ω; 50 - 1Ω thru 9.9Ω; 30 - 10Ω and above
Power Rating W 1.0 standard, higher power ratings available
Dielectric Strength VAC 500
Insulation Resistance MΩ1000 minimum dry
Fusing Times S 0.001 to 1.0
Minimum Fusing Current A Approximately 4 times the continuous operating current
obtainable on some designs. Larger ratios produce better designs.
Terminal Strength lb 5 minimum
Solderability –Terminals are 60/40 electro tin plated to facilitate soldering
1.25 [31.75]
Minimum
0.020 ± 0.002
[0.508 ± 0.051]
A
B
DIMENSIONS in inches [millimeters]
TECHNICAL SPECIFICATIONS
25
Fast Acting, Molded Styles
Custom Designed For Your Application
MATERIAL SPECIFICATIONS
Element: Copper-nickel alloy or nickel-chrome alloy,
depending on resistance value
Core: Alumina ceramic
Encapsulant: Thermoset silicone mold compound
End Caps: Stainless steel
Terminals: Tinned copperweld
Part Marking: DALE, Model, Value, Tolerance, Date Code