WRF Series
Conformal Coated Wirewound Resistor
Features:
Conformal coating
Flameproof construction
Cut and formed product is available on select sizes
Contact factory for details
RoHS compliant / lead-free
Stackpole Electronics, Inc.
Resistive Product Solutions
Electrical Specifications
Type / Code
WRF 1
WRF 2
WRF 3
Power Rating
(Watts) @ 25ºC
1W
2W
3W
Maximum
Working
Voltage
√PR
√PR
√PR
Dielectric
Withstanding
Voltage (RMS)
700V
700V
700V
Resistance Temperature
Coefficient
-80 ppm/ºC ~ +900 ppm/ºC
-80 ppm/ºC ~ +900 ppm/ºC
-80 ppm/ºC ~ +900 ppm/ºC
Ohmic Range and
Tolerance
5%
0.1Ω - 33Ω
0.1Ω - 220Ω
0.1Ω - 220Ω
Mechanical Specifications
Type / Code
WRF 1
WRF 2
WRF 3
A
Body Length
0.433 max
11 max
0.630 max
16 max
0.630 max
16 max
B
Body Width
0.197 max
5 max
0.197 max
5 max
0.197 max
5 max
C
Lead Length (Bulk)
1.1 ± 0.08
28 ± 3
1.1 ± 0.08
28 ± 3
1.1 ± 0.12
28 ± 3
D
Lead Diameter
0.031 ± 0.002
0.78 ± 0.05
0.031 ± 0.002
0.78 ± 0.05
0.031 ± 0.002
0.78 ± 0.05
Units
inches
mm
inches
mm
inches
mm
Power Derating Curve
Performance Characteristics
100
Test
Rated Ambient Temperature
Overload 15 Times the Rated Wattage
Short Time Overload
Effective Soldering
Insulation Resistance
Dielectric Withstanding Volt
Load Life @ 70ºC - 1,000 hrs.
Moisture Resistance
Shock and Vibration
Solderability
Temperature Coefficient
Test Results
85ºC
Open circuit within 2 minutes
± 3% + 0.05Ω
± 2% + 0.05Ω
4
>10 MΩ
± 2% + 0.05Ω
± 5% + 0.05Ω
± 5% + 0.05Ω
± 1% + 0.05Ω
90% tin covered min.
-80 ±900 ppm/ºC
Percent Rated Power (%)
75
50
WRF 3
WRF 1, 2
25
0
50
85 100
150
200
225
250
300
Ambient Temperature (ºC)
Operating Temperature Range: -55ºC to +200ºC (WRF 1, 2)
-55ºC to +220ºC (WRF 3)
How to Order
SEI Type
Code
Nominal Resistance
Tolerance
Packaging
WRF
Type
WRF
Description
Conformal Coated WW
2
Code
1
2
3
1.1K
5%
Tolerance
5%
Values
E24
Type
All
All
Pkg Qty
1,000
2,000
A
Description
Bulk
Tape
Code
A
R
Rev Date: 9/30/2009
This specification may be changed at any time without prior notice
Please confirm technical specifications before you order and/or use.
80
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