WSM Datasheet, PDF (1/2 Pages) Welwyn Components Limited – Moulded Surface Mount Wirewound Resistors

Moulded Surface Mount
Wirewound Resistors
WSM Series
• Ideal for automatic pick and place
• Direct replacement for Axial resistors
• All welded construction
Welwyn Components
Electrical Data
Power rating at 70°C
Resistance range
Limiting element voltage
TCR
watts
ohms
volts
ppm/°C
Resistance tolerance
Standard values
Ambient temperature range
*Note 5% or 10% preferred below 0.1 ohms
Physical Data
Dimensions (mm)
Type
L max
WSM1
7.9
WSM2
12
WSM3
18
I Nom
2.54
3.1
3.1
W Max
7
10.5
16
w Max
4.2
6.6
7
%
°C
H Max
3.94
5.5
6.5
WSM1
1
0R01 to 1K
< 1 Ω : 100
≥ 1 Ω : 20
L
WSM2
2
0R01 to 2K
100
< 1 Ω : 100
≥ 1 Ω : 20
*1, 2, 5, 10
E24 preferred
-55 to 155
WSM3
3
0R01 to 3K
≤.03 Ω 700 ≤0.1 Ω : 200
≤10R 100 >10R 20
W
I
w
H
Recommended Pad Sizes
Type
A
B
C
D
WSM1
2.9
2.6
2.8
8.1
WSM2
3.4
4.0
6
14
WSM3
3.4
4.5
11
20
B
C
A
D
Construction
A high purity ceramic substrate is assembled with interference
fit end caps to which are welded the terminations. The
resistive element is wound on the substrate and welded to
the caps. The unit is then moulded.
Flammability
The resistor coating is a flame retardant epoxy to UL 94.
Marking
WSM resistors are legend marked with type value and
tolerance.
WSM1 Resistors are marked with value and tolerance.
Solvent Resistance
The body protection and marking are resistant to all normal
industrial cleaning solvents suitable for printed circuits.
General Note
Welwyn Components reserves the right to make changes in product specification without notice or liability.
All information is subject to Welwyn’s own data and is considered accurate at time of going to print.
© Welwyn Components Limited · Bedlington, Northumberland NE22 7AA, UK
Telephone: [phone] · Facsimile: [phone] · Email: [e-mail] · Website: www.welwyn-tt.com
A subsidiary of
TT electronics plc
Issue C · 04.03
45