Ultra Precision Bulk Metal
Film Resistors
4800 series
Welwyn Components
Physical Data
Dimensions (mm) & Weight (g)
Type
4802
4812
4804
4805
4832
L max
8.9
7.5
15.2
22.6
9.7
H max
10.2
8
13.2
13.2
5.4
W max
3.8
2.5
3.8
3.8
9.7
T min
30
30
30
30
30
d nom
0.6
0.6
0.6
0.6
0.6
S nom
5.1
5.1
10.2
17.8
1.5
Wt. nom
1
0.6
T
H
4802/12/04/05
L
W
d dia
S
4832
1.5
2
1.1
d
H
L
T
W
S
Construction
The resistor element is an etched bulk metal foil, bonded to
an alumina substrate. Connections to the foil are made by
copper wires welded to the foil to minimise thermal e.m.f.
Before encapsulation, the resistor element is coated with
silicone rubber to isolate the element from mechanical stress
which would adversely affect the carefully balanced
construction and result in poor resistance/temperature
characteristics.
Terminations
Material
Strength
Solderability
Solder coated copper wire
The terminations meet the requirements of
IEC 68.2.21.
The terminations meet the requirements of
IEC 115-1, Clause 4.17.3.2.
Marking
Type reference, resistance value, tolerance and date code are
legend marked. The resistance value conforms to IEC 62.
Solvent Resistance
The protection will withstand all normal industrial solvents
suitable for cleaning printed circuit boards.
Performance Data
Actual
Load at commercial rating: 1000 hours at 70°C
Dry heat: 1000 hours at 155°C
Shelf life: 12 months at room temperature
Derating from rated power at 70°C
Short term overload
Climatic category
Climatic
Long term damp heat
Temperature rapid change
Resistance to solder heat
Vibration and bump
Noise. (in a decade of frequency)
Voltage coefficient of resistance
Insulation Resistance
Inductance
Capacitance
∆R%
∆R%
∆R%
∆R%
∆R%
∆R%
∆R%
∆R%
∆R%
µV/V
ppm/V
ohms
µH
pF
Maximum
0.05
0.05
Zero at 155°C
0.01
55/155/56
0.05
0.05
0.01
0.01
0.01
Below level of
practicable measurement
>1000M
0.2
1
0.08
0.5
0.03
0.03
0.005
0.005
0.005
0.005
Typical
0.02
0.02
0.0025
Packaging
All components are supplied loose packed in either plastic bags
or panel boxes. Quantity per box will depend on resistor size.
© Welwyn Components Limited
Bedlington, Northumberland NE22 7AA, UK
Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: info@welwyn-tt.com · Website: www.welwyn-tt.com
Issue B · 03.02
187
WELWYN [ WELWYN COMPONENTS LIMITED ]
