Fusible Metal Film
Resistors
FA8025 series
Welwyn Components
Performance Data
Maximum
Load: 1000 hours at 70˚C
Shelf life: 12 months at room temperature
Derating from rated power at 70˚ C
Temperature rapid change
Resistance to solder heat
R%
R%
0.5
0.5
R%
R%
2
0.5
zero at 155˚ C
0.2
0.2
Typical
0.5
0.2
Predicting Fusing Time For Defined Power Input
Graphs 1 to 3.
Fusible Resistors: Typical Fusing Window
Graph 4.
Normal rated
power
Fusing:
After fusing the final resistance value will be 50 times the
initial value. See graph for explanation of fusing curves.
Graph 1
Fusing
Time
(secs)
Min power for
guaranteed
fusing
Max fusing time
Min fusing time
Initial Power (watts)
Max sale
fusing
power
Packaging
The preferred method of packaging is taped and ammo
packed, see figure 1 for critical dimensions.
Alternative packaging is available by special request.
Graph 2
Lead Formed resistors can also be supplied. Standard options
of Lancet, Radial and Goalpost forming are shown in Lead
Form Information section.
Figure 1
c
f
1
Graph 3
6
b
Body Location f
1
– f
2
f
2
6
1.4 mm
Type
b
c
FA82*
26
5
FA82/FA83
52
5
FA84
67
10
Standard Quantities Per Package
Type
Ammopack
FA8225
5000
FA8325
2500
FA8425
1000
© 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
154
Issue C · 03.02
B 01.07
WELWYN [ WELWYN COMPONENTS LIMITED ]
