Flameproof Power
Metal Film Resistors
FA Series
Construction
The resistance element is a precisely controlled thin film of
metal alloy on a high purity ceramic core, protected by a
cement coating applied so that terminations remain
completely clear.
This permits a well defined body length, (clean lead to clean
lead dimension L).
Welwyn Components
Marking
Resistors are colour coded with 4 bands.
IEC 62 colours are used.
Solvent Resistance
The body protection and marking are resistant to all normal
industrial cleaning solvents suitable for printed circuits.
Terminations
Material
Strength
Solder-coated copper wire.
The terminations meet the requirements of
IEC 68.2.21
Flammability
The resistors will not burn or emit incandescent particles
under any condition of applied temperature or power
overload.
Solderability
The terminations meet the requirements of
IEC 115-1, Clause 4.17.3.2
Performance Data
CECC 40101-019/40101-024
Requirements
Load at commercial rating: 1000 hrs at 70°C
Load at CECC rating: 1000 hrs at 70°C
Load at 35% rated power: 1000 hrs at 125°C
Dry heat: 1000 hours at 155°C
Shelf life: 12 months at room temperature
Derating
Short term overload
Climatic
Climatic category
Long term damp heat
Temperature rapid change
Resistance to solder heat
Vibration and bump
∆R
%
∆R
%
∆R
%
∆R
%
∆R
%
∆R
%
∆R
%
∆R
%
∆R
%
∆R
%
∆R
%
not specified
2
2
not specified
not specified
35% of rated power at 125°C
0.5
2
55/125/56
2
0.5
0.5
0.5
2
0.25
0.25
0.1
Actual Performance
Maximum
3
2
1
1
0.5
zero at 235°C
0.2
0.5
55/125/56
0.5
0.05
0.07
0.01
0.02
0.5
Typical
1
1
0.7
0.7
0.5
Application Notes
1. If the resistors are to dissipate full rated power, it is
recommended that the terminations should not be
soldered closer than 4mm from the body.
2. Due to operating temperature limitations imposed by some
pcb materials, derating may be necessary. An estimate of
the temperature rise to be expected can be calculated using
the thermal impedance figures given under Electrical Data.
Packaging
All FA Series resistors are normally supplied tape packed ready
for loading onto automatic sequencing and insertion
machines.
Component wires will not protrude beyond the outside edge
of the tapes.
Alternative packaging available by request.
Lead Formed resistors can also be supplied. Standard options
of Lancet, Radial and Goalpost forming are shown in Lead
Form Information section.
Standard Quantities Per Package
Type
Large ammo pack
FA025
5000
FA05
2500
FA1
1000
FA94
1000
c
Type
FA025/FA05
FA1
FA94
b
52
67
77
c
5
10
10
f
1
6
b
f
2
6
Body Location f
1
– f
2
≤
1.4 mm
© 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
146
Issue B · 03.02
WELWYN [ WELWYN COMPONENTS LIMITED ]
