FN Datasheet, PDF (1/2 Pages) Welwyn Components Limited – Fusible Nickel Film Resistors

Fusible Nickel
Film Resistors
FN Series
• Predictable fusing characteristics
• ^{Constant current fusing}
• ^Flameproof
Welwyn Components
Electrical Data
Power rating at 70°C
Resistance range
TCR
Resistance tolerance*
Standard values
Thermal impedance
Ambient temperature range
* Below 1R, 10 and 20% only.
watts
ohms
ppm/°C
%
°C/watt
°C
Physical Data
Dimensions (mm) & Weight (g)
PCB
Min.
mounting bend Wt.
Type
L Max D Max f min d nom centres radius nom
FN4
6.2
2.5
21.0
0.6
10.2
0.6
0.3
FN4
0.4
0R1 to 20R
See Figure 1
5, 10, 20
E24 preferred
215
-55 to 155
d
D
L
f
Construction
The nickel film is deposited on a high purity ceramic rod. End
caps are force fitted and termination wires welded to the
caps. The resistive film is adjusted to the required value by a
helical cut; finally the flame retardant lacquer protection is
applied to the resistor body and the resistor is marked with an
indelible ink.
Terminations
Material
Solder-coated copper wire.
Strength
The terminations meet the requirements of
IEC 68.2.21
Solderability The terminations meet the requirements of
IEC 115-1, Clause 4.17.3.2
Marking
Resistors are colour coded with five bands. Four of the bands
are used to indicate value and tolerance, with IEC 62 colours
being used. A fifth black band denotes constant current
fusibility.
Solvent Resistance
The body protection and marking are resistant to all normal
industrial cleaning solvents suitable for printed circuits.
Flammability
The resistors will not burn or emit encandescent particles
under any condition of applied temperature or power
overload.
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
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A subsidiary of
TT electronics plc
Issue B · 03.02