Metal Film Resistors
Welwyn Components
WRN Series
•
Conforms to MIL-R-10509
•
Resistance range: 1 ohm to 1M ohms
•
High reliability
Electrical Data
WRN55
C
Power rating
Resistance range
Limiting element voltage
TCR
Resistance tolerance
Ambient temperature range
watts
ohms
volts
ppm/°C
%
°C
50
1
-55 to 155
0.1 @ 125°C
1R0 - 1M
350
100
D
0.125 @ 70°C
Physical Data
Dimensions (mm)
PCB
Type
WRN55
L Max
6.2
D Max
2.5
f min
52.00 ±1
63.50 ±1
d nom
0.6
mounting
centres
10.2
Min.
bend
radius
0.6
d
D
L
f
Construction
The resistance element is a precisely controlled thin film of
metal alloy sputtered on to a high purity ceramic core,
protected by a moisture-resistant, high dielectric strength
coating applied so that terminations remain completely clear.
This permits a well defined body length, (clean lead to clean
lead dimension L).
Marking
Components are legend marked with style, charcatestc,
resistance value and resistance tolerance.
RN55D
1003F
RN55
D
Characteristic
1003
Resistance
value
F
Resistance
value
Style
Terminations
Material
Strength
Solder-coated copper wire.
The terminations meet the requirements of
IEC 68.2.21 and MIL-R-10509.
Solvent Resistance
The body protection and marking are resistant to all normal
industrial cleaning solvents for printed circuits.
Solderability
The terminations meet the requirements of
IEC 115-1, Clause 4.17.3.2 and MIL-R-10509.
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.
A subsidiary of
TT electronics plc
Issue B · 03.02
© 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
140
Metal Film Resistors
WRN Series
Welwyn Components
Performance Data
Tested in accordance with Mil-R-10509
C
Thermal Shock
Low temperature operation
Terminal strength
Short term overload
Dielectric withstanding voltage
Effect of solder heat
Load life
Shock
Moisture resistance
Vibration
∆R%
∆R%
∆R%
∆R%
∆R%
∆R%
∆R%
∆R%
∆R%
∆R%
0.25
0.25
0.2
0.25
0.25
0.25
0.5
0.25
0.5
0.25
Requirements
D
0.5
0.5
0.5
0.5
0.5
0.5
1
0.5
1.5
0.5
0.2
0.1
0.15
0.2
0.2
0.1
0.25
0.1
0.5
0.1
Typical
Tested to CECC 40101-019
Shelf life: 12 months at room temperature
Long term damp heat
Temperature rapid change
Insulation resistance
∆R%
∆R%
∆R%
ohms
Maximum
0.1
0.5
0.25
>1G
Figure 2
5
6
1) 52.00
±
1
2) 63.50
±
1
6
Standard Quantities Per Package
Type
Large ammo pack
WRN55
5000
© 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
141
Metal Film Resistors
WRN Series
Graph 1
Maximum peak pulse power
as a function of puse duration (ti)
100
Peak Power (W)
10
10000
Peak Power (V)
1000
100
10
1
0.1
Welwyn Components
Graph 2
Maximum peak pulse voltage
as a function of puse duration (ti)
1
WRN55
0.1
0.1
WRN55
1
10
ti (s)
100
1000
10000
1
10
ti (s)
100
1000
10000
Graph 3
Maximum peak pulse power
individual pulses
1000
Peak Power (W)
100
10
WRN55
1
0.1
1
10
ti (s)
100
1000
10000
Test Method for Graphs 1 and 2
The resistor is subject ot 10,000 pulses as shown in figure 1.
Maximum resistance change due to test will not exceed 1%.
Maximum pulse voltages are detailed in graph 2 above. For
any combination of power and pulse length (ti) tp is
determined by the need to ensure that the average power
does not exceed the rated power.
tp =
Applied Pulse Power
Rated Power
x ti
Figure 1
Voltage
(V)
ti
Time (secs)
tp
Test Method for Graph 3
The resistor is subject to 1000 impulses of rectangular shape
applied at one minute intervals. The limit of acceptance was a
shift in resistance of less than 1% from the initial value. The
power applied was subject to the restrictions of the maximum
permissible impulse voltage graph.
© 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
142
Issue B · 03.02
