General Purpose Cement
Coated Wirewound Resistors
WA80 Series
Welwyn Components
Cost effective
Flameproof protection
Can replace carbon comp. in many applications
Resistance values down to 0.01 ohms
Ideal for pulse handling applications
Electrical Data
WA82
Power rating at 25°c
Power rating at 70°c
Resistance range
Limiting element voltage
Isolation voltage
TC R
Resistance tolerance
Values
Thermal impedance
Ambient temperature range
°C/watt
°C
140
110
watts
watts
ohms
volts
volts
ppm/°C
%
1
.86
0R068 to 430
50
250
WA83
2.0
1.6
0R05 to 900R
50
250
<1
Ω
:350
<20R: 5, 10
E24 preferred
90
- 55 to 155
82
54
WA835
2.5
2.0
0R05 to 900R
75
250
WA84
3.0
2.5
0R01 to 2K2
100
350
>1
Ω:200
≥20R:
1, 2, 5, 10
WA85
5
4.3
0R015 to 6K8
150
500
Physical Data
Dimensions (mm) and Weight (g)
PCB
mounting
centres
10.20
12.70
18.40
20.30
22.86
Min
bend
radius
0.6
1.2
1.2
1.2
1.2
Wt
nom.
0.22
0.50
0.50
1.10
1.75
d
D
Type
WA82
WA83
WA835
WA84
WA85
L max.
6.2
9.0
12.5
14.5
16.5
D max.
2.8
3.6
4.5
(Note 1)
(Note 2)
f min.
21.20
19.80
17.80
24.55
23.55
d nom.
0.6
0.8
0.8
0.8
0.8
5.2
7.0
L
f
Note 1: 5.4 for values
≥
0R1
Note 2: 7.2 for values
≥
0R1
Construction
A high quality ceramic substrate is assembled with
interference fit end caps to which are welded the termination
wires. The resistive element is wound on the substrate and
welded to the caps. Cement protection is applied to the
resistor body before marking with indelible ink.
Terminations
Material
Strength
Hot tin dipped copper wire
The terminations meet requirements of
IEC 68.2.21.
Solderability
The terminations meet the requirements of IEC
115-1, Clause 4.17.3.2.
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
12 08
© 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
89
General Purpose Cement
Coated Wirewound Resistors
WA80 Series
Marking
WA85 resistors are legend marked with type
reference, resistance value and tolerance. In conformance
with IEC 62.
WA82, 83, 835 and 84 resistors 0R1 and above are colour
coded with 4 bands in conformance with IEC 62. Values
below 0R1 are 3 band marked, two digits and tolerance,
there is no multiplier band.
Welwyn Components
Solvent Resistance
The body protection and marking are resistant to all normal
industrial cleaning fluids suitable for printed circuits.
Flammability
The resistor coating will not burn under any condition of
applied temperature or component overload.
Performance Data
Maximum
Load at rated power: 1000 hrs at 25 or 70°c
Dry heat: 1000 hrs at 200°c
Derating from rated power at 25°c
Short term overload
Climatic
Climatic category
Long term damp Heat: 56 days
T.R.C. & Vibration
Robustness & Solder Heat
Pulse Handling
∆R%
∆R%
∆R%
∆R%
∆R%
∆R%
5.0 + .001Ω
5.0 + .001Ω
55/200/56Ω
5.0 + .001Ω
5.0 + .001Ω
5.0 + .001Ω
Data available by request
1.0
1.0
1.0
∆R%
∆R%
5.0 + .001Ω
5.0 + .001Ω
See derating curve
1.0
2.0
Typical
3.0
3.0
Care must be taken when determining clearance between the
resistor body and the P.C.B. or other components. Resistance
is measured 6mm from body.
Packaging
All resistors are supplied tape packed ready for loading onto
automatic sequencing and insertion machines. The critical
dimensions are shown in figure 2.
Component wires will not protrude beyond the outside edge
of the tapes.
All taped resistors will be supplied either on reels or in
ammopacks, depending upon quantities orderded.
WA series resistors can be supplied preformed. Contact
factory for details.
Type
b
c
WA82
52
5
WA83
52
5
WA835
52
5
WA84
67
10
WA85
63
10
% of Rated Power at 70°C
Application Notes
WA80 Series Derating Curve
130
120
110
100
90
80
70
60
50
40
30
20
10
0
20
40
60
80 100 120 140 160 180 200 220 240 260 280
Temp°C
Figure 2
c
f
1
6
b
f
2
6
Body Location f
1
– f
2
≤
1.4 mm
Standard Quantities Per Package
Type
Reel
Large ammo pack
WA82 WA83 WA835 WA84 WA85
5000
5000
2500
2500
2500
1500
1000
1000
750
700
© 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
12.08
90
General Purpose Cement
Coated Wirewound Resistors
WA80 Series
Welwyn Components
Ordering Procedure
Specify type reference, value and tolerance as shown in this example of WA82 480R 5%:
Type
Resistance value
(IEC62 code)
Tolerance
(IEC62 code)
F
G
J
1%
2%
5%
WA82
480R
J
© 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
12.08
51单片机
