WA80_D.qxd
8/6/04
10:58 AM
Page 1
General Purpose Cement
Coated Wirewound Resistors
Welwyn Components
WA80 Series
• 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
WA83
WA835
WA84
WA85
WA87
Power rating at 25°c
watts
1
2.0
2.5
3.0
5
7
Power rating at 70°c
watts
.86
1.6
2.0
2.5
4.3
6
Resistance range
ohms
0R068 to 430
0R05 to 900R
0R05 to 900R
0R01 to 2K2
0R015 to 6K8
0R15 to 10K
volts
50
50
75
100
150
150
volts
250
250
250
350
500
700
Limiting element voltage
Isolation voltage
TCR
ppm/°C
Resistance tolerance
<1Ω:350
%
>1Ω:200
<20R: 5, 10
Values
≥20R: 1, 2, 5, 10
E24 preferred
Thermal impedance
°C/watt
Ambient temperature range
140
110
82
°C
90
54
35
- 55 to 155
Physical Data
Dimensions (mm) and Weight (g)
L max.
D max.
f min.
d nom.
PCB
mounting
centres
WA82
6.2
2.8
21.20
0.6
10.20
0.6
WA83
9.0
3.6
19.80
0.8
12.70
1.2
0.50
WA835
12.5
4.5
17.80
0.8
18.40
1.2
0.50
WA84
14.5
5.2
24.55
0.8
20.30
1.2
1.10
WA85
16.5
7.0
23.55
0.8
22.86
1.2
1.75
WA87
25.0
8.8
28.30
0.8
31.40
1.2
4.40
Type
Min
bend
radius
Wt
nom.
0.22
d
D
L
f
Construction
Terminations
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.
Material
Solder-coated copper wire on 82, 83, 835, 84,
and 85, solder coated cooper clad steel on 87.
Strength
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
© 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 D · 08.04
89
