b

6

6

c

≤ 1.4 mm

Marking

WA85 and 87 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.

General Purpose Cement

Coated Wirewound Resistors

WA80 Series

Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: info@welwyn-tt.com · Website: www.welwyn-tt.com

90

Issue D · 08.04

Welwyn Components

Maximum

Typical

Load at rated power: 1000 hrs at 25 or 70°c

∆R%

5.0 + .001

Ω

3.0

Dry heat: 1000 hrs at 200°c

∆R%

5.0 + .001

Ω

3.0

Derating from rated power at 25°c

See derating curve

Short term overload

∆R%

5.0 + .001

Ω

1.0

Climatic

∆R%

5.0 + .001

Ω

2.0

Climatic category

∆R%

55/200/56

Ω

Long term damp Heat: 56 days

∆R%

5.0 + .001

Ω

1.0

T.R.C. & Vibration

∆R%

5.0 + .001

Ω

1.0

Robustness & Solder Heat

∆R%

5.0 + .001

Ω

1.0

Pulse Handling

Data available by request

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

20

40

60

80 100 120 140 160 180 200 220 240 260 280

130

120

110

100

90

80

70

60

50

40

30

20

10

0

Temp

°C

WA80 Series Derating Curve

Type

WA82 WA83 WA835 WA84 WA85 WA87

Reel

5000

2500

2500

1000

750

700

Large ammo pack

5000

2500

1500

1000

700

n/a

Standard Quantities Per Package

Application Notes

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.

Figure 2

Type

WA82

WA83

WA835

WA84

WA85

WA87

b

525252676385

c

5

5

5

10

10

10

WA80_D.qxd

8/6/04

10:58 AM

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