Vitreous Enamelled

Wirewound Resistors

W20 Series

for protection circuits

Dimensions (mm) and Weight (g)

Type

L max

D max

f min

d nom

Wt.nom

W21

12.7

5.6

22.75

0.8

1

W215

22.0

7.0

23.1

0.8

2

W22

22.0

8.0

23.1

0.8

2

W23

38.0

8.0

-

0.8

3.5

W24

53.5

8.0

-

0.8

5

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.

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

Commercial

W21

W215

W22

W23

W24

Power rating at 25°C

watts

3.0

5.0

7.0

10.0

14.0

Resistance range at

1% tolerance

ohms

1R to 10K

1R to 15K

1R to 22K

1R to 60K

1R to 100K

2% tolerance

ohms

0R5 to 10K

0R5 to 15K

0R5 to 22K

1R to 60K

1R to 100K

5% tolerance

ohms

0R1 to 10K

0R1 to 15K

0R1 to 22K 0R15 to 60K 0R2 to 100K

TCR (-55° to 200°C)

pp/°C

Typically: <+

-75

Maximum: +

-200

Approved BS CECC 40-201-002

Style

JB

HB

KB

LB

MB

Power rating at 25°C

watts

2.9

5.0

7.0

10.0

14.0

Power rating at 70°C

watts

2.5

4.3

6.0

9.0

12.0

Resistance range at

1% tolerance

ohms

1R to 10K

1R to 15K

1R to 20K

1R to 56K

1R to 100K

2% tolerance

ohms

0R5 to 10K

0R5 to 15K

0R5 to 20K

1R to 56K

1R to 100K

5% tolerance

ohms

0R1 to 10K

0R1 to 15K

0R1 to 20K 0R15 to 56K 0R2 to 100K

TCR (-55° to 200°C)

ppm/°C

≥5 ohms < 10 ohms: ±400

≥10 ohms: ±200

Applicable to commercial and approved ranges

Limiting element voltage

volts

100

160

200

500

750

Standard values

E24 preferred. Other values to special order

Thermal impedance

°C/watt

88

58

44

29

22

Ambient temperature range

°C

-55 to 200

Electrical Data

Physical Data

Issue C · 04.03

A subsidiary of

TT electronics plc

Welwyn Components

85

L

D

f

d

Construction

A high purity 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; the vitreous enamel protective coating is then applied.

Terminations

Material

Copper clad steel wire, nickel plated and solder-coated.

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.

Length

W23’s and W24’s are not supplied on tape. Minimum lead length is 30 mm.

Marking

The resistors are legend marked with type reference, resistance value and tolerance. Values are

marked in accordance with IEC 62.

0

5

10

15

20

W21

W215

W22

W24

W23

400

300

200

100

0

Dissipation – Watts

W20_C.qxd

28/4/03

10:19 am

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