Vitreous Enamelled Heavy

Duty Tapewound Resistors

U400 Series

• Very low resistance values

• Choice of terminations and mounting styles

• High overload capability

Dimensions (mm)

Type

A

B

C

D

E

F

G

H

J

max

max

nom

nom

nom

max

max

max

U412

53

28

13

5.7

6.8

26.5

M4

85

39

U413

116

28

13

5.7

6.8

26.5

M4

150

39

U414

102

36

19

7

98

32

M6

134

43

U415

152

36

19

7

9.8

32

M6

184

43

U416

216

36

19

7

98

32

M6

248

43

U417

267

36

19

7

9.8

32

M6

299

43

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.

© 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

127

Physical Data

Issue D · 08.04

A subsidiary of

TT electronics plc

Welwyn Components

General Information

The U400 Series of resistors is particularly suitable for

overload applications, due to the large energy absorption

capability of the heavy tape element and careful matching of

tube and enamel thermal characteristics.

The Welwyn range is based on six sizes of tube, each of

which has a recommended dissipation which limits operating

surface temperature to a maximum of 350°C.

The resistors may be fitted with tapping bands as required;

these may also be used as adjusting bands.

Each style is available with the following choice of

terminations:-

a) Lugs for soldered or screwed connection Style U

b) Pigtails for flexible connection Style UP

c) Ferrules, permitting connection via spring mounting clips

Styles UC and UCB

The U400 Series is designed for use with Welwyn type MD40

mounting brackets. and the UC400 Series with spring

mounting clips

See figs 2 to 6 for illustrations

Electrical Data

U412

U413

U414

U415

U416

U417

Power rating at 20°C*

watts

30

60

125

140

275

375

Resistance range

ohms

0R09 to 2R25

0R27 to 6R8

0R28 to 7R2

0R48 to 12R4

0R76 to 19R0

0R96 to 39R0

TCR range

(-55 to +200°C).

ppm/°C

Typically: +75 Maximum: +200

Resistance tolerance

%

10

Values

Any value within the specified resistance range

Ambient temperature range

°C

-55 to +350

*Mounted horizontally with unobstructed bore.

U400_D.qxd

8/9/04

4:55 PM

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