Ultra Low Profile

Power Resistors

WDBR Series

•

Ultra low profile thick-film on steel

•

500W to 7kW peak power

•

Single fixing heatsink mountable

•

Ideal for dynamic braking, inrush limit and snubber circuits

•

Choice of flying lead, push-on or solder terminations

•

Low inductance design

•

High isolation, even after failsafe overload fusing

•

RoHS compliant, non-flammable construction

Electrical Data

WDBR1/2

WDBR1

WDBR2

WDBR3

WDBR5

WDBR7

Resistance range

ohms

22, 47, 100

12, 22, 47, 100, 150

47, 100, 150

Resistance tolerance

%

10

Pulse power rating

1

kW

0.5

1.5

2.0

3.5

5.0

7.0

Power rating on heatsink

2

W

160

180

200

260

270

280

4

Power rating on fan-cooled heatsink

3

W

300

700

780

900

1000

1490

4

TCR

ppm/°C

+500 to +600

Maximum element temperature

°C

365

Dielectric withstand

V (dc/ac peak)

2500

Inductance (typical)

μH

<3

<4

<5

<6

Notes:

1.

For details of pulse condition see Fig. 1 in Performance Data.

2.

Mounted on a 0.53°C/W heatsink with no forced air cooling, air temperature 25°C.

3.

Mounted on a 0.53°C/W heatsink with 5m/s forced air cooling, air temperature 25°C.

4.

Limited by the solder type; the rating can be improved for non-standard parts by using HMP solder.

Physical Data

Dimensions in mm, weight without terminations in g

WDBR1/2

31.9

28.1

2.2

7.5

3.1

4.3

6.5

WDBR1

49.3

35.9

3.2

3.2

11.2

6.2

12.6

WDBR2

61

40.6

4.7

13.0

5.8

17.1

WDBR3

101.6

70

13.5

22.0

10.2

50.8

WDBR5

122

70

0.9

14.0

23.8

7.4

60.7

WDBR7

152.4

101.6

1.5

5.3

15.0

51.3

9.2

181.8

Construction

A high integrity dielectric layer is applied to a machined

stainless steel substrate. Thick-film conductor and resistor

patterns are printed and fired, then protected with a high

temperature overglaze. The termination pads are tinned with

Pb-free solder and optional terminals or leads are soldered on.

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 test data and is considered accurate at time of print.

©Welwyn Components Limited

Welwyn Electronics Park, Bedlington, Northumberland, NE22 7AA, England. Tel: 01670 822181 Fax: 01670 829465 Web: www.welwyn-tt.com

W

L

c

b

a

Substrate thickness = t

Fixing hole is located centrally

D