Ultra Low Profile
Power Resistors
WDBR Series
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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
Resistance range
ohms
Resistance tolerance
%
1
Pulse power rating
kW
2
Power rating on heatsink
W
3
Power rating on fan-cooled heatsink
W
TCR
ppm/°C
Maximum element temperature
°C
Dielectric withstand
V (dc/ac peak)
Inductance (typical)
μH
Notes:
1.
2.
3.
4.
WDBR1/2
22, 47, 100
0.5
160
300
WDBR1
1.5
180
700
<3
WDBR2 WDBR3
12, 22, 47, 100, 150
10
2.0
3.5
200
260
780
900
+500 to +600
365
2500
<4
WDBR5
WDBR7
47, 100, 150
7.0
280
4
4
1490
5.0
270
1000
<5
<6
For details of pulse condition see Fig. 1 in Performance Data.
Mounted on a 0.53°C/W heatsink with no forced air cooling, air temperature 25°C.
Mounted on a 0.53°C/W heatsink with 5m/s forced air cooling, air temperature 25°C.
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
L
±0.1
W
±0.1
t
±0.1
ØD nom a nom b nom c nom Wt. nom
WDBR1/2
WDBR1
WDBR2
WDBR3
WDBR5
WDBR7
31.9
49.3
61
101.6
122
152.4
28.1
35.9
40.6
70
5.3
70
101.6
1.5
14.0
15.0
23.8
51.3
7.4
9.2
60.7
181.8
Substrate thickness = t
Fixing hole is located centrally
D
c
a
2.2
3.2
0.9
7.5
3.2
4.7
13.5
3.1
11.2
13.0
22.0
4.3
6.2
5.8
10.2
6.5
12.6
17.1
50.8
L
W
b
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
WELWYN [ WELWYN COMPONENTS LIMITED ]
