Ultra Low Profile Power Resistors
WDBR-UL Series
Features:
•
•
•
•
•
•
•
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Ultra low profile thick-film on steel
Up to 7kW peak power
Single fixing heatsink mountable
Ideal for dynamic braking, inrush limit and snubber circuits
Choice of flying lead or solder terminaꢀons
Low inductance design
High isolaꢀon, even aꢂer failsafe overload fusing
RoHS compliant, non-flammable construcꢀon
UL508 cerꢀfied—UL file E238661
All Pb-free parts comply with EU Direcꢀve 2011/65/EU amended by (EU) 2015/863 (RoHS3)
Electrical Data
WDBR1UL
WDBR2UL
WDBR3UL
WDBR5UL
WDBR7UL
Resistance range 5
Ω
12, 15, 20, 22, 25, 47, 50, 100, 150
10
Resistance tolerance
Pulse peak power rating 1
Power rating on heatsink 2
Power rating on fan cooled heatsink 3
TCR
%
kW
1.5
170
660
2
3.5
240
5
7
W
190
740
250
950
260
1410
W
850
ppm/°C
<+600
450
Maximum element temperature
Ambient temperature range (heatsink)
Dielectric withstand 4
Inductance
°C
°C
V (dc/ac pk)
µH
-55 to +200
2500
<4
<3
<5
<6
Notes:
1. For details of pulse condiꢀon 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. Based on 100% producꢀon test, duraꢀon 2s minimum.
5. Other ohmic values upon request
Physical Data
Dimensions in mm and weight without terminations in g
t = substrate thickness.
L
W
t
ØD
a
b
c
d
Wt.
Type
±0.1
±0.1
±0.1 nom
nom
nom
nom
min
nom
d = clearance between
exposed conductor
and exposed steel
substrate.
WDBR1UL 49.3
WDBR2UL 61
WDBR3UL 101.6
WDBR5UL 122
35.9
3.2
4.2
5.5
17.6
19.7
4.2
5.5
2.9
4.5
7.5
7.5
12.6
17.1
50.8
40.6 0.9
70
14.5 24.8 10.1
15.3 27 8.6
5.3
The fixing hole is
centrally located.
70
101.2
181.8
1.5
WDBR7UL 152.4 101.6
39.3 10.7 11.8 10.5
Construcꢀon
Construcꢀon Cross Secꢀon
A high integrity dielectric layer is applied to
a machined stainless-steel substrate. Thick-
film conductor and resistor paꢁerns are
printed and fired, then protected with a high
temperature overglaze. The terminaꢀon
pads are ꢀnned with solder and opꢀonal
leads are soldered on.
General Note
BI Technologies IRC Welwyn
TT Electronics reserves the right to make changes in product specificaꢀon without noꢀce or liability.
All informaꢀon is subject to TT Electronics’ own data and is considered accurate at ꢀme of going to print.
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05.23
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