Thick film power resistors 250 W and 500 W
Vishay Sfernice RPS series thick film non-inductive resistors for heatsink mounting
Particularly suited to severe impulse applications
Easy mounting and optimised housing cut-outs
Low thermal radiation
Power Dissipation 70°C on radiators:
RPS 250DH: 250W
RPS 500DH: 500W
Tolerance:
±5%
Temperature coefficient:
±250 ppm/°C (R
±150 ppm/°C (R1 Ω)
Max. service voltage:
5 kV RMS
Thermal resistance:
RPS 250DH: 0.22°C/W
RPS 500DH: 0.11°C/W
Dielectric rigidity:
14 kV RMS
Operating temperature:
–55°C to +125°C
Key Characteristics
Overload duration
RCH25
RCH50
BDS100
BDS250
1 sec.
375W
750W
200W
1500W
2 sec.
300W
600W
150W
1250W
5 sec.
125W
250W
125W
1000W
10 sec.
75W
150W
100W
750W
For each degree the ambient temperature is raised above 25°C, there is a reduction by 1% of the permitted overload.
The key characteristics table is only applicable to resistors suitably mounted on a heatsink with a thermal resistance of 1°C/W for 25 and 50W ratings, 0.7°C/W for 100W and 0.28°C/W for 250W ratings.
This data is only valid when thermal grease is used and the resistor is correctly tightened by mounting screws.
Tightening Torque
RCH25
RCH50
BDS100
BDS250
0.7Nm
1Nm
2Nm
2Nm
Dimensions
Sfernice series
RCH 5
RCH 10
RCH 25
RCH 50
L
16.6
19
28
50
W
9
11
14
15.5
H
16.4
20.6
27.5
29.4
P
10.2
12.7
18.3
33
F
11.3
14.3
18.3
39.7
T
12.5
15.9
19.8
21.4
S
5.3
5
7.7
8
ØD
2.4
2.4
3.2
3.2
M2
M2
M3
M3
