Power Resistors
NPR NPS
2-T220 T221
NHR NHS
2-T220 T221
SPECIFICATIONS
(continued)
Temperature Coefficient
100ppm/°C
7000
∆R/R (ppm)
50ppm/°C
2000
-3000
-8000
-50
-25
0
Temperature (°C)
25
50
75
100
125
120
Derating
Power Rating Notes -
Power ( % from
nominal power)
100
80
60
40
20
0
25
50
85
100
115
130
145
155
Temperature of the backplate (°C)
The NPR / NHR Series Resistors must be attached to a suitable
heatsink. The maximum internal resistor temperature is 155°C.
To specify an appropriate heatsink use the following formula :
R
qH
= T
MAX
- ( P x R
qR
) - T
A
P
Where:
R
qH
= Thermal Resistance of Heatsink ( K/W )
R
qR
= Thermal Resistance of Resistor ( K/W )
T
MAX
= Maximum Temperature of Resistor
T
A
= Ambient Temperature of Heatsink ( °C )
P = Power Through Resistor ( W )
Dimensions
NPS / NHS 2-T220
Dimension
A
B
C
D
E
F
G
H
I
J
K
mm
12.70
10.16
0.76
5.08
4.00
1.20
14.60
15.00
17.33
0.40
1.85
tol.
(±mm)
0.2
0.2
0.1
0.1
0.1
0.1
0.2
0.2
0.2
0.1
0.1
inches
0.50
0.40
0.03
0.20
0.16
0.05
0.57
0.59
0.68
0.02
0.07
tol.
(±inches)
0.008
0.008
0.004
0.004
0.004
0.004
0.008
0.008
0.008
0.004
0.004
Dimension
A
B
C
D
E
F
mm
12.10
11.16
18.33
5.08
1.76
3.20
inches
0.476
0.439
0.722
0.200
0.069
0.126
Riedon Inc.
300 Cypress Avenue
Alhambra CA 91801
(626) 284-9901
(626) 284-1704
Page 81
07/13
RIEDON [ RIEDON POWERTRON ]
