NPR NPS 2-T220 T221
NHR NHS 2-T220 T221
Power Resistors
SPECIFICATIONS (continued)
Temperature Coefficient
100ppm/°C
50ppm/°C
7000
2000
-3000
-8000
-50
-25
0
25
50
75
100
125
Temperature (°C)
Derating Power Rating Notes -
120
100
80
60
40
20
0
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 :
RθH = TMAX - ( P x RθR ) - TA
P
Where: RθH = Thermal Resistance of Heatsink ( K/W )
RθR = Thermal Resistance of Resistor ( K/W )
TMAX = Maximum Temperature of Resistor
TA = Ambient Temperature of Heatsink ( °C )
P = Power Through Resistor ( W )
25
50
85
100
115
130
145
155
Temperature of the backplate (°C)
Dimensions
NPS / NHS 2-T220
tol.
tol.
Dimension
mm
12.70
10.16
0.76
(±mm)
inches
(±inches)
0.008
0.008
0.004
0.004
0.004
0.004
0.008
0.008
0.008
0.004
0.004
Dimension
mm
12.10
11.16
18.33
5.08
inches
0.476
0.439
0.722
0.200
0.069
0.126
A
B
C
D
E
F
G
H
I
0.2
0.2
0.1
0.1
0.1
0.1
0.2
0.2
0.2
0.1
0.1
0.50
0.40
0.03
0.20
0.16
0.05
0.57
0.59
0.68
0.02
0.07
A
B
C
D
E
F
5.08
4.00
1.76
1.20
3.20
14.60
15.00
17.33
0.40
J
K
1.85
Riedon Inc.
07/13
300 Cypress Avenue
Alhambra CA 91801
www.riedon.com
(626) 284-9901
(626) 284-1704
Page 81
RIEDON [ RIEDON POWERTRON ]
