UT Series
Silicone Coated Power Resistors
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Resistances from 0.005 to 260kOhms
Power Rating 0.1 to 13Watts
Resistance Tolerances to ± 0.01%
Low TCR: ± 20ppm/K Standard
MIL-R-26 / MIL-R-39007 Power Ratings
Temperature Range: -55°C to +350°C ( “V” Rating )
Non-Inductive Windings Available
SPECIFICATIONS
Specification
Tolerances
Temperature Coefficient
Value
±0.01% to ±10% ( 1% Standard )
>10W : ±20ppm/K
1W to10W : ±50ppm/K
<1W : Call Factory
-55°C to +250°C : Characteristic U
-55°C to +350°C : Characteristic V
500 VAC : UT-1 / UT-1/2A / UT-1/2 / UT-1A
1000 VAC : All Others
Centerless ground ceramic core
Tinned copper or copperweld leads
High temperature / trivalent / inorganic Silicone coating
All welded terminations
Temperature Range
Dielectric Strength
Constuction
Environmental Performance
(MIL-STD 202)
DR
Characteristic U
±0.2% + 0.05W
±1% + 0.05W
±0.2% + 0.05W
±0.2% + 0.05W
±0.2% + 0.05W
±0.2% + 0.05W
±0.1% + 0.05W
±0.1% + 0.05W
120
100
Characteristic V
±0.2% + 0.05W
±3% + 0.05W
±2% + 0.05W
±2% + 0.05W
±2% + 0.05W
±2% + 0.05W
±0.2% + 0.05W
±0.2% + 0.05W
Dielectric
Load Life
Storage
Moisture Resistance
Thermal Shock
5X Overload ( 5s )
Shock
Vibration
Power Derating Curve
Power ( % )
80
60
40
20
0
CH
AR
CH
AR
V
U
0
50
100
150
200
250
300
350
400
Ordering Information
For Non-Inductive Windings / insert the letter “N” ( i.e. UTN-5 )
Part Number - Resistance - Tolerance - TCR ( If not standard )
Example: UT-5 25kOhms 0.1%
Ambient Temperature (°C)
Willow Technologies Ltd.
Shawlands Court, Newchapel Road, Lingfield, Surrey, RH7 6BL, United Kingdom.
http://www.willow.co.uk
+ 44 (0) 1342 835234
+ 44 (0) 1342 834306
rev. 03/2006A
WILLOW [ WILLOW TECHNOLOGIES LTD ]
