These resistors meet or exceed the requirements of MIL-PRF-18546 G specifications.
Fixed power wirewound resistors aluminium housed 25W
Electrical Specifications
– Ohmic values
Series E24. For out of range or not standard ohmic values, consult UPE Technical Department.
– Tolerance
Standard 5%. Available on request up to 1%.
– Temperature coefficient
±30 ppm R > 20 Ohm
±50 ppm 1 Ohm < R < 20 Ohm
±100 ppm 0.1 Ohm < R < 1 Ohm
– Dielectric strength
2500 Vac for RB25
– Insulation resistance
10000 MOhm minimum
1000 MOhm after moisture test
– Overload
5s at 5 times rated power
– Non inductive
Models of equivalent physical and electrical specifications are also available with non inductive Ayrton-Perry winding
Mechanical Specifications
– Terminal strength
10 lb. pull test; 3 Nm x RB100 and 4 Nm x RB250 max torque
– Solderability
Satisfactory when tested in accordance with method 208 of MIL-STD-202. The use of high temperature solder is recommended when resistors work near the maximum specified ratings
Materials
– Core
Ceramic steatite or alumina centerless ground
– Resistive Element
Copper-nickel alloy or nickel-chrome alloy with specific temperature coefficient
– End caps
Stainless steel
– Encapsulant
High temperature thermosetting compound
– Housing
Aluminium with hard anodic finish
– Standard terminals
Copperweld
Derating
ATE RB resistors have and operative temperature range from -55°C to +250°C
Derating is required for reduced chassis area and for high ambient temperature