MIL-PRF-94 Resistors, Variable, Composition General Specification ForThis specification covers the variable resistors having a composition resistance element shaped in an arc, and a contact bearing uniformly thereon, so that a change in resistance is produced between the terminal of the contact and the terminal of either end of the resistance element when the operating shaft is turned. These resistors are capable of full load operation \(where maximum resistance is engaged\) at a maximum ambient temperature of 70 degrees C and are capable for continuous operation when properly derated, at a maximum temperature of 120 degrees C \(see 6.9\).

Pages 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - 10

MIL-PRF-94G

3.4.2 Rotation. The total mechanical rotation and electrical rotation shall be defined on figure 2. The electrical

rotation of resistors with switches shall be equal to the rotation from stop at the end opposite the switch to the point

where members engaged to actuate the switch to the "off" position.

FIGURE 2. Definition or rotation (shaft end view).

3.4.2.1 Clockwise taper. A clockwise taper is a resistance taper in which the resistance varies approximately as

shown on figure 3, increasing as the rotation angle increases in a clockwise direction as viewed from the operating

shaft, and measured between the terminals indicated as 1 and 2 on figure 2.

FIGURE 3. Clockwise taper.

3.4.2.2 Counterclockwise taper. A counterclockwise taper is a resistance taper in which the resistance varies

approximately as shown in figure 4, increasing as the rotation angle increases in a counterclockwise direction as

viewed form the operating shaft, and measured between terminals indicated as 3 and 2 on figure 2.