MIL-PRF-22097 Resistors, Variable, Nonwirewound, Adjustment Type, General Specification ForThis specification covers the general requirements for multi-turn lead screw actuated and single turn nonwirewound, variable resistors with a contact bearing uniformly over the entire surface of the entire resistive element, when positioned by the actuator. These resistors are capable of full load operation \(where maximum resistance is engaged\) at a maximum ambient temperature of 70 Degrees C and 85 Degrees C, and are capable for continuous operation when properly derated, at a maximum temperature of 125 Degrees C and 150 Degrees C \(see figure 1\). These resistors have a resistance of ┬▒10 percent \(see 3.1\).

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MIL-PRF-22097J

3.20 Life. When tested as specified in 4.7.15, resistors shall meet the following requirements:

Resistance between end

Change shall not exceed applicable value for total resistance specified in

terminals, with the contact arm in

table I between the initial measurements and each of the succeeding

the position for setting stability:

measurements.

Change shall not exceed 2 percent for characteristic A, and 1 percent for

Setting stability:

characteristic C and characteristic F.

Change shall not exceed the applicable value specified in table I.

Total resistance:

Dielectric withstanding voltage at

As specified in 3.10.

(atmospheric pressure):

Shall not exceed 150 percent of the specified operating torque (see 3.1).

Operating torque:

Visual inspection:

There shall be no evidence of mechanical damage.

3.21 Low temperature operation. When resistors are tested as specified in 4.7.16, resistors shall meet the

following requirements:

Setting stability:

Change shall not exceed 2 percent.

Operating torque:

Shall not exceed 150 percent of the specified operating torque (see 3.1).

Change shall not exceed the applicable value specified in table I.

Total resistance:

Visual inspection:

There shall be no evidence of mechanical damage.

3.22 High temperature exposure. When resistors are tested as specified in 4.7.17, resistors shall meet the

following requirements:

Setting stability:

Change shall not exceed 2 percent.

Total resistance:

Change shall not exceed the applicable value specified in table I.

Operating torque:

Shall not exceed 150 percent of the specified operating torque.

Dielectric withstanding voltage (at

As specified in 3.10.

atmospheric pressure):

Insulation resistance:

Shall not be less than 1,000 megohms.

Visual inspection:

There shall be no evidence of mechanical damage.

3.23 Rotational life. When resistors are tested as specified in 4.7.18, the change in total resistance shall not

exceed the applicable value specified in table I. There shall be no evidence of mechanical damage.

3.24 Terminal strength. When resistors are tested as specified in 4.7.19, there shall be no evidence of mechanical

damage, and resistors shall be electrically continuous.