1、 AMSC N/A FSC 5905 Comments, suggestions, or questions on this document should be addressed to: Defense Supply Center, Columbus, ATTN: DSCC-VAT, Post Office Box 3990, Columbus, Ohio 43218-3990 or by email Resistordla.mil. Since contact information can change, you may want to verify the currency of t
2、his address information using the ASSIST Online database at http:/assist.daps.dla.mil/ . INCH-POUND MIL-PRF-12934L 25 August 2009 SUPERSEDING MIL-PRF-12934K 14 April 2004 PERFORMANCE SPECIFICATION RESISTOR, VARIABLE, WIREWOUND, PRECISION GENERAL SPECIFICATION FOR This specification is approved for u
3、se by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 Scope This specification covers the general requirements for precision, wirewound, variable resistors whose electrical output (in terms of percent of applied voltage) are linear or nonlinear with respects to the angular po
4、sition of the shaft. This specification includes requirements for linear and nonlinear, single turn and multiturn, single-section (cup) and multisection variable resistors. These resistors are capable of full-load operation at maximum ambient temperatures of 70OC and 85OC and are suitable for contin
5、uous operation, when properly derated, to maximum temperatures of 125OC and 150OC (see 3.1, 6.2, and figure 10). This specification includes requirements for category I, category II, and category III precision resistors as described herein (see 3.2). 1.2 Classification: 1.2.1 Part or Identifying Num
6、ber (PIN). a. Category I resistors: The PIN completely describes the category I resistors of this specification. Single-section (cup) resistors RR0900 A 2 A 7 J 103 Style (1.2.1.1) Function and shaft length (1.2.1.2) Class and center tap (1.2.1.3) Resistance temperature characteristic(1.2.1.4) Rotat
7、ional life characteristic (1.2.1.5) Function conformity tolerance and resistance tolerance characteristic (1.2.1.6) Resistance (1.2.1.7) b. Category II resistors: The PIN of 1.2.1 is modified by changes in style designation (see 1.2.1.1), when used to describe a category II resistor. The PIN in this
8、 case does not fully describe the individual resistor. The resistor in this case is completely identified only by the addition of a drawing number in the marking (see 3.34 and 6.2.2). RR09XXA2A7J103 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL
9、-PRF-12934L 2 c. Multisectioned (ganged) resistors (category III): For multisectioned (ganged) resistors, the PIN includes the PIN for each section (cup), preceded by a digit denoting the number of sections (cups) in the gang, as indicated in the following example: 3RR09XXA2A7J103 3RR09XXA2A7J104 ga
10、nged (three cups) 3RR09XXA2A7J103 The PIN is listed in the order in which the sections (cups) are stacked (ganged), beginning with the section (cup) nearest the mounting surface. 1.2.1.1 Style. The style is identified by the two-letter symbol “RR” followed by a four-digit number. The letters “RR” id
11、entify precision, variable, wirewound resistors. The first two digits in the number identifies physical size, the last two digits identifies a category I or category II resistor. The digits for a category I resistor I should be “00”. The digits for a category II resistor will be “XX”. Example: RR090
12、0 - Category I resistor RR09XX - Category II resistor The category III item is not identified by a single number, but is described in the users drawing. 1.2.1.2 Function and shaft length. The type of function and shaft length are identified in accordance with table I (see 3.1). TABLE I. Function and
13、 shaft length. Length 1/ 2/ Symbol Servo mounted Bushing mounted (single turn) Bushing mounted (multi-turn) Function A 0.375 (9.53) 0.750 (19.05) - Linear B 0.500 (12.70) 0.875 (22.23) - Linear C 0.625 (15.88) 1.000 (25.40) 0.625 (15.88) Linear D 0.750 (19.05) 1.125 (28.58) 0.750 (19.05) Linear E 0.
14、875 (22.23) 1.250 (31.75) 0.875 (22.23) Linear F 1.000 (25.40) 1.375 (34.93) 1.000 (25.40) Linear X As specified As specified As specified As specified 1/ Length of shaft from mounting surface of resistor, nominal. 2/ Dimension in inches, metric equivalents are in parentheses. Tolerance is 0.031 ( 0
15、.787) 1.2.1.3 Class and center tap. The class and center tap is identified by a single digit in accordance with table II and as specified (see 3.1). 1.2.1.4 Resistance temperature characteristic. The resistance temperature characteristic of the completed resistor is identified by a single letter in
16、accordance with table III. 1.2.1.5 Rotational life characteristic. The rotational life characteristic is identified by a single digit in accordance with table IV (see 3.1). 1.2.1.6 Function conformity tolerance and resistance tolerance characteristic. The function conformity tolerance and resistance
17、 tolerance characteristic is identified by a single letter in accordance with table V (see 3.1) Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-12934L 3 TABLE II. Class and center tap. Symbol Class 1 Center tap 1/ Maximum ambient temperature
18、at rated wattage Maximum ambient operating temperatureTap located at center of resistive element (1 degree) 2 70OC 125OC Not applicable3 85OC 150OC Not applicable 4 70OC 125OC Applicable5 85OC 150OC Applicable X As specified As specified As specified 1/ Applicable only to linear function resistors.
19、TABLE III. Resistance temperature characteristic. Symbol Resistance-temperature characteristic in percent per OC 1/ A 0.003 B 0.005 C 0.010 D 0.016 E 0.026 F 0.040 G 0.070 H 0.100+ X As specified 1/ Referred to an ambient temperature at 25OC. TABLE IV. Rotational life characteristic. Symbol Rotation
20、al life (cycles) 1/ 2/ 3/ Single turn 3 turn 5 turn 10 turn 7 125,000 85,000 50,000 25,0008 250,000 175,000 100,000 50,000 9 500,000 350,000 200,000 100,000X As specified As specified As specified As specified 1/ A cycle consists of travel through 95 percent of actual electrical travel and return to
21、 starting point. 2/ For qualification only. 3/ Minimum number of cycles required. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-12934L 4 TABLE V. Function-conformity-tolerance and resistance tolerance characteristic. Symbol Function-conform
22、ity tolerance Resistance tolerance 1/ Symbol Function-conformity tolerance Resistance tolerance 1/ Percent Percent Percent Percent A 1.000 5 N 0.500 2 B 0.500 5 O 0.250 2 C 0.250 5 P 0.100 2 D 0.100 5 Q 0.050 2 E 0.050 5 R 0.025 2 F 0.025 5 S 1.000 1 G 1.000 3 T 0.500 1 H 0.500 3 U 0.250 1 I 0.250 3
23、 V 0.100 1 J 0.100 3 W 0.050 1 K 0.050 3 Y 0.025 1 L 0.025 3 X As specified As specified M 1.000 2 1/ The preferred resistance tolerances are 1 and 3 percent. 1.2.1.7 Resistance. The nominal total resistance value expressed in ohms is identified by a three digit number. The first two digits represen
24、t significant figures and the last digit specifies the number of zeros to follow. When fractional values of an ohm, or values of less that 10 ohms are required, the letter “R” is substituted for one of the significant digits to represent the decimal point. When the letter “R” is used, the succeeding
25、 digits of the group represent significant figures, as shown in the following example” 3R0 signifies 3.0 ohms 1.2.1.8 Example of PIN (category I resistor). The PIN RR0900A2A7J103 signifies: RR0900 - Precision, wirewound, variable resistor (single-turn) of the dimensions specified (see 3.1). A - Line
26、ar function and 0.375 inch (9.53 mm) shaft length. 2 - Resistance to moisture, and capable of rated-wattage operation at 70OC maximum, and when derated, at 125OC maximum (see figure 10). A - Resistance temperature characteristic of 0.003 percent per OC. 7 - Capable of 125,000 cycles of rotational li
27、fe. J - Function conformity tolerance of 0.10 percent and resistance tolerance of 3 percent. 103 - Nominal total resistance value of 10,000 ohms. 1.2.1.9 Example of PIN (category II resistor). The PIN RR09XXA2A7J103 signifies: RR09XX - Precision, wirewound, variable resistor (single-turn) with requi
28、rements as specified on acquisition document. A - Linear function and 0.375 inch (9.53 mm) shaft length. 2 - Resistance to moisture, and capable of rated-wattage operation at 70OC maximum, and when derated, at 125OC maximum (see figure 10). X - Resistance temperature characteristic of 0.003 percent
29、per OC. 7 - Capable of 125,000 cycles of rotational life. J - Function conformity tolerance of 0.10 percent and resistance tolerance of 3 percent. 103 - Nominal total resistance value of 10,000 ohms. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MI
30、L-PRF-12934L 5 2. APPLICABLE DOCUMENTS 2.1 General. The documents listed in this section are specified in sections 3 and 4 of this specification. This section does not include documents cited in other sections of this specification or recommended for additional information or as examples. While ever
31、y effort has been made to ensure the completeness of this list, document users are cautioned that they must meet all specified requirements documents cited in sections 3 and 4 of this specification, whether or not they are listed. 2.2 Government documents. 2.2.1 Specifications, standards, and handbo
32、oks. The following specifications, standards, and handbooks form a part of this document to the extent specified herein. Unless otherwise specified, the issues of these documents are those cited in the solicitation or contract (see 6.2). DEPARTMENT OF DEFENSE SPECIFICATION (See supplement 1 for list
33、 of specification sheets.) DEPARTMENT OF DEFENSE STANDARDS MIL-STD-202 - Test Methods Standard Electronics and Electrical Components Parts. MIL-STD-810 - Environmental Engineering Considerations and Laboratory Tests. MIL-STD-1285 - Marking of Electrical and Electronic Parts. DEPARTMENT OF DEFENSE HA
34、NDBOOKS FED-STD-H28 - Screw Thread Standards for Federal Services. (Copies of these documents are available online at http:/assist.daps.dla.mil/quicksearch/ or from the Standardization Document Order Desk, 700 Robbins Avenue, Building 4D, Philadelphia, PA 19111-5094). 2.3 Non-government publications
35、. The following documents form a part of this document to the extent specified herein. Unless otherwise specified, the issues of the documents which are those listed in the solicitation or contract. INTERNATIONAL ORGANIZATION for STANDARDS (ISO) ISO 10012 - Measurement Management Systems; Requiremen
36、ts for Measurement Processes and Measuring Equipment. (Copies of this document are available from http:/www.iso.org/ or from the American National Standards Institute, 11 West 42ndStreet, New York, NY 10036.) NATIONAL CONFERENCE OF STANDARDS LABORATORIES (NCSL) NCSL Z540.1 - Requirements for the Cal
37、ibration of Measuring and Test Equipment. (Copies of this document are available from http:/www.ncsli.org/ or from the National Conference of Standards Laboratories (NCSL) International, 1800 30thStreet, Suite 305, Boulder, CO 80301-1026.) 2.4 Order of precedence. Unless otherwise noted herein or in
38、 the contract, in the event of a conflict between the text of this document and the references cited herein (except for related specification sheets), the text of this document takes precedence unless otherwise noted. Nothing in this document, however, supersedes applicable laws and regulations unle
39、ss a specific exemption has been obtained. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-12934L 6 3. REQUIREMENTS 3.1 Specification sheets. The individual item requirements shall be as specified herein and in accordance with the applicable
40、specification sheet. In the event of any conflict between the requirements of this specification and the specification sheet, the latter shall govern (see 6.2). 3.2 Resistor categories. Resistors furnished under this specification shall be category I, category II, or category III, as defined herein.
41、 3.2.1 Category I resistor. A part that meets all requirements specified on a given specification without any exception, can be completely described by a PIN, (see 1.2.1) is covered by the family of products on the Qualified Products List (QPL), and is produced on an approved production line. Acquis
42、ition of these resistors shall be confined to sources whose family of products are listed on the QPL. 3.2.2 Category II resistor. A category II resistor is a part which is covered by the scope of a family of products qualification on an approved production line, but which differs from the category I
43、 item within the limits of similarity defined in 4.5.3. Acquisition of these resistors shall be confined to sources whose family of products are listed on the QPL. 3.2.3 Category III resistor. These resistors are of such a design, material, or construction that they can not be considered to fall wit
44、hin the scope of qualification (see 6.2.3). 3.3 Qualification. Resistors furnished under this specification shall be products that are manufactured by a manufacturer authorized by the qualifying activity for listing on the applicable qualified manufacturers list before contract award (see 4.4 and 6.
45、3). 3.4 Materials. Materials shall be used which will enable the resistors to meet the performance requirements of this specification. Acceptance or approval of any constituent material shall not be construed as a guaranty of the acceptance of the finished product. 3.4.1 Fungus. All external materia
46、ls shall be nonnutrient to fungus growth or shall be suitably treated to retard fungus growth. The manufacturers shall certify that all external materials are fungus resistant or shall perform the test specified in 4.7.28. There shall be no evidence of fungus growth on the external surface as a resu
47、lt of the test. 3.4.2 Pure tin. The use of pure tin, as an underplate or final finish, is prohibited both internally and externally. Tin content of resistor components and solder shall not exceed 97 percent, by mass. Tin shall be alloyed with a minimum of 3 percent lead, by mass (see 6.10). 3.5 Inte
48、rface and physical dimensions The resistors shall meet the interface and physical dimensions specified (see 3.1). 3.5.1 Operating shaft. All operating shafts shall be corrosion resistant. 3.5.1.1 Style. Unless otherwise specified, standard operating shafts shall be round (see 3.1 and 6.2). 3.5.1.2 L
49、ength. Unless otherwise specified, the lengths of standard operating shafts shall be in accordance with table I (see 3.1 and 6.2). 3.5.2 Contact arm assembly. Contact pressure on the resistance element shall be maintained by uniform positive pressure and shall permit smooth electrical and mechanical control of the resistor over the entire range of continuity travel (applicable to re
