DLA MIL-R-83579 CANC NOTICE 1: RESISTORS, FIXED, WIRE-WOUND (POWER TYPE), HIGH RELIABILITY, GENERAL SPECIFICATION FOR

This specification covers the general requirements for axial lead precision, power type, wire-wound, fixed resistors having a 25°C ambient operating temperature derated to zero load at 250°C for use in electrical, electronic communication, and other associated equipment and for space, missile and other high reliability applications. The prerequisite to qualifying to this specification shall be based on current qualification to "S" failure rate level for each detail specification of MIL-R-39007. Resistors of this specification shall be capable of meeting all requirements of MIL-R-39007 in addition to the requirements specified herein. These resistors have initial resistance tolerances of ±.5, ±.1, and ±1 percent as shown in table IV. Resistors which are noninductively wound with solderable leads are designated "N" while weldable leads are designated "Z". Resistors designated by the letter "S" and "W" are inductively wound with solderable and weldable leads, respectively (see 1.2.1.2).

The PIN shall be in the following form, and as specified (see 3.1 and 6.1):

The style is identified by the three-letter symbol "RWS" which represents high-reliability, axial-lead, power type, wire-wound, fixed resistors, and is to be used for reference only.

The resistor winding and the resistor lead type shall be as defined in table I.

Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document should be addressed to: SMC/SDFP, P.O. Box 92960, Worldway Postal Center, Los Angeles, CA 90009-2960, by using the Standardization Document Improvement Proposal (DD Form 1426) appearing at the end of the document or by letter. TABLE I. Resistor winding and resistor lead type.

Type     Resistor winding and lead type
--------------------------------------------------
    S       Solderable, inductively wound
    W       Weldable, inductively wound
    N       Solderable, noninductively wound 1/
    Z       Weldable, noninductively wound 1/

1/Wound using Ayrton-Perry method.

The nominal resistance is expressed in ohms and is identified by four digits; the first three digits represent significant figures and the last digit specifies the number of zeros to follow. When the value of resistance is less than 100 ohms, or when fractional values of an ohm are required, the letter "R" shall be substituted for one of the significant digits to represent the decimal point. When the letter "R" is used, succeeding digits of the group represent significant figures. The resistance value designations are shown in table II. Minimum and maximum resistance values shall be as specified (see 3.1). The standard resistance values for every decade shall follow the sequence demonstrated for 10 to 100 decade in table III. For resistance tolerances F and D, only those resistance values which follow the sequence of values listed in the 10 to 100 decade in table III shall be considered as conforming to this specification. TABLE II. Resistance values.

Designation                    Resistance (ohms)
-----------------------------------------------------------------------
  R100 to R988 inclusive             0.100  to        0.988 inclusive
  1R00 to 9R88 inclusive             1.00   to        9.88  inclusive
  10R0 to 98R8 inclusive            10.0    to       98.8   inclusive
  1000 to 9880 inclusive           100      to      988     inclusive
  1001 to 9881 inclusive         1,000      to    9,880     inclusive
  1002 to 4022 inclusive        10,000      to   40,200     inclusive

The resistance tolerance is identified by a single letter in accordance with table IV. TABLE IV. Resistance tolerance.

Symbol            Resistance tolerance
----------------------------------------------
                       Percent (±)

    B                  0.1
    D                  0.5
    F                  1.0

It is preferred that resistance values be selected as specified in table III. However, if it is impracticable to do so, then any value (within specification limits) may be specified and these values shall be considered as conforming to this specification (see table V and 3.1). TABLE V. Designation of resistance values (0.1 and 0.5 percent tolerances).

Designation                      Resistance value
----------------------------------------------------------------------

  R100 to R999 inclusive               .100 to       .999 inclusive
  1R00 to 9R99 inclusive              1.00  to      9.99  inclusive
  10R0 to 99R9 inclusive             10.0   to     99.9   inclusive
  1000 to 9990 inclusive            100     to    999     inclusive
  1001 to 9991 inclusive          1,000     to  9,990     inclusive
  1002 to maximum                10,000     to  maximum

Solderable

Weldable

Inductively wound

Noninductively wound