NPFC - MIL-T-21038
TRANSFORMERS, PULSE, LOW POWER GENERAL SPECIFICATION FOR
| Organization: | NPFC |
| Publication Date: | 11 May 1979 |
| Status: | inactive |
| Page Count: | 52 |
scope:
This specification covers the general requirements for low-power pulse transformers for use in electronic and communications equipment. This specification covers transformers where the peak pulse power is 300 watts or less and the average pulse power is 5 watts or less. Procurement of transformers of a specific design will require additional data in the form of complementary service documents giving detailed electrical and mechanical requirements and applicable additions and exceptions to the general requirements and tests specified herein. (See 6.1.)
The type designation shall be in the following form, and as specified (see 3.1, 6.1, and 6.3):
Low-power pulse transformers are identified by the two-letter symbol "TP".
The grade is identified by a single digit denoting metal encased or encapsulated or open type of construction, and the ability of the transformers to withstand the environmental tests of table I.
These units are sealed, metal encased with separately fabricated headers and terminals. This grade does not include units which are encapsulated in a metal shell with an opening in either end or side of the shell, or with insulated lead wires exiting through the metal shell.
These units are encapsulated, including molded or embedded constructions, and units with a metal shell, open at one or both ends and filled with encapsulant material. Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document should be addressed to: Commander, Naval Electronic Systems Command, ATTN: ELEX 5043, Department of the Navy, Washington, D.C. 20360 by using the self-addressed Standardization Document Improvement Proposal (DD Form 1426) appearing at the end of this document or by letter. TABLE I. Grade.
Test Grade 4 Grade 5 Grade 6 Grade 7
metal-encased encapsulated metal-encased encapsulated
--------------------
The class is identified by a single letter in accordance with table II, denoting the maximum operating temperature (temperature rise (see 4.7.14) plus maximum ambient temperature) for realization of the life expectancy indicated in table III (see 6.5). TABLE II. Class.
Symbol Maximum operating
temperature, °C
--------------------
The life expectancy is identified by a single letter in accordance with table III (see 6.5). TABLE III. Life expectancy.
Symbol Life (hours)
--------------------
The turns ratio for the first four windings is identified by a four-digit number. For two-winding transformers, the last two digits shall be zero; for three-winding transformers, the last digit shall be zero. Examples of turns-ratio designations are as follows:
Turns ratio Symbol 1:1 (two windings) 1100 1:2 (two windings) 1200 1:1:1 (three windings) 1110 1:1:1:1 (four windings) 1111 Nonstandard NNNN
For transformers with nonstandard ratios (for instance, 7.1:6, 7:5.3) or more than four windings, the identifying symbol shall be "NNNN".
The style is identified by a single letter in accordance with figure 1.
The envelope dimensions are identified by one or two letters (see table IV). Specific physical configurations shall be as specified (see 3.1).
Document History
