1、AMSC N/A FSC 6645 INCH-POUND MIL-DTL-7793/2B 19 October 2012 SUPERSEDING MIL-M-7793/2A 15 September 1988 DETAIL SPECIFICATION SHEET METER, TIME TOTALIZING, MINIATURE, DIGITAL, 28 VDC, ROUND This specification is approved for use by all Departments and Agencies of the Department of Defense. Reactivat
2、ed after 19 October 2012 and may be used for new and existing designs and acquisitions. The requirements for acquiring the product described herein shall consist of this specification sheet and MIL-DTL-7793. FIGURE 1. Meter configuration. 1.000 Provided by IHSNot for ResaleNo reproduction or network
3、ing permitted without license from IHS-,-,-MIL-DTL-7793/2B 2 REQUIREMENTS: 1. Dimensions. Dimensions are in inches. Unless otherwise specified, tolerances are .02 for two-place decimals and .015 for three-place decimals. 2. Mounting flange. Meters with fixed flanges shall be tin plated on the front
4、surface of the mounting flange in accordance with ASTM-B545 to provide an electrical ground for the case. In accordance with Table I, meters may be furnished with no flange or with adjustable split mount flanges in accordance with MS3345-1. 3. Life accuracy. Meter accuracy shall be 0.1 percent from
5、-85 to 257 F (-65 to 125 C) and 10 to 34 VDC. 4. Power consumption. The average power consumption at 28 volts direct current (VDC) shall not be greater than 85 milliwatts. 5. Ripple voltage. The meter shall continue to operate as specified in MIL-DTL-7793 when subjected to a cyclic peak of ripple vo
6、ltage (see Note 3) of less than 2.0 VDC and the frequency-voltage coordinates of figure 2. 5.1 Ripple voltage measurement. The ripple voltage shall be measured with a peak reading voltmeter in series with a 4.0-microfarad capacitor. The higher of the two values measured when the voltmeter is success
7、ively connected to each of two polarities shall be considered the ripple voltage. 5.2 Frequency characteristics. The frequency components of the ripple voltage shall be within the limits on figure 2 when measured as conducted interference. 6. Operating temperature range. The operating temperature ra
8、nge shall be from -85 to 257 F (-65 to 125 C). 7. Voltage range. The operating voltage shall be from 10 to 34 VDC. 8. Time range. Total readout of the meters shall be 9,999 hours. 9. Transient protection. No temporary or permanent degradation shall be produced in the meter for the input voltage and
9、time values shown on figure 3 and figure 4 (80V and 600V transient, respectively). 9.1 Transient voltage. Transient surge voltages shall be within the limits on figure 3 when converted to their equivalent step functions. Transient spike voltages shall be within the limits shown on figure 4. They sha
10、ll be not greater than 600V nor depart from the normal wave form for more than 50 microseconds. 10. Weight. Weight shall be not greater than 0.6 ounce with flange. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-7793/2B 3 11. Dielectric stren
11、gth test voltages. The dielectric test voltages shall be 350 V root mean square (rms) at altitude specified in MIL-DTL-7793 and 600 V rms at room ambient pressure and temperature (approximately 25 C). 12. Qualification tests. Qualification tests shall be conducted in accordance with MIL-DTL-7793, ex
12、cept that the accuracy, voltage, temperature, dielectric strength test voltages and accuracy shall be as specified herein. TABLE I. Dimension A of flange in figure 1. Military Part Number Flange Data Dim A .015 Military Part Number Flange Data Dim A .015 M7793/2-001 Adjustable per MS3345-1 M7793/2-0
13、15 .375 M7793/2-002 No Flange M7793/2-016 .406 M7793/2-003 .000 (Flush) M7793/2-017 .438 M7793/2-004 .031 M7793/2-018 .469 M7793/2-005 .062 M7793/2-019 .500 M7793/2-006 .094 M7793/2-020 .531 M7793/2-007 .125 M7793/2-021 .562 M7793/2-008 .156 M7793/2-022 .594 M7793/2-009 .188 M7793/2-023 .625 M7793/2
14、-010 .218 M7793/2-024 .656 M7793/2-011 .250 M7793/2-025 .688 M7793/2-012 .281 M7793/2-026 .719 M7793/2-013 .312 M7793/2-027 .750 M7793/2-014 .344 M7793/2-028 .781 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-7793/2B 4 FIGURE 2. Frequency c
15、haracteristics of ripple in 28 VDC electric systems. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-7793/2B 5 FIGURE 3. Transient surge step function loci limits. Time (Seconds)DC Volts Provided by IHSNot for ResaleNo reproduction or network
16、ing permitted without license from IHS-,-,-MIL-DTL-7793/2B 6 10-6 FIGURE 4. Envelope of spike voltages for direct current. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-7793/2B 7 13. Changes from previous issue. Marginal notations are not u
17、sed in this revision to identify changes with respect to the previous issue due to the extent of the changes. Referenced documents. In addition to MIL-DTL-7793, this specification sheet references MS3345 and ASTM-B545. Custodians: Preparing activity: Army - AR Navy - AS Navy -AS (Project 6645-2012-0
18、04) Air Force - 99 Review activity: DLA - GS1 NOTE: The activities listed above were interested in this document as of the date of this document. Since organizations and responsibilities can change, you should verify the currency of the information above using the ASSIST Online database at https:/assist.dla.mil. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
