1、. _- MIL-P-25755 58 m b 015q587 O . . . . . . . . . . 1 . . . . . 1 . . -1 . . . . _ - - - i .-_- . .=- . . - . . . . . . . 3 . 1 I . . . . . . j 1 . -.-. . . , . i . I . . . . -1 J . .j . . . . . I . J , 4 . + .-.-I ., . . 1 -. . .-._. . - . . 1 . . 4 . , _- I_.I_ .- .i . . . . - . 1 . . . . . . .-
2、. -. . 1 . -.- i. . . . . 1 . . . - A- - . - .- MIL-P-28785 (EC) 3.5.7 Temperature coefficient of output voltage. Temperature coefficient of output voltage shall be less than .O2 percent per degree Centigrade when tested as specified in 4.5.2.7. 3.6.8 Voltage regulation. Voltage regulation shall be
3、.O1 percent maximum when tested as specified in 4.5.2.2. 3.6.9 Voltage ripple. Voltage ripple shall be 0.5 mV maximum when tested as specified in 4.5.2.3. 3.6.10 Output impedance. The output impedance shall be .O04 ohms maximum when tested as specified in 4.5.2.4. 3.6.11 Overload. The power supply s
4、hall be capable of operating into a short circuit without damage when tested as specified in 4.5.2.10. to the test the power supply shall not be damaged and shall meet the require- ments of 3.6.2,through 3.6.5. A blown fuse is not considered damage or failure. Subsequent 3.6.12 Terminal grounding. E
5、ither the positive or negative dc terminal may be grounded or operated at 200 Vdc from ground. - . . -.- -. . . _.- . ,_._. . .- I._._. . - .*I- . . - .-. . -.- . _._ I. . . . . . I 3.6.13 Run-in. The power supply shall be subjected to a 48 hour run-in test in accordance with 4.5.2.8. Subsequent to
6、the test the power supply shall not be damaged and shall meet the requirements of 3.6.2 through 3.6.5. -_ _ _ . 3.6.14 Insulation resistance. Insulation resistance shall be 500 megohms , , - minimum when tested as specified in 4.5.2.9. 3.6.15 Output ammeter. The output ammeter shall have a range of
7、O to 5 amperes. 3.6.16 Output voltage meter. The output voltage meter shall have a range of O to 50 volts dc. 3.7 Construction 3.7.1 Case. The case shall be a ventilated steel case, dripproof 15 protected in accordance with MIL-STD-108 and shall not exceed 9 x 10 x 15 inches and finished in black vi
8、nyl enamel. 3.7.1.1 Front panel. The front panel shall be anodized aluminum in accordance with MIL-A-8625 with etched black letters. An ammeter of O to 5 amps range and.a voltmeter of O to 50 volts range shall be mounted on the front panel. Figure 1 may be used as a guide. 3.7.1.2 Panel controls, me
9、ters and protective devices. The front panel shall include the following: (a) (b) Power-on indication Iight Power on-off switch or circuit breaker (c) Output voltage controls . . . , . ., . , . .- 7 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL
10、-P-28785 58 m 7779706 0154870 O m I t 1. . MIL-P-28785 (EC) (1) coarse (2) fine Output current controls (1) coarse (2) fine Out put ammet er Output voltmeter Over-voltage indicator light Output terminals shall provide a positive output, negative output and chassis ground. 3.7.2 Rear of case 3.7.2.1
11、The rear of the case shall include the following: (a) Input line fuse (b) Input terminals . (c) Output terminals shall provide a positive output, negative output and chassis ground. 3.7.2.2 The fuse holder. The 3.8 Weight. pounds. rear of the case shall contain the input terminals and line input lin
12、e fuse shall be in an indicating fuse holder. The weight of the power supply shall be not greater than 50 3.9 Marking. The power supply shall be marked in accordance with MIL-STD- 1285 and MIL-STD-130. Markings shall remain legible after all tests. 3.10 Workmanship. Workmanship shall be in accordanc
13、e with requirement 9 of MIL-STD-454. 4. QUALITY ASSURANCE PROVISIONS 4.1 Responsibility for inspection. contract or purchase order, the supplier all inspection requirements as specified Unless otherwise specified in the is responsible for the performance of herein. Except as otherwise specified, the
14、 supplier may use his own facilities or any other facilities suitable for the performance of the inspection requirements specified herein, unless dis- approved by the Government. The Government reserves the right to perform any of the inspections set forth in the specification where such inspections
15、 are deemed necessary to assure supplies and services conform to prescribed requirements. 4.2 Classification of inspection. The inspections specified herein are classified as follows: (a) (b) First article inspection (see 4.3) Quality conformance inspection (see 4.4) 1. Inspection of preparation for
16、 delivery (see 4.4.2) 4 . . . -. -. . . . . _- . . . . . . i . . _ . ,. ,. . . ,. _-. . . . . . . . . _._. . . 1:;: . . , . *.- . .- . . . .- ). I-. . _.- b :I: I-. . - . . . , . Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I -. -._ . . . . i ._ t
17、 . . . 1 . .l . . .-. - -_. . -. -.-_ - -.- a - .-. -4 - . * .- ._. . .- .-, . - _ - y -_ - * I %. .-. 2 n._ . . , .-_ . . . . -.-.I.- . -4 . - . ._ -.-.-.- 1 . -.- . .-_. - - . -. - - - . . . . . * . . i . i $ . 1 . . . -_ -.3 4 ! , . , . . I .- - -._.- . 4 4 -I_._-.- .q I -.- - 1 . . . . . . - .-_
18、 .- . .1 .-_ . .- , . . -_. . .-. . - .-.- . - . . -I . . . . . . - . -. . . 1 . . . . .- * 1 .- . . . . . . 1 . . . 1 * . - - - . . . . ._ -_I_I- - . . .-. -. -. -.-. , _. _.-._ .- . .-. - - . . ,_._._ -.-.-. .-I . ,. . . . -_. .- - . ,. . .-. . .“ . -. . . . -.- -. I: .-. i- L . F: ,. I . .-. . .
19、. _.- -. . - . . _. . . . _I - NIL-P-28785 (EC) Figure 1. Front panel NOTE: For similarity of mechanical contxuction 5 /= Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-P-Z785 58 m Ob OL5Li92 4 = MIL-P-28785 (EC) . . . . . . . I -. . . 4.3 First
20、 article inspection. Unless otherwise specified (see 6.2), 2 units shall be required for first .article inspection. shall consist of all examination and testing necessary to determine compliance with the requirements of this specification. First article inspection shall include the tests specified i
21、n table I. The first article inspection shall be witnessed and approved by the command or agency concerned. First article inspection . . . . . . _.-_- ._ . . -. I . - . . . . . Table I. First article inspection Examinat ion Visual :;:;$ . .- - - . . i _. , , . - - MIL-P-28785(EC) Table II. Quality c
22、onformance inspection Examination Requirement Method Visual 2 through 3.6.5. After 4 hours at -20 C the power supply shall be removed The power supply shall be placed in a chamber at +85O C 4.5.2 Electrical 4.5.2.1 Operating test. Input power of 105 to 125 volts, 57 to 63 Hz to the power supply. cur
23、rent with panel controls so that panel meters read 10, 20, 30, 40 and 50 volts at 1, 2, 3, 4 and 5 amps, respectively. Attach 1/2 percent accuracy voltmeter and ammeter to output terminals. The reading on the panel meters shall be within k 2 percent of the applicable voltage and current on the test
24、meters. When the power supply is adjusted for a dc load of 50 volts, 5 amps determine the primary power drain (see 3.6.4). With appropriate load applied, adjust output voltage and 4.5.2.2 Voltage regulation. Using a voltmeter having an accuracy of 112 percent, measure the output voltage at no load c
25、onditions and at full load conditions of 50 Vdc 5 amps and determine the percent change between no load and full load conditions. 4.5.2.3 Voltage ripple. At full load conditiohs of 50 Vdc 5 amps, place an oscilloscope across the output terminals and determine the voltage ripple in millivolts. 4.5.2.
26、4 Output impedance. At nonoperating condition, place an impedance meter across the output terminals and determine the output impedance. 4.5.2.5 Line regulation. At full load conditions of 50 Vdc, 5 amps, place a voltmeter having an accuracy of 1/2 percent across the output terminals. Vary the input
27、voltage from 105 to 125 Vac and determine variation of output vol tage. 4.5.2.6 Stability. Operate the power supply at full rated load of 50 Vdc, 5 amps for 24 hours. After warm-up, but prior to initiation of the 24-hour test, measure output voltage across output terminals using 112 percent accuracy
28、 meter. After 24 hours measure output voltage across output terminals using 1/2 percent accuracy meter. voltage measured after warm-up and prior to 24-hour test and after 24-hour test. Compute percent change in output voltage between 4.5.2.7 Temperature coefficient of output voltage. Operate the pow
29、er supply into a full rated load of 50 Vdc, 5 amps at 25O C and measure output voltage. and measure output voltage. shall be after the power supply has stabilized. Calculate percent changes of voltage per degree Centigrade. Increase temperature of chamber to 50 C without adjustment of controls Deter
30、mination of output voltage at each temperature 4.5.2.8. Run-in test. The power sup ly shall be operated at full rated load of 50 Vdc, 5 amps for 48 hours at 25 C. Subsequent to the test the . . I . i: . . . -. -._ . ,_._._ _._.- . . -_._ . . . . . . I -1 . . . i l 1 )._ J . , . ,_ ) .-. . +-.- . , .
31、 ,I :z.:zxz:xxx:= . . - . . - - . _ I _. . . . -. . . . -_, I.- . - . - ._ -. - I . %-. I , . ii ._. . _. . % . . . L . r-l-=- .-. ._ . . I ._ .-.-. . -. . . . . ._ . -.- _.-_. . . .- . ._._I -.I_- -_ . . . .- . . -. -,-*. . . . _ - , . -.-. ,-_.- . .- . . . ,. . r_._ . . , I . . . . -_ . -. . L . .
32、 . .-. _ _I.I . -_-. . _.-. - . _._. .- . I- .-_. . - . . I_ *-.-_.-I .-.-.- _-_./-. _-_._ _. _I_.-._-_._ -._- .- . I_. - ,_- _ _ . . .- _. . .- . . - 1- - - . -.- I -.- -. _ - - -. - I - - - I - . - - -. . _._. . “.-.- .A. . . .- . . . . . i Provided by IHSNot for ResaleNo reproduction or networkin
33、g permitted without license from IHS-,-,-. . . . . . . . . . 4 . . . . - . . . .- . . . _-._- . -_-. - - . - -. I .-. . z - . - . . . . - . . . “ . x . -. .-. . .- . i . _ . . I. . .- _ - . . . . . . 1 . . . - i . .-._ . . . . . . . -. . - . 1 .- - I._. _. . . - . . . . . .- . . - 1 _ - .-I . 4 . .
34、._. . . . .- . i . . . . 1 . . . . . . - . . . . . . _-._ - . . . . . .- - . . . . . . .-. . _. . . -. _ . i . . . . 4 . , :I . . ._.- power supply shall be inspected for damage and measurements shall be made to determine conformance with 3.6.2 through 3.6.5. 4.5.2.9 Insulation resistance. Insulatio
35、n resistance shall be conducted . in accordance with ML-STD-202, Method 302, test condition B. be made between terminals, and terminals to ground. Measurements shall 4.5.2.10 Overload. Apply a short circuit across output terminals when the power supply is being operated at full rated output of 50 vo
36、lts and 5 amperes, Subsequent to the test the power supply shall be inspected for damage and meas- urements shall be made to determine conformance with 3.6.2 through 3.6.5. 5. PREPARATION FOR DELIVERY (The preparation for delivery requirements specified herein apply only for direct Government procur
37、ements. referenced documents listed in Section 2 do not apply unless specifically stated in the contract or order. procured by contractors shall be specified in the individual order.) Preparation for delivery requirements of Preparation for delivery requirements for products 5.1 Preservation and pac
38、kaging, packing, and marking. Unless otherwise specified, preparation for delivery shall be in accordance with ML-E-17555 (see 6.2). 6. NOTES .- 6.1 Intended use. The power supply is used to convert the primary . . , power to dc voltages necessary to operate Navy electronic equipments. -._ . 6.2 Ord
39、ering data. Procurement documents should specify the following: (a) Title, number, and date of this specification (b) (c) Number of first article samples to be submitted if other than Xarking, levels of preservation and packaging and packing specified in 4.3. required (see 5.1) 6.3 First article. in
40、vitations for bids should provide that the Government reserves the right to waive the requirements for first article samples as to those bidders offering a product which has been previously procured or tested by the Government, and that bidders offering such products, who wish to rely on such produc
41、tion or test, must furnish evidence with the bid that prior Government approval is presently appropriate for the pending procurement. . . . . 1 . Preparing activity: . Navy - EC (Pro j ect 5820-NS59) . .- . . . . I._ . . . . . . L/- . * U. S. GOVERNMENT PRINTING OFFICI5 1972-714-536/773 9 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
