1、MILITARY SPECIFICATION TIMER, BOMBING, TYPE A-2 1. SCOPE timer equipment, designated Type A-2. 2. bids, shall form a part of this specification to the extent specified herein: 1.1 This specification establishes the requirements for one type of bombing APPLICABLE SPECIFICATIONS AND OTHER PUBLTCATIONS
2、 2.1 The following publications, of the issue in effect on the date of invitation for . . . . - . . . , . SPECIFICATIONS Military MIL-E-5272 MIL-E-5400 U. S. Air Force 7200 . STANDARDS Military MIL-STD-129 MIL-STD-130 DRAWINGS U. S. Air Force 48H21341 Environmental Testing, Aeronautical and Associat
3、ed . Electronic Equipment, Airborne, General Specification Equipment (General Specification For) For Electronic Equipment; Aircraft, Preseriation, Packaging, Packing and Marking for Shipment Of Marking of Shipments Idcntification Mariing of U. S. MlitCiry Timer, Bombing, Type A-2 I- . . . . . . . Pr
4、operty (Copies of specifications, standards, and drawings required by. contractors in connection with specific procurement functions should be obtiTincd fwrn the Procuring Agency.or as directed by the Contracting Officer.) -3 . , . ,. . ! “.“ .-_. - k:1:.lr:.1=: . . ._ ._ . - -I . -_-_ _-.-I. .- -.-
5、 .- . - . .- .- I _.-*_ .-.- . , . b. ,.-. . i- .- . ,. . I. I. . .I_. . .- -_ . _L . -.-.- . - _.-_ . -. . -_. , . ). . . .-.- . . . . i -. , . Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-momentary surges, exclusive of heater and external load
6、s. ampere and O. 5 ampere, respectively. 3.3.1.3 Relays: ! =-=:-.x-z.:x: . - . 3.3.1.3.2 Relays shall have a minimum pull in voltage of 2 volts less than . . relays Btt . 3.3 1.3.3 .Relays trBrr shall close on 18 volts or lesq. 3.4 Construction. - The timer shall be constructed in accordance with Dr
7、awing I_-. _-_-.I-_- -._ _._. _I.-.-I.-.-.% I .-. -_-I- -, ._-.I-. . .- . No. 48H21341 and details thereof. . -. . .- -. .-.-II -_-_. I._*_ . . . . 3.4.1 .Heater. - A suitable auxiliary heater ahall be pcluded to permit correct * . - -.- -.-.-. . . . . .- .-. . . L _. -._. . b . - . , -. -.-. I- . .
8、 -. . operation at lmv temperatures. It shall be controlled by Uiermostat switch and connected ta pin G of Uie receptaclij, The thermostat nlnU suitable snap actiou I :. . : . . . I . ,. . - . .-. close at 40F and open at 50F, i. . . .I -. 8 , . 3.5 Performance: / -. .,. I .- c . . - . Provided by
9、IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- . MIL-T-7045 bb W 77777Ob 0127015 b W -3-. MIL-T-9045( USAF) 3.5.1 Operation. - The timer shall operate as specified below when terminal H is connected to a positive dc power source of proper voltage and terminal
10、I connected to the negative of the same source: (See wiring diagram shown on Drawing No. 48B21334.) 3.5.1.1 Terminal F shall be energized from terminal H. 3.5.1.2 With a positive external impulse applied to terminal C, the 1 to 4 second timing element shall be initiated. 3.5.1.3 .During the time tha
11、t terminal C is energized, power will be available to terminal A froni terminal H, 3.5.1.4 At the termination of the preset interval of the 1 to 4 second timing 3.5.1.5 One or more intermittent impulses from an external source, when applied element, power stall be applied to terminal D from terminal
12、 H. to ternira1 E shall condition the 2.5 seconds timing clement to deliver power to terminal B from terminal H after 2.5 seconds have elapsed from the termination of the last impulse. at operating vollirgcs of 24 to 30 volts dc. 3.5.2 Accuracy. - The timer shall operate within the following accurac
13、y limitations - 3.5.2.1 The 1 to 4 second timing element shall be accurate to 2 1.25 percent of any preset interval. Duration of any preset interval shall be the average of at least 10 readings taken at an ambient temperature of 70 to 75OF and an operating voltage of 27.5 to 28 volts as measured at
14、the timer terminals. . NOTE: All timers are delivered with the 1 to 4 second timing element preset to 2. O seconds, unless otherwise specified by the kocuring Agency. 3.5.2.2 The 2.5 second timing element shall be accurate to 2 10 percent. 3.5.2.3 An external impulse of 0.025 second applied to ter-:
15、 I . 4.2.6 Life. - I 4.3 Inspection Test Procedures: . .- .-. . . . . ,_ . . . , ._- - . . )._.I_ II_ . .- 4.3.1 Sampling Tests. - Timerer rqn-esentave of a CBrBluTC;, .- . .- - . . .-. . nnd vibration lests specified irz 4,2 and the ;ndivh.lual teat of 4.3,2, . - . QB .*s I - . . - Provided by IHSN
16、ot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-T-9045( WAF) . 4.3.3 individual Tests. - Each timer will be operated under normal conditions 4.4 Additional Test Procedures. - Further procedures and methods for conducting . . . - . . and shall function as specifi
17、ed in 3.5. Preproduction and Inspection Tests shall be prepared by the contractor and sent to the . Procuring Agency forapproval. The Procuring Agency may request additional tests to determine compliance with the requirements of this specification when this is deemed necessary. 5, PREPARATION FOR DE
18、LIVERY 5.1 General. - The timer shall be prepared for delivery in accordance with Specification 7200, Method II. 5.2 Marking. - Markkg of interior packages and exterior shipping containere shall be in accordance with Standard MiLSTD-129, 6, NOTES I 6.1 Use, - The Type A-2 Bombing Timer as covered by
19、 this specification is intended for use on bombardment aircraft to obtain automatic operation of the bomb bay doors in conjunction with the release of bombs. , 2 .Ordering Datai- Requisitions, Purchase Orders and Contracts should state tho name, and type and model designation of the equipment, the t
20、itle, number and date o and list the components by name and type designations as appearing on the current Parts Control List; whether overseas or domestic packing i8 desired. 6.2. P Tools and Test Equipment. .- If tools (AN-D-17) and test equipment (MIL-T-945) are required in quantity, they should b
21、e cailed or by a separate item of the contract. 6.2.2 Preproduction Tests. - It is expected that the contract or purchase order will specify that one timer will be required as the preproduction sample and that it will be subjected to the preproduction tests to determine compliance with the require-
22、ments of this specification. The invitation for bids and the contract s:o.ild specify the point of inspection for these tests. NOTICE: When Government drawings, specifications, or other data- are used for any purpose other than in comection with a definitely related Government procurement operation,
23、 Wie United Sktea Government thereby incurs no responsibity nor any obligation whatsoever; md the fact that the Government may have formulated, furdolied, or in any way supplied the said drawings, specifications, or other : . .*. . :. - i i Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
