1、BRITISH STANDARD BS G133:1951 Incorporating Amendment No.1 Specification for Electro-magnetic indicators for extra low voltage aircraft systems UDC629.13.056BSG133:1951 This BritishStandard, having been approved by the Aircraft Industry Standards Committee and endorsed by the Chairman ofthe Engineer
2、ing Divisional Council, was published under theauthority of the General Council on 6 September1951 BSI02-2000 ISBN 0 580 34525 4 Foreword Warning lights as indicators of the condition of electrical circuits tend to confuse the pilot, particularly when they remain illuminated: this BritishStandard pr
3、ovides an alternative in the form of a magnetic indicator which can give a continued indication of the maintenance of a certain condition in a circuit without irritation to the pilot. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standard
4、s are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, pages1 to3 and a back cover. This standard has been updated (see
5、 copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date of issue Comments 1273 September 1951 Indicated by a sideline in the marginBSG133:1951 BSI 02-2000 i Contents Page For
6、eword Inside front cover Section 1. General requirements 1 Scope 1 2 ConstructionGeneral 1 Section 2. Design requirements 3 Operation 1 4 Presentation 1 5 Operating voltage 1 6 Temperature rise 1 7 Vibration, acceleration and climatic proofing 1 8 Magnetic interference 2 9 Marking 2 Section 3. Tests
7、 10 General 2 A. Type test 11 Vibration test 2 12 Acceleration test 2 13 Climatic proofing 2 14 Functioning tests 2 15 Compass safe distance 2 16 Endurance test 2 17 Temperature rise test 2 18 High voltage and insulation resistance tests 3 B. Type test 19 Functioning test 3 20 High voltage and insul
8、ation resistance tests 3 Figure 1 Holes in panel 1ii blankBSG133:1951 BSI 02-2000 1 Section 1. General requirements 1 Scope This BritishStandard applies to a single-pole or multi-pole indicator comprising a flag or shutter, operated electro-magnetically at a nominal voltage of24volts D.C., giving a
9、visible signal appropriate to the state of the electrical circuit or circuits to which it is connected. 2 ConstructionGeneral The indicator shall satisfy the general airworthiness requirements specified in Part1 1)of BS G100 2)“General requirements for electrical equipment and indicating instruments
10、 for aircraft.” It shall be so designed that it may be mounted in any attitude without affecting its operational efficiency. The preferred fixing arrangement is that which would render the indicator interchangeable with the existing British aircraft warning light, the fixing holes of which are as sh
11、own in Figure 1. Section 2. Design requirements 3 Operation The indicating flag or shutter shall be operable to one or more positions, apart from the null position. The means of operation shall be such that any one signal is rapidly presented and it shall be impossible for the flag or shutter to rem
12、ain in any position beyond or between these signals. 4 Presentation Signals shall be clearly distinguishable by suitable colouring, marking, fluorescing, or luminizing of the flag or shutter. Fluorescent brightness shall conform to the requirements of BS G100. A plain matt black surface shall be pre
13、sented when the supply is discontinued and, if possible, when there is any failure of the indicator. The window of the indicator shall have a clear area of not less than0.07sq. in. and its smallest dimension shall be not less than 3 / 16 in. The dimensions and shape of the shutter or shutter segment
14、 and/or indicator window shall be such that it is possible to distinguish the indicator signals clearly at any point within a cone subtending an angle of not less than120 at the window, with the axis of the cone normal to the plane of the window. No portion of an unwanted signal shall be visible whe
15、n the indicator is viewed from within that cone. 5 Operating voltage The indicating mechanism shall be designed to function normally within an applied D.C. voltage range of20 to28.5volts. The mechanism shall give a positive and rapid change of signal at all voltages in this range, and shall return t
16、o the null position if the voltage drops to a value of less than3volts. The requirements of this clause shall be fulfilled irrespective of the polarity of the connections to the supply. 6 Temperature rise When the indicator is continuously energized at28.5volts D.C. the temperature rise of the windi
17、ngs shall be within the limits specified in BSG100. 7 Vibration, acceleration and climatic proofing The design and construction of the indicator shall be such as to satisfy the requirements of BS G100 in respect of: a) vibration, including resonanceGrade III. b) accelerationGrade II. c) climatic pro
18、ofingGrade II. 1) This indicator is not an indicating instrument within the meaning of Part2 of BS G100. 2) In course of preparation. Figure 1 Holes in panelBSG133:1951 2 BSI 02-2000 8 Magnetic interference The indicator shall be designed to be suitable for mounting near a compass and it shall be co
19、nstructed to satisfy the requirements of BS G100 in respect of magnetic interference. 9 Marking Each indicator shall be clearly and indelibly marked with the following information: a) the number of this BritishStandard, i.e.BSG133. b) manufacturers name or identification. c) type number. d) operatin
20、g voltage. Section 3. Tests 10 General Tests shall be made to prove compliance with all requirements of this BritishStandard. It is not intended or recommended that complete tests shall be made on every indicator supplied. Two kinds of tests, therefore, are specified as follows: A. Type tests (Claus
21、es1118) which shall be made on each particular class of indicator. B. Routine (individual) tests (Clauses1920) which shall be made on every indicator manufactured to this BritishStandard. The tests prescribed in Clauses1114 inclusive and Clause18 shall be performed in that order on the same indicato
22、r, but tests in Clauses1517 inclusive may be taken on another indicator or indicators. Unless otherwise specified below, the voltage applied to the operating coils during tests shall be28.5volts D.C. A. Type tests 11 Vibration test The indicator shall undergo the Grade III vibration test, including
23、resonance, specified in BS G100. 12 Acceleration test The indicator shall undergo the Grade II acceleration test specified in BS G100. 13 Climatic proofing The indicator shall undergo the Grade II climatic tests specified in BS G100. 14 Functioning tests During the vibration, acceleration and climat
24、ic tests the indicator shall operate satisfactorily over25 complete cycles of operation at not more than10cycles per minute at an applied voltage of20volts D.C. and shall comply with the requirements of Clause5 in relation to drop-out voltage for a further25 cycles of operation. Each cycle shall com
25、prise operation of the movement over its entire range of signals, including return to the null position. 15 Compass safe distance The indicator shall undergo the test specified in BSG100 to determine compass safe distance and, for equipment to be mounted near a compass, the results of the test shall
26、 be declared by the manufacturer. 16 Endurance test The indicator shall undergo, at normal ambient temperature and pressure, an endurance test consisting of100000 complete cycles of operation, together with periods in which the coils are continuously energized. The rate of operation shall not exceed
27、100 cycles per minute. The indicator shall function satisfactorily throughout this test. The endurance test shall be conducted in the following manner: a) 50000 cycles with the front face of the indicator vertical, in25000 of which the flag or shutter shall move vertically and in the other25000 hori
28、zontally, followed by one hour continuously energized in each signal position with the front face of the indicator vertical. b) Repeat tests under a) but with25000 cycles with the front face of the indicator upwards and25000 cycles with the front face of the indicator downwards. 17 Temperature rise
29、test The temperature rise of the winding shall be measured at the conclusion of the test specified in Clause16 and shall not exceed the limits specified in BS G100. A test shall be made to prove that the indicator complies with the requirements of Clause5 in relation to drop-out voltage.BSG133:1951
30、BSI 02-2000 3 18 High voltage and insulation resistance tests a) An A.C. test voltage of500volts at50cycles per second shall be applied for one minute between all terminals connected together and the frame of the indicator. b) When the indicator has an all-insulated case it shall be mounted on a met
31、al panel and the test voltage applied between the terminals and the panel and between all terminals not normally connected together, with all contacts open. c) Immediately following the tests in a) and b) above, the indicator shall be tested for insulation resistance in the manner defined in BS G100
32、 using an applied voltage of500volts D.C. The insulation resistance at room temperature shall be not less than5 megohms when measured between any winding and the frame. B. Routine tests 19 Functioning test Each indicator shall be tested for correct mechanical functioning over80complete cycles of ope
33、ration (asdefined in Clause14) at the rate of not more than10cycles per minute. 40cycles shall be performed with the indicator face vertical, in20 of which the flag or shutter shall move vertically and in the other20 horizontally,20 with the face upwards, and20 with the face downwards. Of10cycles of
34、 each of these groups of20,5cycles shall be performed at an applied voltage of20v.D.C., and5 to ensure that the drop-out voltage is above the minimum specified in Clause5. 20 High voltage and insulation resistance tests Each indicator shall undergo the high voltage and insulation resistance tests de
35、scribed in Clause18.BS G133:1951 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for preparing BritishStandards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter
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