ARINC 538B-1-1983 HAND-HELD microphone.pdfARINC429

文件名称: ARINC 538B-1-1983 HAND-HELD microphone.pdf

所属分类: 其它

开发工具:

文件大小: 715kb

下载次数: 0

上传时间: 2019-08-31

提供者: wangxi*******

下载 (715kb)

不能下载？报告错误

详细说明：ARINC429总线协议又称ARINC是美国航空电子工程委员会(Airlines Electronic Engineering Committee)于1977年7月提出的，并于同年节月发表并获得批准使用。它的全称是数字式信息传输系统DITS。协议标准规定了航空电子设备及有关系统间的数字信息传输要求。ARINC429广泛应用在先进的民航客机中，如B-737、B757、B-767，俄制军用飞机也选用了类似的技术。我们与之对应的标准是HB6096-SZ-01。ARINO538日-]a■日307b17001511■ ARING HAND-HELD MICROPHONE ARINC CHARACTERISTIC 538B PUBLISHED: SEPTEMBER 21, 1981 AN ARINC DOCUMENT Prepared劬y AIRLINES ELECTRDNIC ENGINEER/HNG COMIMITTEE 即edly AERONAUTICAL RADIO, NCORPORATED 2551 RIVA ROAD. ANNAPOLIS, MARYLAND 21401 E AR工NC53凸B一B■日3071700151己3■ REPLACEMENT PAGE REVISED: February 16,1983 AERONAUTICAL RADIO, INC. 2551 Riva road Annapolis, Maryland 21401 ARINC CHARACTERISTIC 538B HANDHELD MICROPHONE ARINC Characteristic 538B-I was first published on: Prepared by the Airlines Electronic Engineering Committee Characteristic 538B Adopted by the Airlines Electronic Engineering Committeea March 13. 1981 Characteristic 538B Adopted by the Industry: August 31,1981 Characteristic 538B-l Adopted by the Airlines electronic Engineering Committee; November 4. 1982 i Date of publication will be added when " Gray CoverIl spec is reprinted PROBLEM HARD COPY ARINO538B-8■03071?05135 FOREWORD Activities of AERONAUTICAL RADIO, INC. ARINc) and the Purpose of ARINC Characteristics Aeronautical Radio, InC, is a corporation in which the United States scheduled airlines are the principal stockholders. Other stockholders include a variety of other air transport companies, aircraft manufacturers and foreign flag air lines Activities of ARINC include the operation of an extensive system of domestic and overseas aeronautical land radio stations, the fulfillment of systems requirements to accomplish ground and airborne compatibility, the allocation and assignment of frequencies to meet those needs, the coordination incident to standard airborne communications and electronics systems and the exchange of technical information ARINC sponsors the Airlines Electronic Engineering Committee(AEEC), composed of airline technical personnel. The AEEC formulates standards for electronic equipment and systems for the airlines, The establishment of Equipment Characteristics is a principal function of this Committee An ARINC Equipment Characteristic is finalized after investigation and coordi- nation with the air lines who have a requirement or anticipate a requirement, with other aircraft operators, with the Military services having similar requirements, and other interested persons. It is published as an ARinc Equipment Characteristic only when the interested airlines are in general agreement. Such publication does not commit any user or AriNC to purchase equipment so described nor does it establish or indicate recognition of the existence of an operational requirement for such equip ment, nor does it constitute endorsement of any manufacturer's product designed or built to meet the Characteristic. Further, publication of a Characteristic does not imply its endorsement by the U.S. Federal Government or any of its agencies whose representatives may have participated in its preparation. An ARINC Characteristic has a twofold purpose, which is: () To indicate to the prospective manufacturers of airline electronic equipment the considered opinion of the airline technical people, coordinated on an industry basis, concerning requisites of new equipment, and (2)To channel new equipment designs in a direction which can result in the maximum possible standardization of those physical and electrical charac teristics which influence interchangeability of equipment without seriously hampering engineering initiative. ARINO53BB-183■037日17口0015147■ ARINC CHARACTERISTIC 538B TABLE OF CONTENTS ITEM SUBJECT PAGE INTRODUCTION AND DESCRIPTION Scope and function Associated Equipment Applicable Publications I,4 Regulatory Apl MECHANICAL CONSIDERATIONS 2 2。1 Weight Protcction Preamplifier Form Factor Cord Connector 30 ELECTRICAL CHARACTERISTICS Microphone Element 2 Preamplifier Power Feed Circuitry 33,1 Distortion 3.3,2 Frequency response 3.3.3 Internal Output Impedance 3.3.4 Hum rejec Parallel Oper 22222333333334445 3.3.5 ration 3,4 Switch 3.5 36 Recommendations for Microphone Input-Circuit Standards in Future Equipment 4-Wire Microphone Interconnection ATTACHMENTS Microphone Form Factor and Stowage 2 Electrical Interface For Performance Measurements Microphone-Preamplifier Frequency Response Limits 678 A Method of Measuring the Internal outpt Microphone-Preamplifier Combination NEXT PAGE INTENTIONALLY LEFT BLANK ARINC538B-18孑■03071?00515号■ REPLACEMENT PAGE ARINC CHARACTERISTIC 538B- Page l L0 INTRODUCTION AND DESCRIPTION 1.1 Scope and Function This Characteristic describes a hand-held microphone for use with airborne radio installations, Characteristic 538B incorporates changes to the older Characteristic 538(dated March 3, 1972)and serves as a continuation and modification of the original Characteristic. Microphones of many design variations are in satisfac tory airline usage and many others are available; there- fore, this Characteristic does not preclude ticular design nor imply that the design outlined herein consti tutes the only satisfactory microphone. 1.2 Associated E quipment The microphone should include an integral preamplifier located wlthin th ophone housing. 1.3 Applicable Publications (a) ARINC Specification 403- Guidance for Designers of Airborne Electronic Eq ment. dated septe (b) RTCA Document DO-160A-Environmental Conditions and Test Procedures for Airborne Electronic/Electrical Equipment and Instru ments, dated January 1980 (c RTCA Document DO-170-Audio Systems Characteristics and Minimum Performance Standards Aircraft Microphones (Except Carbon), Aircraft Headsets and Speakers Aircraft Audio Selector Panels and Ampli- fiers, dated January 1980 The RtCa documents are not available from ariNc but may be obtained from the Radio Technical Commission for Aeronautics, Suite 655, 17 17 H Street, N W, Washington, D. C, 20006, Telephone (202)296- 0484。 ( d) AEEC Letter 64-2-47-Distribution of Draft No. 3 of Project Paper No. 412,"Audio Systems, 1.4 Regulatory Approval This equipment should meet all applicable FAa regula- tory requirements. This Characteristic does not and cannot set forth the specific requirements which an equipment manufacturer must follow to be assured of FAA approval. Such information must be obtained from FAA AR工NC53品日-1召■03717口0囗]5]5■ REPLACEMENT PAGE REVISED: February 16, 1983 ARINC CHARACTERISTIC 538B- Page 2 2.0 MECHANICAL CONSIDERATIONS 2.1 Weight 2.5 Cord (cont'd) weigh more than 8 ozs(227 grams/ plugs, should not The unit, exclusive of cables and COMMENTARY Historically, cord failure is one of the main 2.2 Protection reasons for microphone removals, Manufacturers are encouraged to pay special attention to strain The microphone design should be such as to permit relief provisions and the use of highly durable using some form of replaceable vapor shield material for the outer jacket. Solderable and crimpable low resistance teflon coated tinsel col 2.3 Preamplifier ductors should preferably be used. In addition, the use of a twisted -or, still better twisted and The preamplifier should be designed to fit within the shielded pair for the audio part is highly ream- microphone housing. mended for additional protectlon against E.M.I COMMENTARY 2.6 Connector An output level control may be included, however, The microphone cord should be terminated with an ITT this control should not be accessible from the Cannon Connector XLR_4-12 C or equivalent, e.g. Neutrix nc-4 Mce 2.4 Form Factor COMMENTARY A specific form factor is not specified, however, the Problems with connectors for this use are design of the microphone should provide for comfort generally due to incompatibility between cord able hand-held operation, easy PTT switch operation, size and strain relief provisions. Microphone and easy stowage manufacturers should pay utmost attention to this, a good example is the method used in COMMENTARY telephone handsets Two examples of microphone stowage are shown in Attachment l, but it is suggested that the airlines and manufacturers devise a single stan- dard means of stowage for any hand-held micro- phon 2.5 Cord c-1 The microphone should be supplied with a cord having the following characteristics: 1. Relaxed coil length of approximately one foot 2. Extended coil length of approximately six 3. The cord should have good physical memory characteristics 4. As an option, the audio conductors should be twisted and shielded. ARINO53凸B一凸■030751?000151?己■ REPLACEMENT PAGE REVISED: February 16,1983 ARINC CHARACTERISTIC 538B-Page 3 3.0 ELECTRICAL CHARACTERISTICS NOTE: The following characteristics do not neces 3。3. I Distortion sarily apply to microphones contained within oxygen masks. Such microphones lack com- Total harmonic distortion should not exceed 5% at the tonality with other microphones parti- specified sensitivity. cularly in their sensitivity requirement General 3.3.2 Frequency Response Unless otherwise speclfied in the following paragraphs, The frequency response of the microphone-preamplifier RTCA DO-170 Part Il, 2 and 3 should be used. combination should fall within the limits shown in Attachment 3 when tested and connected in accordance 3.1 Microphone Element with Attachment 2; the preamplifier alone should con forin with the high frequency roll-off The microphone element may be either noise-cancelling or non-noise cancelling as specified by the user, Manu- COMMENTARY facturers are referred to the recommendations mentioned in Part 1, 4.2 of RTCA DO-170. Attachment 3 differs from the performance stan- d in Do-170 Part II 1, mainly 3.2 Preamplifier Power Feed Circuitry reference level of o dB at 400 mv is shown The microphone preamplifier should derive its operating 3.3.3 Internal Output Impedance voltage as shown in attachment 2, Electrical Interface, The internal output impedance of the microphone 3.3 Sensitivity preamplifier combination should be a minimum of 150 ohr The sensitivity of the microphone -preamplifier combi- nation should be such that when connected in COMMENTARY accordance with Attachment 2, a 1000 Hz input signal at an intensity of 114 dB SPL, re: 20 uPA, provides an The classic method of determining the internal output of 400 mV RMs+ 3 dB across a load impedance output impedance of a non-powered microphone of 150 ohms. where the open-circuit voltage is measured and a resistance is measured which loads the open cir 代1 Attachment2 differs from fig。1of cuit voltage to one-half value cannot be used. It Appendix B in DO-170, only, in defining is not possible to measure the open-circuit volt- more precisely the total load impedance of age of a powered microphone-preamplifier combi- 150 ohms nation. One method of measuring the internal output impedance of the microphone -preamplifier NOTE 2: If an internal volume adjustment is used the combination is shown in Attachment 4 range of that device should be limited to+ 4dB ref, 400 mV. (See also Commentary 3.3.4 Rejection under 2.3). The induced hum"voltage should not exceed 5mv COMMENTARY when the microphone-preamplifier combination placed in a magnetic field created by 20 amperes, 400 This sensitivity requirement is more stringent Hz power, flowing in a conductor oriented to produce H c-l than that specified in Do-170. In commercial maximum hun and located 6 inches from the conbi- aviation a standard electrical interface between nation. microphones and the communication equipment is of utmost importance. Optimal depth of modula- COMMENTARY tion of transmitters had to be assured for all combinations of Line Replaceable Units, micro ARINC 538B differs from aRiNc 538A in that the phones, and black boxes. Historically the lack of distance specified between the conductor and the such a standard interface has been a problem in microphone is relaxed from 3 inches to 6 inches, oling such otherwise interchangeable equipment because of difficulties manufacturers encountered between airlines, in trying to comply with Characteristic 538A ARiNc 538B in fact now reflects the minimum Using a white noise source or a frequency sweer hum performance specified in RTCA Document generator would provide a better check of overall DO-170 Part il3.8.1. microphone sensitivity then does the above defined single tone test. However, these tests 3.3.5 Parallel Operation require complex equipment that is not rcadil available to all microphone users who may wish to When two microphones of the same type are operated verify their microphone performance. Testing the simultaneously in a parallel mode the output from icrophone output at a single frequency tells very either microphone should not fall more than 6 dB when little about the output over the speech frequency compared with the output voltage from one microphone range, However, this test in conjunction with the operated singly. frequency response test(section 3. 3. 2)should provide reasonable assurance that adequate output is available to meet the user needs. ARINC53凸B~1凸3■日307b?00151凸4■ REPLACEMENT PAGE REVISED: February 16,1983 ARINC CHARACTERISTIC 538B- Page 4 3.0 ELECTRICAL CHARACTERISTICS (contd) 3.3.5 Parallel Operation (cont'd) 3.5 Plug COMMENTARY The microphone should be supplied with an ITT Cannon Connector Type XLR-4-12C or equivalent, e.g. Neutrix In previous generations of aircraft parallel opera- NC-4 MC.. The following interconnections should be tion of microphones was used in Interphone usede systems. Later generations of aircraft generally use Interphone Amplifiers with separate inputs. Pin 1-Push-to-talk switch high Therefore the more stringent sections of ARINC 538A could be relaxed Pin 2-Push-to-talk switch return 3.4 Switch Pin 3- Integral preamplifier output and plus excitation voltage The microphone housing should contain a switch for control of the microphone and push-to-talk circuits(see Pin 4-Integral preamplifier-return Attachment 2). a suggested location for the switch is shown in Attachment 1. The switch should be con COMMENTARY structed such that the two sections of the dPSt switch are independent. The contact resistance should be no Originally an ItT Cannon XLR-5-12C or Neutrix more than 50 milliohms. The current handling NC-5 Mc was adopted based on a proposal to capability should be 1 Amp, while switching 28 VDC in shield the audio wires and carry the shield through a resistive load a separate pin However after adoption at the Spring AEEC Meeting 1981, this choice was not NOTE: In designing the PTT switch every care should be taken to ensure that accidental 5-pin connector would prevent interchangeability shorting of the keying line cannot occur, as between 538A and 538B microphones and could this may have a deleterious effect on AtC cause difficulties in connector definitions for operation, Reference is made to FAA future Characteristics pertaining to boom- Advisory Circular on this subject headsets and handsets. COMMENTARY 3.6 Recommendations for Microphone Input-Circuit Standards in Future Equipment As referred to in the note, PTT switch operation should be very reliable. Manufacturers should quipment manufacturers are encouraged to design Ec therefore take notice of the recommendations microphone input-circuits in future equipment received from the field in preparing thi according to the following standards Characteristic. (a) Supply voltages 16 VDC 1. Isolated sections for key and audio circuits. (b) AC/DC load resistance: 470 ohms (c) Input impedance: 150 ohms nominal 2. Non-butterfly construction, e.g., solid path construction from wire terminal to switch COMMENTARY contact The f the above listed standards is to 3. Self-cleaning (wiping)contacts eliminate design deficiencies in microphone input circuits which have occurred in the past. Fc-1t 4. Initial contact resistance of twenty Attachment 2 depicts one of many possible milliohms maximum。 designs which meets these requirements. Notice that the resistance from microphone pin 3 to th 5. Minimum life of 100, 000 operations at a 16 volt supply source is 470 ohms. Part or all of load rating of one amp. this 470 ohm resistance will always be part of the Ac input impedance of the circuit. Thus, 6. Provisions for mounting a do41 package NAC/DC Loan Resistance refers to the diode, on the switch, for those aircraft microphone DC load of 470 ohms and to that installations requiring key line suppression. portion of the 470 ohms which contributes to the microphone AC load impedance of 150 ohms 7. It is suggested that the PTT switch design be of such nature that the switch can be easily replaced or repaired. If a spring is a part of the switch it should be a captured spring which will not "ZING" into outer space when the microphone case disassembled.

(系统自动生成,下载前可以参看下载内容)