Crown_Com-Tech_400B_Service_Manual电路图.pdf

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1、Com-Tech 400 Amplifier Service Manual 1 COM-TECH 400 POWER AMPLIFIER SERVICE MANUAL K-SVCCT400 12-95 Com-Tech, ODEP and Crown are registered trademarks of Crown International, Inc. Mailing Address: P.O. Box 1000 Elkhart, IN U.S.A. 46515-1000 Shipping Address: 57620 C.R. 105 Elkhart, IN U.S.A. 46517

2、1995 by CROWN INTERNATIONAL, INC. Model CT400B RadioFans.CN 收音机爱 好者资料库 Com-Tech 400 Amplifier Service Manual 2 PRVENIR LE CHOC LECTRIQUE NENLEVEZ PAS LES COUVERTURES. RIEN DES PARTIES UTILES LINTRIEUR. DBRANCHER LA BORNE AVANT DOUVRIR LA MODULE EN ARRIRE. TO PREVENT ELECTRIC SHOCK DO NOT REMOVE TOP

3、OR BOTTOM COVERS. NO USER SERVICEABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED SERVICE PERSONNEL. DISCONNECT POWER CORD BEFORE REMOVING REAR INPUT MODULE TO ACCESS GAIN SWITCH. CAUTIONAVIS WARNING TO REDUCE THE RISK OF ELECTRIC SHOCK, DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE! The informati

4、on furnished in this manual does not include all of the details of design, production, or variations of the equipment. Nor does it cover every possible situation which may arise during installation, operation or maintenance. If you need special assistance beyond the scope of this manual, please cont

5、act the Crown Technical Support Group. Mail: P.O. Box 1000 Elkhart IN 46515-1000 Shipping: 57620 C.R. 105 Elkhart IN 46517 Phone: (800) 342-6939/(219) 294-8200 FAX: (219) 294-8301 RadioFans.CN 收音机爱 好者资料库 Com-Tech 400 Amplifier Service Manual 3 Table of Contents Introduction . 4 Parts Information . 5

6、 Specifications. 6 Theory . 7 Electrical Checkout Procedures. 12 Parts List (Non Module) . 16 Module and Schematic Information . 19 Q42762-7 Control Module Parts List . 20 Q43214-8 Control Module Parts List . 21 Q43242-9 Control Module Parts List . 22 Q42706-4 Display Module Parts List. 23 Q42716-3

7、Output Module Parts List . 24 Q42888-0 Output Module Parts List . 25 Q42969-8 Output Module Parts List . 26 Q43188-4 Output Module Parts List . 27 Q43012-6 Main Module Parts List. 28 Q43043-1 Main Module Parts List. 31 Q43129-8 Main Module Parts List. 34 Q43238-7 Main Module Parts List. 37 RadioFans

8、.CN 收音机爱 好者资料库 Com-Tech 400 Amplifier Service Manual 4 Crown Technical Support Group Factory Service Parts Department Mailing Address: PO Box 1000 Elkhart, IN USA 46515-1000 Shipping Address: 57620 C.R. 105 Elkhart, IN USA 46517 Phone: (219) 294-8200 Toll Free: (800) 342-6939 FAX: (219) 294-8301 Thi

9、s manual contains service information on Crown power amplifiers. It is designed to be used in conjunc- tion with the applicable Owners Manual. However, some important information is duplicated in this Ser- vice Manual in case the Owners Manual is not readily available. NOTE: THE INFORMATION IN THIS

10、MANUAL IS INTENDED FOR USE BY AN EXPERIENCED TECHNICIAN ONLY! Scope This Service Manual in intended to apply to all versions of the CT-400B amplifier including the Amcron ver- sion. The Parts Listings include parts specific for the US version and the European version (CT-400BE13). For parts specific

11、 only to other versions contact the Crown Technical Support Group for help in finding part numbers. This Service Manual includes several sections. These sections include Parts Information, Specifications, Voltage Conversion, Circuit Theory, Electrical Test Procedures, Non-Module Parts Lists, and Mod

12、ule Parts Lists. Schematics are attached. Note that com- ponent parts with circuit board comprise a complete module. Module part numbers are always associated with a specific circuit board, although an unpopulated circuit board may be built up with different parts to create different modules. Note t

13、hat Crown does not sell blank (unpopulated) circuit boards. Each of the compact audio power amplifiers are designed for professional or commercial use. Provid- ing high power amplification from 20Hz to 20KHz with minimum distortion, they feature balanced inputs with bridged and parallel monophonic c

14、apability. Specific features vary depending on model family. Warranty Each Owners Manual contains basic policies as re- lated to the customer. In addition it should be stated that this service documentation is meant to be used only by properly trained service personnel. Because most Crown products c

15、arry a 3 Year Full Warranty (including round trip shipping within the United States), all warranty service should be referred to the Crown Factory or Authorized Warranty Service Center. See the applicable Owners Manual for warranty details. To find the location of the nearest Authorized Service Cent

16、er or obtain instructions for receiving Crown Fac- tory Service please contact the Crown Technical Sup- port Group (within North America) or your Crown/ Amcron Importer (outside North America). Introduction Com-Tech 400 Amplifier Service Manual 5 Parts Information shipment on a C.O.D. or pre-payment

17、 (check or credit card) basis. Terms Normal terms are pre-paid. Net-30 Days applies to only those firms having pre-established accounts with Crown. If pre-paying, the order must be packed and weighed before a total bill can be established, after which an amount due will be issued and shipment made u

18、pon receipt of pre-payment. New parts re- turned for credit are subject to a 10% re-stocking fee, and authorization from the Crown Parts Department must be obtained before returning parts for credit. Crown is not a general parts warehouse. Parts sold by the Crown Parts Department are solely for serv

19、icing Crown/Amcron products. Part prices and availabil- ity are subject to change without notice. General Information Later sections include both mechanical and electrical parts lists for this product. The parts listed are current as of the date printed. Crown reserves the right to modify and improv

20、e its products for the benefit of its customers. Part Numbering System As of the printing of this manual, Crown is using two numbering systems. The elder system always uses eight characters. The first character is a letter. Com- mon letters used are C, D, H, M, P, and Q. The second through sixth cha

21、racters are numbers. The numbers build sequentially (for each prefix letter) as new parts are added to our parts inventory system. (In some cases there will be a space then a four character number after the prefix letter; the space is considered a character.) The seventh character is usually a hy- p

22、hen, though it may be a letter to indicate a revision or special note. The last character is called a check-digit, and is useful to Crown for internal tracking. Crown is in the process of converting to a new part number system. Length may vary from eight to twelve characters. There is still a letter

23、 prefix, then five numbers. These five numbers identify a type of part. The seventh character is a hyphen. Remaining char- acters identify the details of the type of part identified by the first part of the number. Standard and Special Parts Many smaller electrical and electronic parts used by Crown

24、 are stocked by and available from electronic supply houses. However, some electronic parts that appear to be standard are actually special. A part ordered from Crown will assure an acceptable re- placement. Structural items such as modules and panels are available from Crown only. Ordering Parts Wh

25、en ordering parts, be sure to give the product model, and include a description and part number (CPN/DPN) from the parts listing. Price quotes are available on request. Shipment Shipment will be normally made by UPS or best other method unless you specify otherwise. Shipments are made to and from El

26、khart, Indiana USA, only. Estab- lished accounts with Crown will receive shipment freight prepaid and will be billed. All others will receive Crown Parts Department Mailing Address: PO Box 1000 Elkhart, IN USA 46515-1000 Shipping Address: 57620 C.R. 105 Elkhart, IN USA 46517 Phone: (219) 294-8210 or

27、: (219) 294-8211 Toll Free: (800) 342-6939 FAX: (219) 294-8301 Com-Tech 400 Amplifier Service Manual 6 Specifications Unless noted otherwise, all specifications are based on driving an 8 ohm load per channel, both channels driven, the sensitivity switch in the 26dB position, the AC supply is 120VAC

28、at 60Hz. Crown specifications are guaranteed through the warranty period (normally 3 years). Because our testing methods are more strin- gent than our published specifications, every Crown amplifier will exceed its published specifications. Power Power 8 Ohm Stereo230W/Ch 4 Ohm Stereo255W/Ch 70-V Li

29、ne Stereo225W/Ch 8 Ohm Bridge Mono470W 4 Ohm Parallel Mono445W 2 Ohm Parallel Mono450W Bridge Mono, 140-V Line450W Parallel Mono, 70-V Line455W Load Impedances: Rated for 16, 8, 4, 2, Ohm, and 70- V use. Safe with all types of loads, even totally reactive loads. AC Mains: 120VAC at 60 Hz with standa

30、rd three-wire grounded connector for North American units; 100VAC, 120VAC, 220VAC, and 240VAC at 50 or 60 Hz units are available when ordered country specific. Com- Tech amplifiers are not voltage convertable. Performance Frequency Response: 0.1dB from 20 Hz to 20 kHz at 1 Watt. Phase Response: 10 f

31、rom 10 Hz to 20 kHz at 1 Watt. Signal to Noise Ratio: A-weighted, better than 105 dB below full rated output. Better than 100 dB below full rated output from 20 Hz to 20 kHz. Total Harmonic Distortion (THD): 0.05% from 20 Hz to 1 kHz, increasing linearly to 0.1% at 20 kHz at 500W. I.M. Distortion: 1

32、3V per microsecond. (Slew rates are limited to useful levels for ultrasonic/RF protection.) Damping Factor: 1000 from 10 Hz to 400 Hz. DC Offset: 10 millivolts. Input Impedance: Nominally 20K ohms balanced; 10K ohms unbalanced. Output Impedance: 10 milliohms in series with 2 microhenries. Protection

33、 Systems: Output Device Emulation Protec- tion (ODEP) limits drive in the event of dangerous dynamic thermal conditions without interrupting power. Current limiting for shorted load protection. DC/LF and common mode output current Fault circuitry to mute audio. Delay of 4 seconds from turn on mutes

34、amplifier to prevent dangerous turn-on transients. Mechanical Input Connectors: Balanced three-terminal barrier block for each channel on standard P.I.P.-BB module (in- cluded) Output Connectors: Four-terminal barrier block. Front Panel Controls: A front panel rocker switch used to power the amplifi

35、er on and off. Back Panel Controls: A three-position switch which selects Stereo, Bridge-Mono, or Parallel-Mono mode. A rotary potentiometer for each channel used to control output level. A two position recessed switch for each channel selects between 8/4 ohm and 70-V modes. A push button circuit br

36、eaker used to protect the power supply. Internal Controls: A three-position switch selects 0.775V, 1.4V, or 26 dB voltage gain input sensitivity. Indicators: Amber Enable indicator shows on/off status of low-voltage power supply. A green indicator for each channel shows the reserve energy status. If

37、 no reserve energy is available the indicator will dim in proportion to ODEP limiting. A yellow indicator for each channel flashes in the event of distortion. And green SPI (signal presence indicator) indicators show the presence of output signal. Construction: Black splatter-coat steel chassis with

38、 specially designed flow-through ventilation system. Mounting: Standard EIA 310 front-panel rack mount with supports for supplemental rear corner mounting. Dimensions: 19 inches wide, 3.5 inches high, 16 inches deep behind front mounting surface. Weight: 31 lbs, 12.5 oz. (14.4 kg) Com-Tech 400 Ampli

39、fier Service Manual 7 Theory Overview It should be noted that over time Crown makes im- provements and changes to their products for various reasons. This manual is up to date as of the time of writing. For additional information regarding these amplifiers, refer to the applicable Technical Notes pr

40、ovided by Crown for this product. This section of the manual explains the general opera- tion of a typical Crown power amplifier. Topics cov- ered include Front End, Grounded Bridge, and ODEP. Due to variations in design from vintage to vintage (and similarities with other Crown products) the theory

41、 of operation remains simplified. Features Com-Tech amplifiers utilize numerous Crown innova- tions including grounded bridge and ODEP technolo- gies. Cooling techniques make use of the what is essentially air conditioner technology. Air flows bot- tom to top, and front to side. Air flows a short di

42、stance across a wide heatsink. This type of air flow provides significantly better cooling than the “wind tunnel” technology used by many other manufacturers. Out- put transistors are of the metal can type rather than plastic case. This allows for a significantly higher thermal margin for the given

43、voltage and current ratings. All devices used are tested and graded to ensure maximum reliability. Another electronic tech- nique used is negative feedback. Almost all power amplifiers utilize negative feedback to control gain and provide stability, but Crown uses multiple nested feedback loops for

44、maximum stability and greatly improved damping. Most Crown amplifiers have damp- ing in excess of 1000 in the bass frequency range. This feedback, along with our compensation and ultra-low distortion output topology, make Crown amplifiers superior. Features specific to the Com-Tech Series include sl

45、ew rate limiting, and audio muting for delay or protective action. This amplifier can operate in either a Bridged or Parallel Mono mode as well as dual (stereo). A sensitivity switch allows selection of input voltage required for rated output. Level controls are mounted on the rear panel and are of

46、the rotary type. Front panel indicators let the user know the status of the low voltage power supply (enable), signal pres- ence, distortion, and an ODEP indicator for each channel which shows the reserve energy status. In general, the packaging of this model is designed for maximum watt/price/weigh

47、t/size value with user friendly features. For additional details refer to the specification section, or to the applicable Owners Manual. Front End Operation The front end is comprised of three stages: Balanced Gain Stage (BGS), Variable Gain Stage (VGS), and the Error Amp. Figure 1 shows a simplifie

48、d diagram of a typical front end with voltage amplification stages. Balanced Gain Stage (BGS) Input to the amplifier is balanced. The shield may be isolated from chassis ground by an RC network to interrupt ground loops via the Ground Lift Switch. The non-inverting (hot) side of the balanced input is fed to the non-inverti