Crownct800sm电路图.pdf

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1、Com-Tech 800 Amplifier Service Manual 1 COM-TECH 800 POWER AMPLIFIER SERVICE MANUAL K-SVCCT800 1-96 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 1

2、996 by CROWN INTERNATIONAL, INC. Model CT800B RadioFans.CN 收音机爱 好者资料库 Com-Tech 800 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 O

3、R 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 informatio

4、n 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 conta

5、ct 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 800 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 Q42751-0 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 Q42758-5 O

7、utput Module Parts List . 24 Q42889-8 Output Module Parts List . 25 Q42973-0 Output Module Parts List . 26 Q43190-0 Output Module Parts List . 27 Q42783-3 Main Module Parts List. 28 Q42920-1 Main Module Parts List. 31 Q43011-8 Main Module Parts List. 34 Q43042-3 Main Module Parts List. 37 Q43130-6 M

8、ain Module Parts List. 40 Q43239-5 Main Module Parts List. 43 RadioFans.CN 收音机爱 好者资料库 Com-Tech 800 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

9、Phone: (219) 294-8200 Toll Free: (800) 342-6939 FAX: (219) 294-8301 This 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

10、 Owners Manual is not readily available. NOTE: THE INFORMATION IN THIS MANUAL IS INTENDED FOR USE BY AN EXPERIENCED TECHNICIAN ONLY! Scope This Service Manual in intended to apply to all versions of the CT-800B amplifier including the Amcron ver- sion. The Parts Listings include parts specific for t

11、he US version and the European version (CT-800BE13). For parts specific 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, Circ

12、uit Theory, Electrical Test Procedures, Non-Module Parts Lists, and Module 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 m

13、ay be built up with different parts to create different modules. Note that 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 distorti

14、on, they feature balanced inputs with bridged and parallel monophonic capability. 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 on

15、ly by properly trained service personnel. Because most Crown products carry 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 warran

16、ty details. To find the location of the nearest Authorized Service Center 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 800 Amplifier

17、 Service Manual 5 Parts Information shipment on a C.O.D. or pre-payment (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 es

18、tablished, after which an amount due will be issued and shipment made upon 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

19、warehouse. Parts sold by the Crown Parts Department are solely for servicing 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 curren

20、t as of the date printed. Crown reserves the right to modify and improve 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-

21、mon letters used are C, D, H, M, P, and Q. The second through sixth characters 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 spa

22、ce is considered a character.) The seventh character is usually a hy- phen, 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. L

23、ength may vary from eight to twelve characters. There is still a letter 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 S

24、pecial Parts Many smaller electrical and electronic parts used by Crown 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

25、 as modules and panels are available from Crown only. Ordering Parts When 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

26、 method unless you specify otherwise. Shipments are made to and from Elkhart, 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

27、 Address: 57620 C.R. 105 Elkhart, IN USA 46517 Phone: (219) 294-8210 or: (219) 294-8211 Toll Free: (800) 342-6939 FAX: (219) 294-8301 Com-Tech 800 Amplifier Service Manual 6 Specifications Unless noted otherwise, all specifications are based on driving an 8 ohm load per channel, both channels driven

28、, the sensitivity switch in the 26dB position, the AC supply is 120VAC 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 spec

29、ifications. Power Power 8 Ohm Stereo305W/Ch 4 Ohm Stereo490W/Ch 70-V Line Stereo450W/Ch 8 Ohm Bridge Mono995W 4 Ohm Parallel Mono600W 2 Ohm Parallel Mono835W Bridge Mono, 140-V Line900W Parallel Mono, 70-V Line900W Load Impedances: Rated for 16, 8, 4, 2, Ohm, and 70- V use. Safe with all types of lo

30、ads, even totally reactive loads. AC Mains: 120VAC at 60 Hz with standard 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 Frequen

31、cy Response: 0.1dB from 20 Hz to 20 kHz at 1 Watt. Phase Response: 10 from 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

32、 kHz, increasing linearly to 0.1% at 20 kHz at 500W. I.M. Distortion: 13V 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. O

33、utput Impedance: 10 milliohms in series with 2 microhenries. Protection 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 curren

34、t Fault circuitry to mute audio. Delay of 4 seconds from turn on mutes 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. Fron

35、t Panel Controls: A front panel rocker switch used to power the amplifier 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 c

36、hannel selects between 8/4 ohm and 70-V modes. A push button circuit breaker 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.

37、 A green indicator for each channel shows the reserve energy status. If 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

38、 of output signal. Construction: Black splatter-coat steel chassis with 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, 5.25 inches high, 16 inches deep behind front

39、 mounting surface. Weight: 46 lbs, 12 oz. (21.2 kg) Com-Tech 800 Amplifier 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

40、regarding these amplifiers, refer to the applicable Technical Notes provided 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 vint

41、age to vintage (and similarities with other Crown products) the theory 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 technolo

42、gy. Air flows bot- tom to top, and front to side. Air flows a short distance 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

43、. This allows for a significantly higher thermal margin for the given 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

44、 provide stability, but Crown uses multiple nested feedback loops for 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 am

45、plifiers superior. Features specific to the Com-Tech Series include slew 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

46、rated output. Level controls are mounted on the rear panel and are of 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

47、, the packaging of this model is designed for maximum watt/price/weight/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 simplified 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 g