Crown-CE4000-pwr-sm维修电路原理图.pdf

POWER AMPLIFIER SERVICE MANUAL 130485-1 11/02 Rev. B 2002 by Crown Audio, Inc., P.O. Box 1000, Elkhart, Indiana 46515-1000 U.S.A. Telephone: 574-294-8000. Trademark Notice: Amcron and Crown are registered trademarks of Crown International. Other trademarks are the property of their respective owners. CE Series CE 4000 Some models may be exported under the name Amcron RadioFans.CN 收音机爱 好者资料库 CE 4000 Service Manual II 130485-1 Rev. B 2002 Crown Audio, Inc. 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 OR BOTTOM COVERS. NO USER SERVICEABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED SERVICE PERSON- NEL. 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 information 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 contact the Crown Technical Support Group. Mail: P.O. Box 1000 Elkhart IN 46515-1000 Shipping: Crown Factory Service 1718 W. Mishawaka Road Elkhart IN 46517 Phone: (800) 342-6939 / (574) 294-8200 FAX: (574) 294-8301 The lightning bolt tri- angle is used to alert the user to the risk of electric shock. The exclamation point trian- gle is used to alert the user to important operating or main- tenance instructions. RadioFans.CN 收音机爱 好者资料库 III CE 4000 Service Manual 2002 Crown Audio, Inc. Revision History Revision NumberDateComments Rev. A Rev. B 05-2001 11-2002 Initial Printing Added missing parts list on Page 5-76. Updated area code and mailing address on Pages 1, 2 and 7. Updated sections 3.2.4, 4.3.3, 4.3.9, 4.4.5, 4.6.1, 4.6.8, 4.7.2, 4.7.3, Figure 4.16. Added notes to pages 5-39, 5-73, 5-97. 130485-1 Rev. B CE 4000 Service Manual IV 130485-1 Rev. B 2002 Crown Audio, Inc. This page intentionally left blank V 130485-1 Rev. B CE 4000 Service Manual 2002 Crown Audio, Inc. 1 Introduction.1-1 1.1 Introduction.1-1 1.2 The CE 4000 Amplifi er.1-1 1.3 Scope.1-1 1.4 Warranty.1-1 2 Specifi cations.2-1 3 Theory of Operation .3-1 3.1 Audio Signal Path .3-1 3.1.1 Input Stage.3-1 3.1.2 Error Amplifi er.3-1 3.1.3 Modulator .3-1 3.1.4 Triangle Generator.3-2 3.1.5 Output.3-2 3.1.6 Output Filter.3-3 3.2 Protection and Control Circuitry.3-3 3.2.1 Current Monitor.3-3 3.2.2 Current Limiter.3-4 3.2.3 Display Circuitry.3-4 3.2.4 Control Circuitry.3-4 3.3 Power Supply Operation.3-5 3.3.1 Power Entry and Filtering .3-5 3.3.2 Fuse.3-5 3.3.3 Low-Voltage Supplies (Flyback).3-5 3.3.4 Turn-On Control Circuitry.3-5 3.3.5 PFC Boost Stage.3-6 3.3.6 Bridge Isolation Stage.3-6 4 Maintenance.4-1 4.1 Where to Begin .4-1 4.2 Surface Mount Technology.4-1 4.3 Disassembly for Inspection however, some important information is duplicated in this Service Manual in case the CE 4000 Reference Manual is not readily available. NOTE: THE INFORMATION IN THIS MANUAL IS INTENDED FOR USE BY AN EXPERIENCED TECHNICIAN ONLY! 1.2 The CE 4000 Amplifi er The Crown CE 4000 is a compact audio amplifi er designed for professional use, providing high-power amplification from 20 Hz20 kHz with minimum distortion. The CE 4000 features Crowns patented, award-winning BCA (Balanced Current Amplifi er) engineering, for superior power output, increased effi ciency, legendary Crown sound and extraordinary reliability. Crowns enhanced, switch-mode power supply with power factor correction allows the amplifier to be used worldwide without changing power supply components or settings. Other features include selectable on-board high-and low-pass fi lter sets, SST (System Solution Topologies) module compatibility, and a choice of dual output connectors: Speakon plus 5-way barrier block, 5-way barrier block plus binding strip, or dual Speakon. 1.3 Scope This Service Manual in intended to apply to all versions of the CE 4000 amplifi er. The Parts Listings include parts specifi c for the US version and the European version. For parts specifi c only to other versions contact the Crown Technical Support Group for help in fi nding part numbers. 1.4 Warranty Each Reference Manual contains basic policies as related to the customer. In addition, it should be stated that this service documentation is meant to be used only by properly trained 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 Reference Manual for warranty details. To fi nd the location of the nearest Authorized Warranty Service Center or to obtain instructions for receiving Crown Factory Service, please contact the Crown Technical Support Group (within North America), or your Crown/Amcron Importer (outside North America). If you are an Authorized Warranty Service Center and have ques- tions regarding the warranty of a product, please contact the Field Service Manager or the Technical Support Group. 1 Introduction CE 4000 Service Manual Introduction 1-2 130485-1 Rev. B 2002 Crown Audio, Inc. Figure 1.1 CE 4000 Front and Rear Views Specifi cations 2-1 130485-1 Rev. B CE 4000 Service Manual 2002 Crown Audio, Inc. 2 Specifi cations Note: All measurements are in Stereo mode with 8-ohm loads and an input sensitivity of 26-dB gain at 1-kHz rated power unless otherwise specifi ed. Power Output Power: Total Harmonic Distortion (THD): 1-kHz rated power, 0.5% or less THD. Intermodulation Distortion (IMD): (60 Hz and 7 kHz at 4:1) Less than 0.5% at rated power to 30 dB below rated power at 8 ohms. Damping Factor: Greater than 700 from 10 Hz to 400 Hz.* Crosstalk: Better than 50 dB below rated power, 20 Hz to 20 kHz. Common Mode Rejection (CMR): Better than 70 dB from 20 Hz to 1 kHz. DC Output Offset (Shorted Input): 10 mV. Controls 33.8-dB gain at 1.4-volt sensitivity; 26-dB gain at 3.46-volt sensitivity. Required AC Mains: 50/60Hz,100-240VAC (10%). AC Line Current, 100 Volts: 8.5 A; 120 Volts: 7.1 A; 230-240 Volts: 3.7 A; At Idle: Amp draws no more than 155 watts. AC Line Connector: 15A IEC Connector with Country Specifi c Cord and Plug. Inrush Current*: 50.86 A. Performance Frequency Response: 0.25 dB from 20 Hz to 20 kHz at 1 watt (See Figure 2.1). Phase Response: 15 degrees deviation from linear phase from 20 Hz to 20 kHz at 1 watt. Signal to Noise Ratio, A-Weighted, 20 Hz to 20 kHz: Better than 100 dB below rated 1-kHz power; CE 4000 Service Manual Specifi cations 2-2 130485-1 Rev. B 2002 Crown Audio, Inc. Figure 2.1 Typical Frequency Response Fault: Normally off, this red indicator will blink under fi ve different conditions: 1. When the amplifi er is fi rst powered up, until the unit is ready for operation. 2. If the heatsinks reach a temperature above normal working limits. 3. If the transformer thermal protection circuit is activated. 4. If amplifi er output wires develop a short-circuit. 5. If the amplifier output stage becomes non- operational. 6. If there is a problem elsewhere in the amplifi er. This circuit may be monitored remotely by plugging a simple switching circuit using an LED or other signaling device into the back-panel RJ-11 (Fault) jack. Under some conditions, the output of the amplifi er will be muted. Power: A green LED that turns on when the amplifi er has been turned on and has power. Input/Output Input Connector (standard module): One Neutrik Combo connector for each channel which features a balanced -inch (6.35-mm) phone jack and a 3-pin female XLR connector, in parallel with a barrier strip termination. Input Stage: Input is electronically balanced and employs precision 1% resistors. Input Impedance: Nominally 20 k ohms, balanced. Nominally 10 k ohms, unbalanced. Input Sensitivity: 0.775 volts or 1.4 volts for standard 1-kHz power, or fi xed 26-dB gain. Output Connectors: Three options available: Four (4) Neutrik Speakon NL4MP (mates with NL4FC) output connectors; (2) 5-way binding posts in parallel with two (2) Speakon connectors; or barrier strip outputs in parallel with two (2) 5-way binding posts. Output Signal, Stereo: Unbalanced, two-channel; Bridge-Mono:Balanced, single-channel. Channel 1 controls are active; Channel 2 should be turned down. Wiring Confi guration: (see Figure: 2.2). Protection CE 4000 amplifi ers are protected against shorted, open or mismatched loads; overloaded power supplies; excessive temperature, chain destruction phenomena, input overload damage and high- frequency blowups. They also protect loudspeakers from input/output DC, large or dangerous DC offsets and turn-on/turn-off transients. Construction Rugged steel chassis is formed into a durable package any stagehand could love. Coated with environmentally friendly powder for long life and ease of maintenance. Cooling: Three-speed proportional speed fan. Dimensions: EIA Standard 19-inch rack mount width (EIA RS-310-B), 5.25-inch (13.34-cm) height and 16.25-inch (36.56-cm) depth with additional 1-inch rear rack ears. Weight: The CE 4000 net weight is 33.3 pounds (15.1 kg). Shipping weight is 39.3 pounds. Figure 2.2 Output Pin Assignments Theory of Operation 3-1 130485-1 Rev. B CE 4000 Service Manual 2002 Crown Audio, Inc. 3 Theory of Operation WARNING: All voltages on the primary side of the flyback or bridge isolation transformers are not referenced to ground. They are referenced to the mains. When measuring these voltages with mains voltage applied, always use an isolation transformer to provide the mains voltage (and tie SMPSREF to signal ground) or use an isolated differential probe. 3.1 Audio Signal Path For the sake of simplicity, only channel one of the audio signal path is described. 3.1.1 Input Stage Signal is presented to the CE4000 through one of three connectors when using the standard input module. Each channel is outfi tted with a balanced XLR / phone jack, and a barrier strip. These connectors are wired in parallel, which allows daisy chaining when needed. The incoming shield is tied to ground through an 82-Ohm resistor (R607) in parallel with a 0.1uF cap (C605) for the purpose of inhibiting ground loop circulating currents and RFI protection. The signal is then converted from balanced to unbalanced in the Balanced Input Stage where it receives further RFI protection. Input impedance is 20k Ohm balanced and 10k Ohm unbalanced. Signal then fl ows into the Variable Gain Stage where the front panel level controls are allowed to affect the gain. The CE4000 amplifi er comes with three input sensitiv- ity selections: 0.775V, 1.4V, and fi xed 26dB gain set by a switch on the Bridge/Fault/Gain (BFG) PWA. With the gain switch (S1) in the 0.775V position, R6 sets the gain while in the 1.4V position R5 in parallel with R6 set the gain. In the 26dB position, R4 in parallel with R6 set the gain. The signal is then put under the control of a full-time compressor circuit comprised of a symmetrical window detector, a buffer amplifi er, and the gating op-amp which uses several small components to set the compressors attack and decay characteristics. These components are found on the large main PWA. The actual compressing is accomplished by an opto-isolator (U1) on the BFG PWA that affects the gain in the signal path. The signal then is passed through a series of switch- able filters that allow the signal to be low pass and high pass fi ltered at various frequencies. The switches are located at the back panel. The low pass fi lter is a fourth-order Linkwitz-Riley type and the high pass filter is a third-order Butterworth type. These switches (S3 for the low pass and S5 for the high pass) and their necessary circuitry are found on the BFG PWA. Inherent in all PWM amplifi ers is a rise in gain at higher frequencies. Because of this, a 32 kHz 7th- order Gaussian low pass fi lter has been included in the input stage of the CE4000 (on the main PWA). The Gaussian fi lter-type is unique in that it has minimal ringing and excellent phase response so even a high-order fi lter such as this one does not adversely affect the sonic excellence of the product. U111-A, -B, -C and D comprise this fi lter while U110-B and R178 form the gain calibration stage for this 7th order fi lter. 3.1.2 Error Amplifi er T