Bose-901II-pwr-sm维修电路原理图.pdf

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1、1998 Bose CorporationService ManualRadioFans.CN 收音机爱 好者资料库2 PROPRIETARY INFORMATIONTHIS DOCUMENT CONTAINS PROPRIETARY INFORMATION OFBOSE CORPORATION WHICH IS BEING FURNISHED ONLY FORTHE PURPOSE OF SERVICING THE IDENTIFIED BOSE PRODUCTBY AN AUTHORIZED BOSE SERVICE CENTER OR OWNER OF THE BOSE PRODUCT,

2、 AND SHALL NOT BE REPRODUCED OR USED FOR ANY OTHER PURPOSE.ContentsSafety Information. 3Specifications. 4Technical Description . 5-6Figure 1. Equalizer Controls Response Charts. 6Disassemble/Assembly Procedure .7-8Figure 2. Staple Location . 7Figure 3. Staple Removal Tool . 7Figure 4. Wiring Diagram

3、 . 7Figure 5. Top Cover. 9Figure 6. Front Panel Assembly . 9Figure 7. Indicator Lens Assembly . 9Test Procedure . 10-11Figure 8. Test Set-Up . 10Part List. 12Part List Notes. 12Figure 9. 901 I Schematic Diagram. 13Figure 10. 901 II Schematic Diagram. 14Figure 11. 901 Schematic Diagram (first product

4、ion run). 15RadioFans.CN 收音机爱 好者资料库3CAUTION: THE BOSE 901 I and II EQUALIZERS CONTAIN NO USER-SERVICEABLEPARTS. TO PREVENT WARRANTY INFRACTIONS, REFER SERVICE TO WARRANTYSERVICE STATIONS OR FACTORY SERVICE.SAFETY INFORMATION 1. Parts that have special safety characteristics are identified by the sym

5、bol on schematics or by special notes on the parts list. Use only replacement parts that have critical characteristics recommended by the manufacturer. 2. Make leakage current or resistance measurements to determine that exposed parts are acceptably insulated from the supply circuit before returning

6、 the unit to the customer. Use the following checks to perform these measurements:A. Leakage Current Hot Check-With the unit completely reassembled, plugthe AC line cord directly into a 120V AC outlet. (Do not use an isolationtransformer during this test.) Use a leakage current tester or a meterings

7、ystem that complies with American National Standards Institute (ANSI)C101.1 “Leakage Current for Appliances” and Underwriters Laboratories(UL) 1492 (71). With the unit AC switch first in the ON position, then in theOFF position, measure from a known earth ground (metal water pipe,conduit, etc.) to a

8、ll exposed metal parts of the unit (antennas, handle bracket,metal cabinet, screw heads, metallic overlays, control shafts, etc.), especiallyany exposed metal parts that offer an electrical return path to the chassis.Any current measured must not exceed 0.5 milliamp. Reverse the unit powercord plug

9、in the outlet and repeat test. ANY MEASUREMENTS NOT WITHINTHE LIMITS SPECIFIED HEREIN INDICATE A POTENTIAL SHOCK HAZ- ARD THAT MUST BE ELIMINATED BEFORE RETURNING THE UNIT TO THE CUSTOMER.B. Insulation Resistance Test Cold Check-(1) Unplug the power supply andconnect a jumper wire between the two pr

10、ongs of the plug. (2) Turn on the power switch of the unit. (3) Measure the resistance with an ohmmeter be- tween the jumpered AC plug and each exposed metallic cabinet part on the unit. When the exposed metallic part has a return path to the chassis, the reading should be between 1 and 5.2 Megohms.

11、 When there is no return path to the chassis, the reading must be “infinite”. If it is not within the limits specified, there is the possibility of a shock hazard, and the unit must be repaired and re- checked before it is returned to the customer.4SPECIFICATIONS901 Series I and II SpeakerDimensions

12、:20-9/16 W x 12-3/4 H x 12-7/8 DWeight:33 lbsNominal Impedance:8 ohmsPercentages of Direct and Reflected Sound RadiationPower radiated byreflection:89%Power radiated directly:11%Power Handling:Continuous sine wave any frequency:50 WattsMinimum amplifier power:25 WattsPeak power (less than 5 seconds)

13、:400 WattsMaximum amplifier power:270 Watts rms8 ohmsDamping Factor:Any amplifier with a damping factor of 40 or higher(must follow the speaker wire recommendation in the Owners Guide)Driver Complement:Nominal driver diameter:4-1/2Maximum driver excursion: 1/4Nominal driver impedance:8 ohmsWeight of

14、 each ceramic magnet:9.6 ounces901 Active EqualizerDimensions:2-13/16 H x 9-1/4 W x 6-3/4 DInput Impedance:150k ohmsOutput Impedance:Less than 100 ohmsMinimum LoadImpedance:5k ohmsMaximum OutputVoltage:4.0 VoltsMaximum Gain:18 dB 35 Hz5TECHNICAL DESCRIPTIONThe Bose 901 speakers represent a fundament

15、al advance in realistic home music reproduc-tion. The unique acoustic design of the speakers provide sound distribution in accurate simula-tion of live sound. The Active Equalizer provides unprecedented accuracy and control offrequency response characteristics.Each speaker contains nine high complia

16、nce, full range speakers with high energy magnets toallow large excursions without audible distortion on any program material. The speakers areacoustically coupled to eliminate audible resonances.The 901 speakers can be used with any high quality amplifier. Its efficiency enables operationwith moder

17、ately powered amplifiers, yet it can be used with the highest powered amplifiers toreproduce undistorted orchestral peaks at high volume levels.The Bose 901 Active Equalizer is a highly sophisticated electronic console containing tentransistors and more than a hundred components to equalize accurate

18、ly the stereo responsefor the effects of radiation impedances, speaker characteristics, enclosure dimensions andeven for the presence of the fashion fabric grille cloth. This equalization to flat power radiationis achieved with absolutely no audible distortion of any music or speech signals.Active e

19、qualization of the signal before the power amplifier is far superior to passive equaliza-tion after the amplifier because it avoids the need to handle high power and does not requirethe iron-core inductors that introduce distortion in passive equalizers. In addition, it is feasibleto use many more e

20、lements in an active network to provide much greater accuracy in equaliza-tion than is practical in the passive network.The Active Equalizer does much more than just equalize. In addition to providing the flatacoustic output of the Bose 901, the Active Equalizer offers the choice of nineteen additio

21、nalcontours that can be selected from the front panel. This gives the listener the flexibility toexercise his own taste in compensating for recording techniques, listening room characteristicsand the other variables described above. As an example of what is possible through activeequalization, the e

22、qualizer panel contains a switch marked BELOW 40, which reducesturntable rumble and other low frequency disturbances through a unique filter design thatprovides a uniform attenuation below 40 Hz while causing no audible deviations above 50 Hz.The rumble is removed without removing the life of the ba

23、ss along with it.6TECHNICAL DESCRIPTIONFigure 1. Equalizer Controls Response ChartsDISASSEMBLE/ASSEMBLY PROCEDURE901 Speaker Disassembly/Assembly1. Grille Removal1.1 Locate the staples that secure the frontor rear grille assembly. Refer to Figures 2and 3 for the staple placement and tool forremoving

24、 the staples.1.2 When removing the front grille assem-bly, note the placement of the cut out in thegrille backing.2. Grille Replacement2.1 Place the front grille assembly over thefront of the speaker. Note the cut out in thegrille backing, be sure to align the cut outwith the driver ( on late versio

25、ns the frontgrille assembly had two cut outs so thegrille placement would not be a factor whenreassembling the speaker). Secure usingnew staples or small finishing nails.2.2 Place the rear grille assembly on to thespeaker and secure using new staples orsmall finishing nails.3. Driver Removal3.1 Perf

26、orm procedure 1.3.2 Remove the screws that secure thedefective driver.3.3 Lift the driver out of the cabinet and cutthe speaker wire as close to the driverterminals as possible.4. Driver Replacement4.1 Connect the speaker wires to the newdriver. Refer to Figure 4 for the wire dia-gram.4.2 Place the

27、new driver and gasket intothe cabinet and secure it in place.4.3 Perform procedure 2.Figure 2. Staple LocationFigure 3. Staple Removal ToolFigure 4. Wiring DiagramFlat Blade ScrewdriverMachined to a Hook78DISASSEMBLE/ASSEMBLY PROCEDURE901 EQ Disassembly/Assembly5. PCB Removal5.1 Perform procedure 1.

28、5.2 Remove the four screws that securethe PCB to the chassis and lift the PCB out.6. PCB Replacement6.1 Place the PCB into the chassis andsecure it to the chassis.6.2 Perform procedure 2.7. Treble Control Removal7.1 Perform procedure 3.7.2 Remove the wires form the control,make note of the placement

29、 of the wires.8. Treble Control Replacement8.1 Solder the wires onto the control.8.2 Place the control into the chassis andsecure it in place.8.3 Perform procedure 4.9. Switch Removal9.1 Perform procedure 3.9.2 Remove the wires from the switch,make note of the placement of the wires.9.3 Remove the r

30、ivets that secure theswitch to the chassis, using a drill.10. Switch Replacement10.1 Secure the new switch to the chassisusing rivets or screws.10.2 Solder the wires to the switch.10.3 Perform procedure 4.Note: Refer to figures 5 and 6 for thefollowing procedures.1. Top Cover Removal1.1 Turn the uni

31、t over (top down) andremove the four screws located at each ofthe corners.1.2 Flip the unit back over and remove thetop cover.2. Top Cover Replacement2.1 Align the top cover with the front panel(there is a groove in the top cover for thefront panel to slide into).2.2 Flip the unit over and secure th

32、e topcover using the screws that had beenremoved.3. Front Panel RemovalNote: The series II EQ has a red indicatorlens. Refer to Figure 7. for removal.3.1 Perform procedure 1.3.2 Remove the treble control knob usingan Allen Wrench to loosen the set screw.3.3 Remove the nut holding the treblecontrol t

33、o the chassis.3.4 Remove the small nut on the inside ofthe chassis that secures the front panel tothe chassis.4. Front Panel Replacement4.1 Align the front panel screw with thechassis.4.2 Secure the front panel to the chassis.4.3 Secure the treble control to the chassisand replace the control knob.4

34、.4 Perform procedure 2.9901 I EQ901 II EQFigure 5. Top CoverFigure 6. Front Panel AssemblyFigure 7. Indicator Lens Assembly10TEST PROCEDURE1. Rub and Tick Test1.1 Apply a 10 Hz, 25 Volts rms signal(with the use of an amplifier) to the speakerterminals. Refer to Figure 8. No extraneousnoises such as

35、rubbing, scraping, or tickingshould be heard.2. Sweep Test2.1 Apply a 25 Volt signal, and slowlysweep the oscillator from 10 Hz to 75 Hz.There should be no loud extraneousnoises. If there are any loud buzzes ordistortion, replace any defective driver.2.2 Reduce the amplifier output to 10 Voltsand co

36、ntinue sweeping the signal from 75Hz to 15 kHz. Listen for any buzzes, rattles,and other extraneous noises. Dress anywires that might be the cause of the noise.3. Phase Test3.1 Using a 6 to 12 Volt dc supply.Connect the positive (+) wire to the positiveterminal and the negative (-) wire to thenegati

37、ve terminal on the speaker. Checkthat all drives are in phase, all driversshould move outward. If one or moredrivers move inward the wiring should bechecked. Refer to Figure 4.Figure 8. Test Set-Up901 I and II speaker Test901 I and II Equalizer Test1. Gain TestNote: The switches should be pushed in

38、atthe top and the treble contour rotary switchshould be on the dot.1.1 Apply a 200 Hz, 500 mV signal to theinput.1.2 Reference a dB meter to the inputsignal applied.1.3 Increase the input voltage to 4.25 Voltsfor the series I EQ and 5 Volts for the seriesII. The response should be 18 dB for theserie

39、s I, and 19 dB for the series II 3 dB.2. Frequency Response Test2.1 Apply a 200 Hz, 500 mV signal to theinput.2.2 Reference a dB meter to the output.2.3 Refer to the frequency response tableon the following page for the response test.11TEST PROCEDUREFrequency Response TableFrequencyBelow 40SwitchTre

40、bleDecreaseSwitchTrebleContourResponsedB901 IResponsedB901 IITolerancedB20 HzOFFOFFnormal (dot)14.8 dB19 dB3 dB20 HzONOFFnormal (dot)9 dB9.5 dB3 dB60 HzOFFOFFnormal (dot)9.2 dB9.4 dB3 dB60 HzON OFFnormal (dot)8 dB7.8 dB3 dB1 kHzOFFOFFnormal (dot).2 dB.1 dB3 dB5 kHzOFFOFFnormal (dot)2.2 dB4 dB3 dB12

41、kHzOFFOFFnormal (dot)9 dB12.3 dB3 dB12 kHzOFFONnormal (dot)6.9 dB8.1 dB3 dB12 kHzOFFOFFnumber 12.7 dB7 dB3 dB12 kHzOFFOFFnumber 23.2 dB7.8 dB3 dB12 kHzOFFOFFnumber 37.3 dB-3 dB12 kHzOFFOFFnumber 4-15.6 dB3 dB12 kHzOFFOFFnumber 512.4 dB18.5 dB3 dB20 kHzOFFOFFnormal (dot)12.9 dB13.8 dB3 dB12PART LIST9

42、01 Speaker Part ListItem NumberDescriptionPart NumberNote-Driver1033424-Grille, Front103514-034-Grille, Rear103512-034-Grille, Front , Ebony103514-024-Knurled Nut100424-1-Fuse Kit (External)108938-3901 EQ Part ListReferenceDesignatorDescriptionPartNumberNoteT1Transformer 110V, 220V1000993S5Power Swi

43、tch1003993S1, 3, 4Rocker Switch100400S2Rotary Switch100420-Lens Housing, 110V1163273-Indicator Lens103460-Front Panel100416-1Series II-Line Cord, 110V1116723-Line Cord, 220V1136083-Knob, Treble Contuor103457R110k ohm Resistor102537for 220VQ1-5, Q51-57Transistor102437-2D1, 2Diode100259-11. This part

44、is not normally available from Customer Service. Approval from the Field ServiceManager is required before ordering.2. The individual parts located on the PCB are listed in the Electrical Part List.3. This part is critical for safety purposes. Failure to use a substitute replacement withthe same safety characteristics as the recommended replacement part might create shock,fire, and or other hazards.4. These parts are no longer available.PART LIST NOTES13Figure 9. 901 I Schematic Diagram14Figure 10. 901 II Schematic DiagramFigure 11. 901 Schematic Diagram (first production run)15