Bose-251-Service-Manual 电路图 维修手册.pdf

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1、1 251 Environmental Speaker 256033 CAUTION: The Bose 251 Environmental Speaker contains no user serviceable parts. To prevent warranty infractions, refer servicing to warranty service centers or factory service. PROPRIETARY INFORMATION THIS DOCUMENT CONTAINS PROPRIETARY INFORMA- TION OF BOSE CORPORA

2、TION WHICH IS BEING FUR- NISHED ONLY FOR THE PURPOSE OF SERVICING THE IDENTIFIED BOSE PRODUCT BY AN AUTHORIZED BOSE SERVICE CENTER OR OWNER OF THE BOSE PRODUCT, AND SHALL NOT BE REPRODUCED OR USED FOR ANY OTHER PURPOSE. WARRANTY INFORMATION The Bose 251 Environmental Speaker is covered by a five yea

3、r transferable limited warranty. Contents Product Description.2 Disassembly/Assembly Procedures .2 Specifications.2 Disassembly/Assembly Procedures .3 Figure 1. Wiring Diagram .3 Test Procedures .4 Figure 2. Schematic Diagram.4 Part List.5 Figure 3. Exploded View.5 Packaging Part List .6 Figure 4. P

4、ackaging View .6 2 251 Environmental Speaker 256033 SPECIFICATIONS PRODUCT DESCRIPTION The Bose 251 Environmental Speaker is a premium environmental loudspeaker. Each loud- speaker contains one 5.25” environmentally resistant woofer in a two-chamber configuration, two 2.5” environmentally resistant

5、Twiddlers vertically stacked and angled for maximum horizontal dispersion and a crossover including system protection. The system is packaged with mounting brackets. DISASSEMBLY/ASSEMBLY PROCEDURES 1. Grille and Baffle Removal 1.1 Grasp the edge of the grill (5) and pull it off. 1.2 Remove the six s

6、crews (13) that secure the baffle to the cabinet and then pull off the baffle. 2. Grille and Baffle Replacement 2.1 To prevent air leaks, apply a new baffle woofer mount gasket (10). To prevent wire buzzes, insert the wires into the cabinets wire channel. Line up the baffle so that the baffles woofe

7、r mount fits into the groove in the cabinet. Replace the six screws (13) that secure the baffle to the cabinet. 2.2 Align the grille (5) with the cabinet so that the logo (6) is over the Twiddlers (2). Press the grille into place. 3. Twiddler Removal. 3.1 Perform procedure 1.1. 3.2 Remove the four s

8、crews (12) that secure the Twiddler (2) to the cabinet. 3.3 Lift the Twiddler out and cut the wires as close as possible to the wire terminal. Note: Make a note of the wiring configuration. 4. Twiddler Replacement 4.1 Referring to the note taken in 3.3, attach the wires to the Twiddler (2). (Refer t

9、o Figure 3) Transducers:One 5.25 environmental woofer per enclosure Two 2.5 environmental resistant Twiddlers per enclosure Impedance:6 Ohms nominal (4.8 Ohms minimum) 20-20 kHz Power Handling:100W (24.5 Vrms) continuous per IEC 268-5 Recommended amp/receiver power 10-200W per channel. Crossover Ass

10、embly:Crossover frequency: 250 Hz, 10% at 6 dB/octave System Protection:System protection: PTC device. Sensitivity:82 dB SPL (1W, 1M) 400 Hz octave band limited pink noise Flux Leakage:NA, not shielded; not for use near a video monitor External Dimensions:13.5 x 5.75 x 8.34 (34.3 x 14.6 x 21.2) cm W

11、eight:7.75 lb. (3.5 kg) 3 251 Environmental Speaker 256033 DISASSEMBLY/ASSEMBLY PROCEDURES 9.2 Remove the four screws (12) that secure the Twiddler panel (15) to the baffle. Pry off the panel. 9.3 Cut the wires as close as possible to the terminals of the capacitor (4). 10. Crossover Capacitor Repla

12、cement 10.1 Connect the leads of the capacitor (4) to the wires and solder the connections. The capacitor is wired in series with the woofers (1) negative terminal and the Twiddlers (2) positive terminal. Refer to Figure 1. 10.2 To prevent air leaks, replace the Twiddler panel (15) and gasket (9). L

13、ine up the Twiddler panel (15) with the cabinet and replace the four screws (12) that secure it to the baffle. (Refer to Figure 4) 4.2 Line up the Twiddler in the cabinet and replace the four screws (12) that secure the Twiddler in place. 5. Woofer Removal 5.1 Perform procedure 1. 5.2 Cut the wires

14、as close as possible to the woofers (1) wire terminal. 5.3 Remove the four screws (12) that secure the woofer to the baffle. Lift the woofer out. 6. Woofer Replacement 6.1 To prevent air leaks, apply a new gasket (11) to the woofer. Line up the woofer (1) in the baffle so that the wire terminal is f

15、acing toward the Twiddlers (2). Replace the four screws (12) that secure the woofer to the baffle. 6.2 Attach the green and black wires to the negative terminal and the red and yellow wires to the positive terminal of the woofer. 6.3 Place the foam tape gasket (10) around the edge of the baffles woo

16、fer mount where it contacts the cabinet. 7. Protection Circuit Removal 7.1 Perform procedure 1. 7.2 Cut the wires as close as possible to the leads of the polyswitch (3). 8. Protection Circuit Replacement 8.1 Connect the leads of the polyswitch (3) to the wires and solder the connections. The polysw

17、itch is wired in series with the speakers positive terminal and the woofers (1) positive terminal. Refer to Figure 2. 9. Crossover Capacitor Removal 9.1 Perform procedure 1. Figure 1. Wiring Diagram Wiring Diagram Table FromToWire Twid 1 (-)Twid 2 (+)Gray Twid 1 (+)Woofer (-)Black Twid 2 (-)Woofer (

18、+)Red Woofer (+)Terminal 1 (+)Yellow Woofer (-)Terminal 2 (-)Green 4 251 Environmental Speaker 256033 + +- + - + - - PTC Woofer Twiddlers 33uF, BP C1 Red Black Gray Green Yellow 2 1 TEST PROCEDURES 1. Woofer Rub and Tick Test 1.1 Apply a 6 Vrms, 10 Hz signal to the speaker input terminal. No extrane

19、ous noises such as rubbing, scraping or ticking should be heard. Note: To distinguish between normal suspen- sion noise and rubs or ticks, slightly displace the cone of the woofer with your fingers. If the noise can be made to go away or get worse, it is a rub or tick and the woofer should be replac

20、ed. If the noise stays the same, it is normal suspension noise and the woofer is okay. Suspension noise will not be heard with program material. 2. Air leak Test 2.1 Apply an 8 Vrms, 65 Hz signal to the speaker input terminal. 2.2 Listen for air leaks around the cabinet seams, Twiddler panel, and th

21、e woofer and Twiddler gaskets. Reposition or replace any gasket that is found to leak. Repairs made to the cabinet seam should not be visible from the exterior of the speaker. Note: A whooshing noise from the ports at approximately 65 Hz and 185 Hz is accept- able (port tuned frequencies). 3. Twiddl

22、er Phase Test 3.1 Check the wiring of the Twiddler against Figures 1 and 2. 4. Sweep Test 4.1 Apply an 8 Vrms, 10 Hz signal to the speaker input terminal. 4.2 Sweep the signal generator from 10 Hz to 5 kHz and then back to 10 Hz. 4.3 Apply a 3 Vrms, 5 kHz signal to the speaker input terminal. 4.4 Sw

23、eep the signal generator from 5 kHz to 15 kHz and then back to 5 kHz. 4.5 Listen for buzzes, rattles or other noises. Redress any wire that buzzes; replace the woofer or Twiddler if they are found to be defective. 5. Woofer Phase Test 5.1 Observing polarity, momentarily apply 8 VDC to the speaker in

24、put terminal. Note: To avoid damaging the speaker, only momentarily apply the DC voltage. 5.2 The woofer should move outward with the application of the DC voltage. Figure 2. Schematic Diagram 5 251 Environmental Speaker 256033 PART LIST Figure 3. Exploded View Item Number Description Part Number Qt

25、y 1 WOOFER, 5.25, ENVIRONMENTAL 289780-001 1 2 TWIDDLER TM, 60MM, ENVIRONMENTAL 289783-001 2 3 POLYSWITCH, 60V, 160 190348-160 1 4 33uF, 50V, BI-POLAR, ELECTROLYTIC, AX 254351 1 5 GRILLE, METAL, BLACK GRILLE, METAL, WHITE 250804-11 250804-12 1 6 LOGO, BLACK CABINET LOGO, WHITE CABINET 250806-01 2508

26、06-02 1 7 CONNECTOR, ENVIRONMENTAL, BLACK 250815-01 1 8 CONNECTOR, ENVIRONMENTAL, RED 250815-02 1 9 TWIDDLER PANEL FOAM GASKET 250807 1 10 BAFFLE WOOFER MOUNT FOAM GASKET 250808 1 11 GASKET, 134MM, RD, ADHESIVE BACKED 290315-001 1 12 SCREW, TAPP, 8-11 X .5, PAN, ASY, SQ 296495-008? 16 13 SCREW, TAPP

27、, 8-11 X 1.0 PAN, ASY, SQ 296495-016? 6 14 NUT, INSERT 250818 2 15 PANEL, SEALING, TWIDDLER 250820 1 16 GASKET, .725 ROUND 293936-001 1 17 TAPE, FILTER PORT 255910 1 17 6 251 Environmental Speaker 256033 PACKAGING PART LIST Figure 4. Packaging View Item Number DescriptionPart NumberQty 1CARTON, RSC,

28、 15.63X11.63 X 16.06 294092 1 2PACKING, END CAP, TOP2508091 3PACKING END, CAP2508101 4BAG, POLY, HDPE, 18 X 26, 1 MIL255354-0012 5CREASE SHEET 15.50 X 33.252508391 6BRACKET, ALUMINUM, BLACK BRACKET, ALUMINUM, WHITE 250819-11 250819-12 2 7KNOB, THREADED STUD, 1/4-20, BLACK KNOB, THREADED STUD, 1/4-20

29、, WHITE 250822-01 250822-02 1 pkg. of 4 8HARDWARE KIT CONSISTS OF: SCREW, DELETED ANCHOR, WALL 293240-001 - - - - 1 pkg. 8 - - 8 9FOOT, CLEAR, 250 DIAX. 085, SIX250821-061 pkg. of 6 10OWNERS MANUAL2508111 11INFO, WARRANTY, U.S.1813571 12INFO, WARRANTY, MULTIPLE LANGUAGE1814601 13 DELETED 14COMMITMEN

30、T LETTER2510011 15BAG, POLY, 14.38 x 9.87 x 2mil1033511 Service Manual 2004 Bose Corporation Bose 251 Environmental Speaker Part Number 256033 REV. 01 Specifications and Features Subject to Change Without Notice Bose Corporation The Mountain Framingham Massachusetts USA 01701 P/N 256033 REV. 01 3/2004