Bose-502-A service manual 电路图 维修手册.pdf

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1、2005 Bose Corporation Part Number 170310 Rev. 02 Service Manual Panaray Sound System 502 Array, Bass Box and Controller 1 TABLE OF CONTENTS 1. SAFETY INFORMATION. 2 2. SPECIFICATIONS. 3 3. THEORY OF OPERATION. 6 4. EQ CURVES. 9 5. BLOCK DIAGRAM. 15 6. DISASSEMBLY/ASSEMBLY PROCEDURES. 17 7. TEST PROC

2、EDURES. 28 8. PARTS LISTS AND EXPLODED VIEWS. 34 9. SCHEMATICS AND PCB LAYOUTS. 64 CAUTION: THE PANARAY SOUND SYSTEM CONTAINS NO USER SER- VICEABLE PARTS. TO PREVENT WARRANTY INFRACTIONS, REFER SERVICING TO WARRANTY SERVICE STATIONS OR FACTORY SERVICE. PROPRIETARY INFORMATION THIS DOCUMENT CONTAINS

3、PROPRIETARY INFORMATION OF BOSE CORPORATION WHICH IS BEING FURNISHED 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. SAFETY INFORMATION 1. Parts that have speci

4、al safety characteristics are identified by the symbol 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

5、 insulated from the supply circuit before returning the unit to the customer. Use the following checks to perform these measurements: A. Leakage Current Hot Check-With the unit completely reassembled, plug the AC line cord directly into a 120V AC outlet.(Do not use an isolation transformer during th

6、is test.) Use a leakage current tester or a metering system 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 and then in OFF position, measure from a kn

7、own earth ground (metal waterpipe, conduit,etc.) to all exposed metal parts of the unit (antennas,handle bracket, metal cabinet,screwheads,metallic overlays,control shafts,etc.), especially any exposed metal parts that offer an electrical return path to the chassis. Any current measured must not exc

8、eed 0.5 milliamp. Reverse the unit power cord plug in the outlet and repeat test. ANY MEASUREMENTS NOT WITHIN THE LIMITS SPECIFIED HEREIN INDICATE A POTENTIAL SHOCK HAZARD THAT MUST BE ELIMINATED BEFORE RETURNING THE UNIT TO THE CUSTOMER. B. Insulation Resistance Test Cold Check-(1) Unplug the power

9、 supply and connect a jumper wire between the two prongs of the plug.(2)Turn on the power switch of the unit. (3) Measure the resistance with an ohmmeter between 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,

10、the reading should be between 1 and 5.2 Megohms. 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 poss- ibility of a shock hazard, and the unit must be repaired and rechecked before it is returned to the customer. 2 SPE

11、CIFICATIONS 502A SPECIFICATIONS Dimensions:23.5 H x 5.75 Wx 6.73 D (59.7x14.6x17.1 cm) Weight:15 lbs. (6.8 kg.) Transducer5-4.5 (11.4 cm) drivers Complement: Enclosure Material:High-impact polystyrene Nominal Impedance:8, 6.4 minimum Sensitivity:90 dB SPL (1W, 1m, 130 Hz-15 kHz) Maximum Acoustic112

12、dB SPL average Output:121 dB SPL peak Frequency Range:130 Hz-15 kHz Port Tuning135 Hz Frequency: Amplifier Power150-600 watts continuous into 8 (Recommended): Long-term power150 watts continuous handling: Beamwidth:120 horizontal, 70 vertical Input Connections:Parallel wired barrier strip (US/Can.)

13、Parallel wired XLR (Eur./Aus./UK/Japan) Fusing:4 ampere AGC (Buss) or 3AG (Littlefuse) 3 4 Dimensions: 31.0 H x 14.0 W x 15.5 D(78.7x 35.6x 39.4 cm) Weight: 80 lbs. (36.4 kg.) Transducer 1- 12 woofer (high power) Complement: Enclosure Material: 3/4 resin-core, vinyl wrapped Port: High-impact polysty

14、rene Nominal Impedance: 8 , 6.4 minimum Sensitivity: 90 dB SPL (1W, 1m, 55 Hz-150 Hz) Maximum Acoustic 115 dB SPL average Output: 122 dB SPL peak Frequency Range: 50 Hz-150 Hz Power Handling: 450 watts continuous Amplifier Power 450-1200 watts continuous into 8 (Recommended): Input Connections: 2 pa

15、rallel wired barrier strip (US/Can.) 2 parallel wired XLR (Eur./Aus./UK/Japan) Fusing: 7 ampere AGC (Buss) or 3AG (Littlefuse) 502C SPECIFICATIONS 502B SPECIFICATIONS SPECIFICATIONS (Continued) Dimensions:120V/Barrier 1.75 Hx19.0Wx8.75D(4.4x48.3x22.2 cm) Strip 220-240V/XLR1.75 Hx19.0Wx8.0D(4.4x48.3x

16、20.3 cm) Weight: 5.5 lbs. (2.5 kg.) Chassis material: 16 gauge steel with painted/zinc coated finish Cover plate material: Brushed aluminum,painted 5 SPECIFICATIONS (Continued) Input Connections: Balanced barrier strip (US/Can.) Balanced XLR (Eur./Aus./UK/Japan) Output Connections: Balanced barrier

17、strip (US/Can.) Balanced High frequency & Low frequency XLR (Eur./Aus./UK/Japan) Input Impedance: Balanced input,-10 dB level: 14 k Balanced input,+4 dB level: 6 k Unbalanced input (+ input used), -10 dB level: 12 k Unbalanced input (+ input used), +4 dB level: 4 k Output Impedance: 100 nominal Inpu

18、t Level: -10 dB or +4dB,selectable Output Level: 8.0 Vrms maximum into 600 Low Frequency (LF) Sum or normal Output Mode: LF Output Level: -18 dB to +3 dB,variable Crossover Frequency: 140 Hz (Bi-amp mode),Roll-off slope: -18dB/oct. THD: Midrange distortion of HF output: 0.1 % at 5 V, 600 Hz Low freq

19、uency distortion of LF output: 0.1 % at 5V, 80 Hz Output Noise: Bi-amp mode, HF outputs 90V Bi-amp mode, LF outputs 40V Passive mode, 90V Offset: All channels 15mV Power Requirements: 120 VAC,50/60 Hz, 12 watts (US/Can.) 230 VAC,50/60 Hz, 12 watts (Eur.) 100 VAC,50/60 Hz, 12 watts (Japan) 240 VAC,50

20、/60 Hz, 12 watts (Aus./UK) 6 THEORY OF OPERATION The following discussion provides an overview of 502C electrical operation. Equalization curves are referenced and are located at the end of this discussion. Additionally, the 502C block diagram and schematic should be referenced as required. 1. Diffe

21、rential Input Stage The input stage features protection against RFI (radio frequency interference), ESD (electrostatic discharge), and overvoltage. Referring to the Channel 1 circuit, R2/C1, R1/C120, R3/C2, and R9,10/C7 provide low pass filtering to reduce the possibility of RFI. Diodes D1-D4, D25,

22、and D26 provide input clamping to protect against overvoltage and ESD. Op-amp U1 amplifies the difference between the + and - input pins, and converts it to a single ended signal that drives the equalizers. Gain switch S3 selects between two gains, a high gain setting for -10dB sources and a low gai

23、n setting for +4db sources. 2. Equalizer for High Frequency Outputs Op-amps U1, U2 and U3 constitute the principal equalization for the high frequency output. Each stage makes a contribution to the total low or high frequency contouring required by the loudspeaker. Op-amp U4 (pins 12, 13 and 14) imp

24、lements a high pass filter suitable for the Full Range mode, while op-amp U4 (pins 8, 9, and 10) is selected for a high pass filter with a higher corner frequency for use in the Bi- amp mode. The circuitry is duplicated for both channels. See the high frequency equalization curves for more informati

25、on about the stage by stage response of the equalizer. 3. Output mode switch, Low frequency level control, and Normal/sum mode stage Output mode switch S2 (on the rear panel) controls op-amp summing amplifier U6 (pins 5, 6, and 7). In the normal mode, the stage is not used, and the Channel 1 and Cha

26、nnel 2 low frequency outputs pass independent, 2-channel bass to 2 bass cabinets. In the sum mode, Channels 1 and 2 are combined, and this mono bass signal appears at the Channel 1 low frequency output only. Potentiometer R126 (on the rear panel), Low Frequency Level, provides for adjustment of the

27、signal sent into the low frequency equalizer. 4. Equalizer for Low Frequency Outputs After the normal/sum stage, there is op-amp stage U7 (pins 12, 13, and 14) and op-amp equalizer stages U7 (pins 8, 9, and 10), U8 (pins 12, 13, and 14), and U8 (pins 8, 9, and 10). The equalizer provides high pass,

28、low pass, and contouring equalization. See the low frequency equalization curves for more information about the stage by stage response of the equalizer. 5. Mode switch Rotary switch S1 is located on the rear panel. It selects the four operating modes for the Panaray system. Currently, only Modes 1

29、(Full range) and 2 (Bi-Amp) are supported. 7 6. Output stage NOTE: The components mentioned in this paragraph are for the high frequency output only. The output stage is compatible with balanced signal transmission systems. Inverting op-amp stage U9 (pins 1, 2, and 3) provides the output signal. Dio

30、des D9,D10, D29 and D30 provide output clamping to protect against overvoltage and ESD. Relays K1 and K2 clamp the outputs to ground to protect against power on/off transients. When the relay is de-energized, as when the AC power is off, the outputs are clamped. About 1.2 seconds after the power is

31、turned on, the relay is energized by transistor Q1 and allows audio to pass through the controller. When the power is turned off, a fast acting detector de- energizes the relays to protect against power off transients. NOTE: In earlier production units (before August 1993), the output stage was diff

32、erential. Not only was the positive (+) output pin driven, but the negative (-) output pin was also driven (out of phase). The output stage was changed so that only the positive (+) output pin is driven, while the negative (-) output pin is connected to signal ground through a series impedance ident

33、ical to that of the positive (+) output pin. This alternative output stage design has improved characteristics into a variety of real world installation conditions. Both versions produce the same output level when received by a balanced input. 7. Power Supply The 502C uses only a nominal amount of p

34、ower. Therefore, full wave bridge rectifier Z1 and regulators U13 and U14 are all that are needed to develop the quiet, stable +/- 15 volt supply needed by the op- amps. 8. Turn On/Off Muting Circuit Relays K1 and K2 clamp the outputs and are controlled by three sections of quad comparator U15. U15

35、(pins 8, 9 and 14) drives the relay control transistor Q1 by pulling the relay-coil terminal to nearly 15 volts . This energizes the relay for normal audio operation. At power on, U15 (pins 8, 9 and 14) is prevented from energizing the relay until capacitor C152 can be charged up sufficiently. This

36、takes about 1.2 seconds, and mutes any turn-on transients. At power off, U15 (pins 2, 4, and 5) quickly detects the loss of AC power and causes Q1 to snap quickly off. This de-energizes the relay in about 100 ms, before any transients can reach the output. 9. Troubleshooting Tips If a differential o

37、utput test generator isnt available, connect the generator ground to the 502C ground terminal, and the generator hot lead to the negative (-) input terminal. Leave the positive (+) terminal unconnected. If you need to connect the 502C outputs to a single-ended (not differential) instrument, connect

38、the 502C output ground to the instrument ground, and the 502C positive (+) output terminal to the instrument hot pin. Leave the negative(-) output pin unconnected. Since the 502C is a two channel device, you can troubleshoot any problem occurring in only one channel more easily by applying the ident

39、ical signal to both Channel 1 and Channel 2 inputs and tracing stage by stage, comparing the signal as it passes through the various stages. In general, the corresponding Channel 1 and Channel 2 stages share the left and right hand sides of the respective op-amps. This makes it easier to compare the

40、 stages. 8 With a nominal AC power input voltage (100, 115, or 230, depending on the country), the AC voltages at the transformer secondary should be: between P3-1 and P3-3: 41.3 Vrms With a cold (i.e.-room temperature) power transformer, you should expect primary and secondary resistances of: For t

41、he 100 VAC version: between P2-1 and P2-2: 41.8 between P3-1 and P3-3: 6.9 For the 115 VAC version: between P2-1 and P2-2: 45.4 between P3-1 and P3-3: 6.3 For the 230/240 VAC version: between P2-1 and P2-2: 195 between P3-1 and P3-3: 7.1 Other DC voltages are of use in troubleshooting: Turn On/Off M

42、uting Circuit Typical DC voltages after 2 seconds wake up U15-1Section not used U15-2+13.5 U15-3-15.0 U15-4+.15 U15-5+3.2 U15-6Section not used U15-7Section not used U15-8+7.5 U15-9+13.5 U15-10+7.5 U15-11+9.7 U15-12-15.0 U15-13+13.5 U15-14-13.9 Q1-collector-14.7 Power Supply U13-1+26.0 U14-2-26.0 9

43、20 2002K 20K -40 -30 -20 -10 0 10 20 Response Figure 2. Low Frequency EQ Output is measured from U7 pins 7 and 8. 502C controls set as in Figure 1. Figure 1. Low Frequency EQ Output is measured from U7 pins 1 and 14. 502C controls are set at: Mode 2 (Bi-Amp), Output Mode: Normal, Low Frequency Level

44、: +3 dB, and Input Level: +4 dB. Frequency in Hz Gain in dB Frequency in Hz 202002K 20K -40 -30 -20 -10 0 10 20 Gain in dB 10 Figure 3. Low Frequency EQ Output is measured from U8 pins 1 and 14. 502C controls are set as in Figure 1. 20200 2K20K Frequency in Hz -40 -30 -20 -10 0 10 20 Gain in dB Outp

45、ut is measured from U8 pins 7 and 8. 502C controls are set as in Figure 1. Figure 4. Low Frequency EQ Frequency in Hz 202002K20K -40 -30 -20 -10 0 10 20 Gain in dB 11 Output is measured from U1 pins 7 and 8. 502C controls are set as in Figure 1. Frequency in Hz Figure 5. High Frequency EQ 20200 2K20

46、K -40 -30 -20 -10 0 10 20 30 Gain in dB Output is measured from U2 pins 1 and 14. 502C controls are set as in Figure 1. Figure 6. High Frequency EQ Frequency in Hz 202002K20K -40 -30 -20 -10 0 10 20 30 12 Output is measured from U2 pins 7 and 8. 502C controls are set as in Figure 1. Frequency in Hz 20200 2K20K -40 -30 -20 -10 0 10 20 30 Gain in dB Output is