Bose-1201-1401-Series-I-II-Service-Manual 电路图 维修手册.pdf

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1、 Service Manual Part Number 122762 REV 01 1201, 1401 Series I and II Direct Reflecting Car Stereo Speaker System Model 1201 1401 Series I 1401 Series II 1998 Bose Corporation RadioFans.CN 收音机爱 好者资料库 2 Contents Electrostatic Discharge Sensitive (ESDS) Device Handling . 3 Specifications.4-5 Technical

2、Description . 6-10 Figure 1. 1401 Block Diagram. 9 Figure 2. 1401 II Block Diagram. 10 Disassembly/Assembly Procedures . 11-12 Test Procedures . 13-15 Part List Notes. 16 PCB Identification . 16 Figure 3. 1401, 1401 II, and 1201 Exploded View . 17 Figure 4. Main Part List Exploded View . 18 Main Par

3、t List. 19 Electrical Part List. 20-25 Speaker Part List. 26 Figure 5. Speaker Exploded View. 26 Technical Information . 27 Technical Information . 28 PROPRIETARY INFORMATION THIS DOCUMENT CONTAINS PROPRIETARY INFORMATION OF BOSE CORPORATION WHICH IS BEING FURNISHED ONLY FOR THE PURPOSE OF SERVICING

4、 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. CAUTION: THE BOSE 1201, 1401 SERIES I AND II CONTAIN NO USER-SERVICE- ABLE PARTS. TO PREVENT WARRANTY INFRACTIONS, REFER SERVICE TO WAR- RANTY SE

5、RVICE STATIONS OR FACTORY SERVICE. RadioFans.CN 收音机爱 好者资料库 3 This unit contains ESDS devices. We recommend the following precautions when repairing, replacing, or transporting ESDS devices: Perform work at an electrically grounded work station. Wear wrist straps that connect to the station or heel s

6、traps that connect to conductive floor mats. Avoid touching the leads or contacts of ESDS devices or PC boards even if properly grounded. Handle boards by the edges only. Transport or store ESDS devices in ESD protective bags, bins, or totes. Do not insert unpro- tected devices into materials such a

7、s plastic, polystyrene foam, clear plastic bags, bubble wrap or plastic trays. ELECTROSTATIC DISCHARGE SENSITIVE (ESDS) DEVICE HANDLING RadioFans.CN 收音机爱 好者资料库 4 SPECIFICATIONS Power Output: 1401 four channels 1201 two channels 100 Watts continuous into 0.45 Ohms 50 Watts continuous into 0.45 Ohms I

8、ndividual Amplifiers:25 Watts continuous into 0.45 Ohms resistive loads from 40 Hz to 17 kHz with less than .09% THD with 14.4 Volts DC IM Distortion:0.4% at 20 Watts output Frequency Response: 1 dB from nominal equalization curve 40 Hz to 16 kHz with the bass control centered and the spatial contro

9、l centered Separation:Not less than 40 dB above 500 Hz, spatial slide control centered Signal to Noise Ratio:Greater than 70 dB, A Weighted Sensitivity: Low Level Input: High Level Input: (1201 Input Level Adjustable) 250 mVrms for 25 Watts output at 1 kHz 2.75 Vrms for 25 Watts output at 1 kHz Powe

10、r On/Off: 1401 series I 1401 series II and 1201 Slide switch, controls power to booster and accessory power output line Remote Turn-On Capability Power Indicator: (1401 I and II only) Green LED Low Frequency Control: (1401 I and II only) Slider, 8 dB relative to nominal position in two octave band,

11、centered at approximately 170 Hz (refer to the response graphs) Spatial Control: (1401 I and II only) Slider, providing front to back speaker balance adjustment above 200 Hz Rear Panel Treble Switch: (1401 I and II only) Two position switch, 6 dB/octave relative attenuation on rear channels, beginni

12、ng at 5 kHz Rear Panel Switches and Controls: (1201 only) 1 Speaker Select Switch 1 Input Level Select Switch 1 Input Level Adjustment Pot 5 SPECIFICATIONS Power Supply Tolerance:Will operate without noticeable performance defects between 10.5 and 16.5 Volts DC Temperature Tolerance:-25 C (-13 F) to

13、 +60 C (+140 F) Dimensions: 1401 I and II 1201 10 W x 5 D x 2 1/2 H 8 1/8 W x 5 5/16 D x 1 3/4 H Weight: 1401 I and II 1201 2.4 lbs 2 lbs Speakers: 4 1/2 Driver 6 x 9 Driver 2 or 4 full range drivers 1201 or 1401 II Impedance:.45 Ohms Maximum Power: 25 Watts (1201 and 1401 II has short circuit prote

14、ction) 6 TECHNICAL DESCRIPTION Note: The following description is based on the 1401 II. The 1401 I is very similar with the exception of the short circuit protection, remote turn-on circuitry, compressor, and any reference to the use of the 6x 9 speakers. The Bose 1401 II Booster/Equalizer incorpora

15、tes unique circuitry that is different from other auto amplifier designs. We ask that you take the time to read this technical description before attempting to service the 1401, and 1401 series II, as it will aid you in the repair process. The Booster/Equalizer contains a preamplifier, equalizer, sh

16、ort circuit protection circuitry, remote turn on/off circuitry, Spatial Control, and two or four power amplifiers, each delivering 25 watts of power into 0.45 ohms. The 1401, and 1401 II are compatible with all front end radio/tape or tape player auto units having their own amplifier, or preamplifie

17、r outputs. Low level inputs connect to the output of a front end unit having preamplifier outputs. The booster will produce full output with 250 mVrms applied to the low level input connections. If the front end has only speaker outputs, the high level inputs are utilized. The input signal is reduce

18、d by the 100k resistors R52, 53, 72, 73 and then fed to the same differential amplifier as the low level input signal. The high level inputs produce full output with a 2.75 volt input signal. A differential amplifier U51 is used at the input to minimize sensitivity to alternator whine and other elec

19、trical noise. The differential amplifier feeds the equalizer. The equalization curve of the booster has been designed specifically for the drivers supplied with the units. The first section of the equalizer adjusts the mid frequencies. The signals are then fed to the network driven by U52, 53, (pins

20、 5 and 10) which provides both high frequency equalization and the bass slide control. This control provides boost or cut by approximately 8 dB centered at 170 Hz. The signal then takes two paths. One is the low frequency path. The signals from the left and right channels are summed and fed through

21、a lowpass filter. This signal is fed to U53 (pin 12), the bass equalization circuitry. The output of the U53 (pin 14), becomes a common bass buss, which feeds the low frequency information to all four power amplifiers. The second signal path is for the mid and high frequencies, which pass thorough t

22、he Spatial Control. The slider is a front to back balance control for the mid and high frequencies. This is not a fader control. The slider maintains constant and total acoustic power for any spatial setting. The spatial control allows you to shift the mid and high frequency sound image be- tween th

23、e front and rear speakers, with the sum of the power delivered to the front or rear speakers remaining the same. This allows great flexibility in compensating for the acoustic properties of various autos, vans, and trucks in which the system may be used. Also a switch- able lowpass filter, S1 (locat

24、ed on the rear of the unit) is in the second signal path. This control only affects the signal going to the rear speakers. In position I, the high frequencies going to the rear speakers are cut 6 dB/octave, starting at 5 kHz. In position II, the filter is disconnected. This control compensates for d

25、ifferent speaker placement. For example: if the rear speakers were mounted higher than the front speakers, the high frequencies from the rear speakers might sound too bright relative to the front speakers, thus the lowpass filter attenuating circuit would than be used. 7 TECHNICAL DESCRIPTION The 14

26、01II has four separate power amplifiers. Each power amplifier receives a summed signal from the common bass buss, and the mid and high frequency information from the Spatial Control slider. Using all four speakers to reproduce the bass frequencies provides full rich bass response while directing the

27、 other frequencies to the appropriate, left/right/front/back speakers, to maintain proper spatial characteristics. Each power amplifier uses a high slew rate operational amplifier (U11 left front, U21 left rear, U31 right front, U41 right rear). These ICs are the low level stage for each of the powe

28、r amplifi- ers. Pins 4 and 7 of the ICs provide out-of-phase signals to the driver transistors. The voltage across the 47 Ohm resistor attached to pin 6 of each IC is proportional to the current flowing into the driver transistors. The bias current of the driver transistors is device dependent. The

29、emitter resistor voltage (R11, 12, 21, 22, 31, 32, 41, 42) divided by .47 Ohms will give you the bias current of that transistor. The bias current should typically be 20-60 mA, with a maximum of 140 mA. The output transistors are unbiased. Therefore, the output waveform will show crossover distortio

30、n. Glitches will be visible at higher frequencies when driving a load. The distortion from these glitches is well above the range of human hearing. Power is supplied to the 1401 from the vehicles fuse block. This is fed directly to the output transistors. A network composed of R111 and C91 filters t

31、he 14.4 Vdc for all of the ICs in the unit. An 18V zener diode (D55) provides over voltage switching transient and load dump protection. U53, C92, R112, and R113 create a stable voltage that is 1/2 Vcc which is used as a 0 Volt reference for the audio signal. The turn on/off transient eliminator cir

32、cuit works in conjunction with the remote turn on and over current protection circuit. When power is applied to the 1401, the output of U52 goes high, which turns on Q63. This turns on Q15, 16, 25, 26 for the left amplifiers and Q35, 36, 45, 46 for the right amplifiers which prevents the driver and

33、power transistors of each amplifier from turning on. This eliminates a turn on thump as the amplifiers stabilize during power up. U52s output will go low after approximately three seconds, turning off Q63, which turns off Q15, 16, 25, 26, 35, 36, 45, 46 which, in turn enables the driver and output t

34、ransistors in the circuit to operate. The turn off detector is Q51 and Q52. When the 1401 is turned off, Q51 turns off, turning on Q52. This makes the gate of SCR Q62 go high, turning on the SCR. This pulls the voltage of pin 6, U52 low, causing U52 to go high, turning on the transistors Q15, 16, 25

35、, 26, 35, 36, 45, 46, which shuts off the driver and output transistors, eliminating any transients. In addition, whenQ52 goes high, it turns on Q61 And Q80 which discharges C53, the signal return capaci- tor through R142. The remote turn on detector is Q53. When voltage is applied to the remote sen

36、se line, Q53 shuts off. This makes the gate of SCR Q62 go low, turning off the SCR. This allows C52 to charge, which brings the voltage of pin 6, U52 up, causing U52 to go low, turning on the driver and output transistors. Also, when Q53 shuts off, Q61 and Q80 shuts off, allowing C53 to charge. 8 TE

37、CHNICAL DESCRIPTION The Bose 1201 Booster/Equalizer is a two speaker system similar to the 1401 II. In gen- eral, the same troubleshooting rules apply to both units. The RCA and high level inputs are the same, as well as the connectors for the power and speakers. The 1201 also has mute and short cir

38、cuit protection circuits. The 1201 has two amplifiers instead of four. The system has switchable equalization for the 4.5 driver or the new 6x 9 speakers. The equalizer attenuates frequencies above 1kHz in the 4.5 position and turns off the bass equalization in the 6x 9 position. The 1201 does not h

39、ave Spatial Control or frequency controls. A new feature for the 1201 is an input level control that provides the ability to interface with a variety of front ends. The input level control adjusts the amp gain for a power sensitivity of approximately 100-1000 mV (low level) and 1-10 Volts (high leve

40、l) to produce 25 Watts of power per channel at full output at 1 kHz. Also new in the 1201 amplifier is a compressor circuit. The compressor monitors the power amplifiers and reduces the input gain when the power amplifier begins to clip. Comprised of 1/2 of U1 and U3, U3 acts as a current controlled

41、 resistor across R109/209 whose equivalent resistance is inversely proportional to the current into pins 3/6. With no control current, U3 looks like an open circuit. As the current into pins 3/6 increases, the net resistance of R109/ 209 goes down and reduces the compressor amp gain. Control current

42、 is provided by detector/driver circuit of Q601-603. The outputs of the power amps (U4, U5, pin 6) pulses when the amp begins to clip. These pulses are detected by Q602, 603 and is filtered. The DC voltage is converted to control currents by R302, 402. The mute circuit is different than in the 1401

43、II. It contains two comparators that serve as voltage and time delay sensors. U6, pins 1-3, senses the ANT SW control voltage and goes low if the ANT SW input or supply falls below 9-10 Volts. When U6, pin 1, goes high, C510 charges through R516. When C510s voltage exceeds that of U6, pin 6, (after approximately 2.5 seconds) pin 7 goes high and unmutes the amplifier. If U6, pin 1 goes low, C510 dis- charges immediately through D501 and mutes the amplifier. During short-circuit conditions, Q503 turns on and pulls U6, pin 2, high causing pin 1 to go lo