BBK-AV215T-av-sm 电路图 维修手册.pdf

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1、 BBK AV-215T http:/monitor.espec.ws For Evaluation Only. Copyright (c) by Foxit Software Company, 2004 - 2007 Edited by Foxit PDF Editor RadioFans.CN 收音机爱 好者资料库 Chapter One Product Description AV215T (RU) is an advanced power amplifier with complete functions that adds LCD to its predecessor as well

2、 as 16 kinds of spectrum displays in the sky-blue background which makes it more extraordinary. The radio reception makes this type of device the best choice for users who are fond of radios. Its main features are as follows: 1. Built-in 5-track power amplifier that can adapt to AC-3/DTS and stereo

3、music playback. It is powerful with 80W main channel and 15W centre surround sound. 2. Mixing input interface of AC-3/DTS, VCD and DVD and DBB and stereo output interface. 3. 6-channel volume control and independent level control as well as 7-band EQ. 4. Bass Enhancer system, cyber logic and Hi-Fi p

4、layback. 5. One button for movie, music and karaoke. 6. Multiple EQ modes that adapt to different music styles. 7. Automatic spectrum analysis and compensation, automatic signal compensation. 8. Multiple spectrum display modes. 9. Complete karaoke function including microphone independent volume con

5、trol, overall volume control, pitch adjustment, voice compensation, delay and echo adjustment as well as the newly added earphone output. 10. Karaoke wide sound field function. 11. Tuning function. 12. Intelligent protection of over-current and over-voltage. Chapter Two Operating Principle Section O

6、ne Overall Structure AV215T (RU) mainly consists of the following seven parts: I. Volume Board: Select input signal source, cyber logic and bass enhancer. II. Signal Processing Board: Karaoke signal processing and 5.1CH signal amplification. III. CPU Board: Overall control, frequency point gating, a

7、utomatic circuit search. IV. Control Panel: LCD display, remote control keyboard and backlight display. V. Power Panel and Protection Circuit: Provide operating voltage required by unit circuits and overall protection. VI. Power Amplifier Board: Power amplification of 5.1CH signal or analog signal.

8、VII. Tuner: Receive radio signal and send to amplifier for signal-processing. Section Two Volume Board AV215T (RU) has four input modes: Radio input, VCD, DVD and 5.1CH. The cyber logic function of AV215T (RU) is to get C/SR/SL/SW track signals by sampling from L/R track and then processing through

9、low-pass filter and adder subtractor. Mode RadioFans.CN 收音机爱 好者资料库 switch is achieved by using electronic analog switch. The signal flow chart is as follows: I. Input selection and sound field processing mode The input selection of AV215T (RU) is achieved via electronic switches CD4052 and CD4053, t

10、he truth tables of which are as follows: CD4052 Truth Table CD4053 Truth Table TunerVCD DVD 5.1 A X B Y C Z A 0 0 1 1 0 X0 0 Y0 0 Z0 B 0 1 0 1 1 X1 1 Y1 1 Z1 5.1CH input mode: Now A/B/5.1CH control pins of M62446 are of high level. L/R N108B S-C CD 4053 Electro nic switch N103 S-SL S-SR Tuner CD405

11、2 Electronic switch N1015.1CH VCD DVD N106 M62446 R L CD 4053 Electro nic switch N104A N104B N107B N105B N105A N107A SR S-C C SL SWIN SW DISPLY OUT RadioFans.CN 收音机爱 好者资料库 track signal of 5.1 input is outputted from pin 3/13 of N101 and sent to IC N106 for volume and tone adjustment; meanwhile, C/SR

12、/SL signal on 5.1 input terminal is respectively sent from pin 14/15/4 output of N410 to IC N106 for independent volume adjustment. And SW signal is outputted via pin 4 of N103 and then send to M62446 after being amplified by N107A. Three analog input modes: AV215T (RU) totally has three analog inpu

13、t modes: Tuner receiving signal/VCD/DVD, which are controlled via A/B signal respectively (see details in truth tables). AV215T (RU) totally has three sound field modes: standard sound field, cyber logic and Hi-Fi. 1. Standard sound field: Under overall CPU control, when bass enhancer is off, L/R ch

14、annel and subwoofer output are available; when bass enhancer is on, only L/R channel output is available. 2. Hi-fi: Under overall CPU control, only L/R tracks output is available to M62446; 3. Cyber logic: Pin 9/10 of electronic switch N101 (CD4052) select a series of analog L/R track input signals

15、according to the truth table. L/R signals are outputted from pin 13/3 via the internal electronic switch of N101, and divided into two ways. One way is respectively sent into pin 13/15 of M62446, for electronic volume and tone control. The other way produces SW/S-SR/S-SL/S-C signals via buffer, adde

16、r-subtractor and low-pass filter. SW/S-SR/S-SL signals are sent to pin 12/2/5 of N102. N102 select cyber logic signal input (see truth table of CD4053) from cyber logic and 5.1CH signals, outputs C/SR/SL signals and sends into pin 11/8/9 of M62446 for volume control. Still another way of SW signal d

17、irectly sends to pin 6 of M62446 after being outputted from N107A. 5.1CH signal sent into M62446 is outputted from pin 31-36 after volume and tone control, and then outputted to signal board by XS20 power distributor. The relation between sound sources in input circuit and sound processing modes is

18、as illustrated below. II. Control circuit Pin 23/26/27 of CPU (N100) output data, PVST and clock signal and send to pin 39/40/41 of M62446 to control pin 1/2/3/4 of M62446 to output control level, so as to select input signal and spectrum sampling signal. It is worth noting that PVST signal is a lat

19、ch control signal. When data and clock of CPU are sent to M62446, an identification signal will be added, indicating that this signal can only be used by M62446 while other IC of I2C bus cannot use current data and clock signal. III. Frequency spectrum sampling circuit Only S-C/S-SR/S-SL/SW signals

20、are sampled during frequency spectrum sampling in AV215T （RU） and added to pin 14 via a 150K sampling resistance. Another S-C cyber logic signal is added to pin 1 of N103, called S-C. 5.1CH and LR-T of M62446 select sampling signals. When cyber logic is selected, the control signal of 5.1CH is of lo

21、w level while pin 9/11 of N103 is of low level. According to the truth table, it is known that the outputs are X0/Z0. Sampling signal is grounded while LR-T is of H level. Select Y1, S-Csignal is outputted from pin 15 of N103 to N108B, adding to OK-R signal for the amplification of frequency spectru

22、m signal, and then sent to frequency point gating and auto search circuits. . Tuning function This device has the tuning function which provides users a good functional option. It directly controls radio-head and receives audio frequency signal mainly via CPU and then outputs after amplified via pow

23、er amplifier. The clock and data line of radio-head are shared with LM62446 and the other two control lines are connected to CPU directly. L, R signal processed by radio-head can be sent to N101 IC CD4052 directly to input the selected track. Section Three Signal Processing Board The signal processi

24、ng board superposes, mixes and amplifies 5.1CH signal sent from the volume board, voice signals from the voice board and karaoke signal. I. AV215T（RU）Karaoke Circuit 1. Function: this circuit processes human voice through power amplifier and reproduces it via speaker. It includes human voice beautif

25、ication circuit, wide sound field processing circuit, karaoke echo and delay adjusting circuit. Press INPUT button to circularly select Two analog input modes 5.1 input mode Hi-fi mode Standard sound field Cyber logic L/R channel output only. Sound filed and EQ setup not available. L/R/SW output onl

26、y. Concert hall sound filed and EQ setup available 6CH output. Theater sound filed and EQ setup available 6CH output. Theater sound filed and EQ setup available IC and its functions for karaoke IC serial number Name of IC Functions N201 4558 Transmittal. Preamplification for karaoke signal N200 PT23

27、15 Volume control of karaoke, including tone control N205 CD4053 Electronic switch N209 PT2399 Karaoke echo processing N207 CD4051 Karaoke delay adjustment N208 CD4051 Karaoke echo control N204 4558 Phase inverter PT2315 functional pin S/N Name of pin Description Remarks 1 REF Reference voltage (1/2

28、VDD) 2 VDD Power supply 3 AGND Analog 4 TREB L 5 TREB R L/R channel treble control pins 6 RIN R channel input 7 LOUD-R R channel loudness control pin 9 LOUD-L L channel loudness control pin 11 LIN L channel input 12 BIN L 13 BOUT L L channel bass control input/output pin 14 BIN R 15 BOUT R R channel

29、 bass control input/output pin 16 RFOUT R channel output 17 LFOUT L channel output 18 DGND Digital 19 DATA （DATA）control data of sequence transmission (DATA) 20 LCK Clock input of sequence transmission 8，10 NC Not connected 3 3. Flow chart of karaoke signal When the microphone is inserted, MIC signa

30、l is sent via MIC to the transmittal circuit combined by N201A for amplification. Amplified MIC signal gives CPU a MIC identification signal after N202A amplification, followed by VD201 rectification and filtering control triode V200. CPU sends PKM signal, which is of low level, causing cutoff of tr

31、iode V103/V105 and enabling output of MIC signal; another way reaches pin 6/11 of PT2315 after C219/C222 coupling, outputs from pin 16/17 after internal volume and tone control, mixed into one way and sent to N202B and then reversely send to N203B for amplification. Signals amplified by N203B are di

32、vided into two ways. One way is directly outputted. The other way is outputted from pin 14 after being coupled by R222/C247 to PT2399 for internal delayed reverberation adjustment, reversed by N204 and outputted by mixing with karaoke signal. While OK-R is outputted from pin 14 after being gated by

33、N205 and superposed to L/R track. In this circuit, the bass boost network made up of triode V201 connected to the negative terminal of N202B is primarily for bass boost of 75HZ low frequency signal. During delay adjustment for PT2399, first control signal is given to CPU, which controls N207 after b

34、eing expanded via N211 IC CD4049 and connects with pin 6 of PT2399 by selecting different resistance values for purpose of delay adjustment. Reverberation control is to change the resistance value at the connection point to R229, so as to change the superposition on through connect signal for reverb

35、eration control. The broadband processing control signal of SOKs karaoke is in broadband mode when it is of high level, when the signal of OK-R is the OK signal inverted by N204A. A sense signal of OK-SW on the MIC plug conducts MIC signal detection together with the network made up of V200. When MI

36、C is not plugged, it is of low signal; when plugged, it is of high signal. Karaoke auto mute is also available. When P-KT fails to detect signal for a continuous time, CPU will send a P-KM signal to mute karaoke and avoid MIC receiving noise, which may affect on sound effect. ? Signal flow chart of

37、profiles MIC N201 N200 N202 B N203BN209 N204 N205 N207 N208 N100 Karaoke mixed output N202 A V200 CP Pass AV215T (RU) has a special function that switching between 5 profiles is available without karaoke. Its flow chart is as follows: When pin 9/10 are of high level, sampled L/R/C signals are output

38、ted via pin 3 N205 gating, and sent to the internal of PT2399 after amplification by N203B for reverberation delay adjustment (by IC CD4049), and then superposed to L/R/C track to form different profiles. In this circuit, MIC shall not be inserted and is only available in 5.1CH mode. N203A is for th

39、e purpose of reversal. In addition, this device is added earphone output function. PHSW is low level and each track has output when earphone is not inserted. But when earphone is inserted, PHSW will be high level for the mechanical settings thus LRM and SCM signal change into high level at the same

40、time and realize muting in each track, so the signal is only outputted from earphone, i.e. there is no signal output with each track when connecting with earphone output. II. Bass enhancer circuit P-BURST is the switch signal of burst driver. When it is of high level and added to the base electrode

41、of V102, V102 will be switched into conduction. When the collector electrode outputs low level, V107 will be cut off; when the collector electrode is of low level, V107 will also be cut off. SW signal is normally outputted to external terminal. Meanwhile, the high level signal of P-BURST is added to

42、 the emitter electrode of V108. V108 is positively biased and switched into conduction. The collector electrode adds high level to the base electrode of V101. V101 is positively biased and switched into conduction, CD4094 N205 N203 B N209 N207 N208 N204 B Mixed output N204 A and ground SW signal, no

43、t superposing it to L/R track signal. In reverse, when P-BURST is of high level, V100 will be switched into conduction and SWM signal cannot be outputted from external terminal. Meanwhile, V101 is cut off and SW signal is superposed to L/R track signal. The burst driver of AV215T (RU) can be divided

44、 into three steps. This principle is to change the volume of burst driver by changing the SW output volume of M62446. Meanwhile, SWM signal is added to relay via XS9. When the relay is off, SW signal will be grounded, disabling the output at super bass port. III. Mixing and amplification circuit of

45、5.1 signal and karaoke When L/R track signal of 5.1 signal is superposed with SW signal and amplified by N101B/N100B, it is sent to the reverse phases of N101A/N100A. Meanwhile, OK-R/OK-L signals are also respectively added to the reverse phases of N101A/N100A. After mixing and amplification by N101

46、A/N100A, they are outputted respectively from pin 1 of N100A/N101A to power amplification circuit for power amplification. Meanwhile, the C-1 signal sent by volume board is added to the reverse phase of pin 6 of N102B and added to the reverse phase of N102A after amplification. Now C1-1 signal after

47、 electronic reverberation processing is also added to the reverse phase of N102A and sent to power amplification circuit after mixing and amplification. SR-1/SL-1 of another volume board is also added to the reverse phases of N103B and N104B for amplification and then sent to N103A and N104A for fur

48、ther amplification, and later sent to power amplification circuit. One way of 5.1 signal being mixed and amplified is sent to power amplification circuit passing through XS9, and the other way forms DIST (distortion error detecting signal) signal passing through R111-R113/R142/R145/VD100-VD104, whic

49、h will be added to CPU for automatic gain, so as to control volume output. Section Four CPU Board Achieve overall control, automatically search input signal and analyze spectrum 1. CPU Overall Control N100, the overall CPU, is the overall control center, inputting all kinds of control instructions to controlled circuits to achieve all kinds of control functions. It adopts +5