Arcam-T51-tun-sm维修电路原理图.pdf

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1、T51 DiVA T51 AM/FM Tuner Service Manual ARCAM Issue 1.0 RadioFans.CN 收音机爱 好者资料库 Contents List ! Contents list ! Circuit description ! Circuit diagrams ! Component overlays ! Circuit board parts list ! General assembly parts list RadioFans.CN 收音机爱 好者资料库 T51 Tuner Circuit Description Power Supply Main

2、s voltage selection is made by placing a fuse, of appropriate value, in the 115V or 230V position. The single secondary is rectified and regulated and supplies four regulators. Z7 is always powered when the mains is connected and keeps the preset memory of the micro controller intact. The high-value

3、 capacitor (C84) will keep this data safe, for a limited time, in case of mains power failure. Z5 provides the main 12V supply rail for the RF and audio circuits. This is always connected, except for the supply to the FM front end, which is disabled by Q2 when the unit is turned off. Z4 powers the L

4、ED back light on the display PCB. Z6 is the 5V digital supply for the micro controller. FM Tuner & IF The FM aerial input is mixed in the front end FE1 which provides a 10.7MHz IF output. This is filtered and amplified by ceramic filters CF1 & CF2 and the circuit based around Q9 & Q10. A third filte

5、r CF3 can be put in circuit by fitting jumpers JP1 & JP2 across pins 2 & 4 and 1 & 3 of SK6 respectively. This effectively narrows the IF band to improve selectivity. Transistors Q17 and Q21 are part of the AGC circuit. The position of the jumper link JP7 to either SK10 or SK11 determines from which

6、 point the AGC circuit is triggered. The default is for the jumper to be fitted to SK10 which minimizes cross modulation and prevents the IF amp becoming saturated. The LA1266 (Z9) demodulates the IF at pin 1 into an audio output at pin 12. The quadrature coil is a double-tuned device for best disto

7、rtion performance. When a station is tuned correctly the On Tune signal goes low and drives a green LED on the display PCB. This signal is also used by the auto-stop detection and muting circuits. AM Tuner & IF The LA1266 (Z9) contains the AM RF amplifier, oscillator and mixer circuitry. Switching b

8、etween FM and AM modes is controlled by the FM signal from the micro controller which disables the AM circuitry of Z9 and switches the path of the audio signal through Z8. MW/LW switching is performed by switching transistors Q12, Q14 & Q15. Each band has its own oscillator and aerial tuning coils,

9、tuned by a varicap diode all contained within the AM module L5. The 450kHz IF signal is filtered by coil and ceramic filter combination T5. Birdie Filter The Birdie Filter (L2) is a four pole low pass filter, flat to about 53kHz, then with a very steep roll off from then on. This is designed to redu

10、ce co-channel interference in FM Stereo and cut down on irritating birdie noises. Stereo Decoder Stereo decoding is performed by LA3401 (Z8). The 38kHz reference signal is accurately created by ceramic resonator X3 and does not require adjustment. Stereo separation is adjusted for maximum by preset

11、RV1. This IC also contains FM/AM audio switching and muting functions. Audio Filters & Output The left and right channel audio outputs from Z8 are filtered by the de-emphasis network of R1, C1 etc. The correct de-emphasis network is selected by the position of jumpers JP3 & JP4 on the pins of SK8. C

12、2 & C102 (220pF) are selected for 50us and C3 & C103 (560pF) for 75us de-emphasis. The final filter, based on Z3, is a two-pole low-pass circuit with a cut-off frequency of around 20kHz. Also included is a 19kHz notch filter, L1 & C4, that removes most of the residual pilot tone. Muting When the pow

13、er switch is turned off Q5 is switched off, enabling the mute circuitry of the stereo decoder (Z8) via diode D9. This removes the need for output muting transistors and eliminates switching clicks and pops. At switch-on the mute is enabled while C21 is charged via Z8. In normal use the mute inside Z

14、8 is enabled in three other ways: The AMUTE signal from the micro controller is active at power-on and for a short time when a preset is changed. When the band is changed the output is muted by charging C52. The audio output must be muted whenever the tuner is in stereo mode and is also off-tune. Th

15、is is to eliminate noise during tuning and is provided by Q8 and the MONO and OFF TUNE control signals. In Mono mode this mute is disabled so that weak stations can be heard, despite the noise. Micro controller Control of the DiVA T51 tuner is performed by a single micro controller Z10, LA7230. This

16、 also provides keypad input and drives a LCD directly. At power-on a matrix of diodes is scanned to set-up the controller for the correct options: D7 selects the correct frequency ranges. D10 enables the use of Auto tuning as well as manual tuning. D8 allows the Auto-tuning mode to use the IF Count

17、method of searching. The position of jumpers JP 5 & JP6 fitted to SK9 are used to disable or enable LW and also whether the AM band steps are 9 kHz (UK) or 10 kHz (USA). Z10 provides control signal outputs for the following functions: MONO - To defeat the stereo decoder AMUTE - Turns on the mute cir

18、cuit when a button is pressed & during tuning. FM, MW & LW - Only one output active low at any one time. Used to switch on specific parts of the RF circuitry as appropriate. The micro controller includes a Phase-Locked-Loop (PLL) circuit which compares the tuner local oscillator signals (FMIN & AMIN

19、) with a reference frequency. Based on this information and the required tuned frequency the controller varies the tuning voltage to the FM and AM front ends. The tuning voltages (FMVt & AMVt) have to be filtered from the PLL by the circuitry around Q7 & Q13. Display PCB The display PCB holds the ke

20、ypad, LCD display, LED back light module and On-Tune indicator. The remote control receiver consists of the receiver RX1 and the PIC micro controller, Z1, which is used to decode the incoming remote control codes from RC5 format to Sanyo type commands. This is because the Sanyo micro controller, Z10

21、, can only respond to Sanyo remote control commands. Jumper Settings Jumper Option 1 Option 2 JP1 Best sensitivity Best sound JP2 Best sensitivity Best sound JP3 De-emphasis 50uS De-emphasis 75uS JP4 De-emphasis 50uS De-emphasis 75uS JP5 LW & MW MW only JP6 AM spacing 9KHz AM spacing 10KHz JP7 Less

22、X-MOD Less De-sense USA / Rest of the World If the T51 is transferred from or to the USA the following jumper settings will require changing. Jumper Rest of the World USA Action JP3 50uS 75uS De-emphasis JP4 50uS 75uS De-emphasis JP6 9KHz 10KHz AM spacing 12345678 A B C D 87654321 D C B A ISSUE DRAW

23、ING NO. DRAWING TITLE Drawn by: DATE Filename ECO No.DESCRIPTION OF CHANGE G:DATAECOECO AGENDA00_1078 L892 T51 TUNERL892_1L892_1.ddb - L892c1_1_2.prj A & R Cambridge Ltd. Pembroke Avenue Denny Industrial Centre Waterbeach Cambridge CB5 9PB T51 Tuner Circuit Diagram L892CT CL12-Sep-2000 INITIALS Date

24、 Printed 14Sheetof Notes: LK18 LK19 LK20 LK22 LK23 LK24 LK25 LK26 LK27 LK28 LK29 LK30 LK31 LK32 LK33 LK34 LK35 LK36 LK37 LK38 LK39 LK40 LK41 LK43 LK44 LK45 LK46 LK47 LK48 LK49 LK50 LK51 LK52 LK53 LK54 Tie Cable EL10 CABLE_TIE F3 T100MASP Kit Mask Exclude NF parts from kit mask, i.e. Not Fitted. This

25、 applies to R4 and R104 PCB PCB L892PB_1 Detail Drilling DD1 DRILL_DWG Paper Marker A2 Vertical DD2 DD_A2V Paper Marker A2 Horizontal DD3 DD_A2H PD1 TOOLING PD2 TOOLING PD3 TOOLING PD4 TOOLING FIX1FIX2FIX3FIX4FIX5 FIX6FIX7FIX8 Tooling & Fixing Holes Tooling Holes Main PCB Fixing Holes LCTR HCTR SD A

26、MIN IFCNT FM LW ON TUNE FM Audio AM Audio FMVt AMVt OFF TUNE Power Mute LO SCAN FM/AM IF Demodulator L892C2_1_2.SCH FM Audio AM Audio FM AMUTEOFF TUNE MONO STEREO Power Mute PICMUTE Stereo decoder and Audio L892C3_1_2.SCH AMIN FMVt AMVt HCTR LCTR STEREO FM LW MONO IFCNT AMUTE SD ON TUNE LO MW PICMUT

27、E SCAN Microprocessor and PLL L892C4_1_2.SCH Photo Strip PS PHOTO_STRIP CEM1, 2 OZ Cu PCB MATERIAL DD4 CEM1_20Z Photo Block PHOTO_BLOCK LK55 LK56 LK57 1 LK58 LK59 LK60 Update Box EL1 UPDATE_BOX CL17/7/00PRODUCTION RELEASE00-1044 1.200_1078CL12/09/00R93 WAS 220R NOW 1K0 12345678 A B C D 87654321 D C

28、B A ISSUE DRAWING NO. DRAWING TITLE Drawn by: DATE Filename ECO No.DESCRIPTION OF CHANGE G:DATAECOECO AGENDA00_1078 L892 T51 TUNERL892_1L892_1.ddb - L892C2_1_2.SCH A & R Cambridge Ltd. Pembroke Avenue Denny Industrial Centre Waterbeach Cambridge CB5 9PB T51 Tuner Circuit Diagram L892CT CAH/SJB 12-Se

29、p-2000 INITIALS Date Printed 24Sheetof 1 2 SK10 2WVERTJUMPER CF3 SFE10.7MLA FM I/P 1 2 3 GND 4 Quad 1 5 Quad 2 6 Vcc 7 On Tune 8 AFC 9 FM IF 10 AM IF 11 FM O/P 12 STRQ 13 14 AM O/P 15 S meter 16 AM adj 17 IF in 18 AGC 19 IF out 20 AM I/P 21 Reg 22 Osc 23 AM Osc 24 Z9 LA1266 CF1 SFE10.7MLA R66 220R M

30、F C38 10N CD R71 330R MF Q9 BC549B Q10 BC557B C4547N CD C46 47N CD C69 100P CD C70 100P CD R77 15K MF R52 22R MF R55 22K MF R78 22K MF + C10 100U EL C14 10N CD P12V R46 10R FU + C22 10U EL C47 47N CD LCTR HCTR SD AMIN C65 1N0 CD +C23 10U EL IFCNT P12V R47 10R FU + C24 10U EL C30 10N CD C48 47N CD C4

31、9 47N CD R16 22K MF C50 47N CD R79 5K1 MF + C53 1U0 EL + C54 1U0 EL R44 68K MF Q3 BC557B P12V R37 4K7 MF FM LW R38 4K7 MF Q11 BC547B Low = AM ON TUNE R80 1K0 MF R17 10K MF +C55 1U0 EL To On-Tune LED on display R75 1K2 MF C86 100P PP FM Audio AM Audio R69 18K MF FMVt FM Gnd AM R87 4K7 MF P12V T5AM_IF

32、T AMVt A_FMRF A_AMRF A_FMGND A_FMLO A_AMLO A_FMVT A_AMVT A_ONTUNE A_FMAUD A_AMAUD A_SMETER A_FMBIRD A F OFF TUNE R68 4K7 MF P5V Q19 BC557B R92 4K7 MF P5V Q2 BC557B Q6 BC547B R10 10K MF R25 10K MF Power Mute R94 4K7 MF C42 22P CD TP7 TP6 ! ! LO A_AMSIG1 A_AMSIG2 A_AMSIG3 R40 100K MF R53 100K MF R29 1

33、0K MF R24 2K7 MF R28 2K7 MF R43 2K7 MF 1 2 3 4 5 6 7 8 Birdie Filter L2 BIRDIE IF Out 7 Gnd 4 LO Out 8 V Tune 5 Vcc 6 Gnd 3 Gnd 2 Ant 1 Case FE1 MITSUMI_FE 16 4 Can 3 2 L3 QUAD_COIL_A 43 1 Can 6 2 L4 QUAD_COIL_B R56 5K6 MF R58 100K MF C85 10N CD R19 6K8 MF CF2 SFE10.7MLA SK7 FMAMANT2 4A 1A 3A 6A 2A

34、1B 2B 3B4B 5A 6B 1C 2C 3C 13 2 1D 2D 3D4D 5D 6D 4C 6C 8 8 9 9 5 5 6 6 4 4 7 7 Cans L5 AM_MODULE R20 10K MF C66 680P PP + C31 10U EL + C25 10U EL B A_IFOUT A_FMIN A_LW A_AMGND R57 220R MF C34 10P CD Q15 BC547B Q14 BC547B Q12 BC547B + C26 1U0 EL C39 100N PC C27 100N PC 12 34 56 SK6DIL6 VPLG C67 47P CD

35、 JP1 JUMPER JP2 JUMPER Link 1&3, 2&4 for best sound quality, Link 3&5, 4&6 for best selectivity. D24 1N4148 C28 10N CD R15 390R MF R51 10K MF Q17 ZVNL120 D25 1N4148 D26 1N4148 C4110N CD R73 1M0 MF C4310N CD R76 330R MF R81 330R MF C63 10N CD Q21 J112 R83 1K0 MF D27 1N4148 R72 1K2 MF SCAN Mount Close

36、 to L3 AGC R84 47K MF R85 3K3 MF C71 1N3 PP FMCENTRE TP9 JP7 JUMPER 1 2 SK11 2WVERTJUMPER Fit JP7 to SK10 for less cross-mod, Fit JP7 to SK11 for less de-sensing. 1 + C73 100U EL R88 4K7 MF C75 1N0 CD C76 1N0 CD R89 10R MF 00_1044MGM31/7/00INITIAL RELEASE R70 68R MF R67 820R MF R93 1K0 MF 1.200_1078

37、CL12/09/00R93 WAS 220R NOW 1K0 12345678 A B C D 87654321 D C B A ISSUE DRAWING NO. DRAWING TITLE Drawn by: DATE Filename ECO No.DESCRIPTION OF CHANGE G:DATAECOECO AGENDA00_1078 L892 T51 TUNERL892_1L892_1.ddb - L892C3_1_2.SCH A & R Cambridge Ltd. Pembroke Avenue Denny Industrial Centre Waterbeach Cam

38、bridge CB5 9PB T51Tuner Circuit Diagram L892CT CAH/SJB 12-Sep-2000 INITIALS Date Printed 34Sheetof R30 4K7 MF R31 4K7 MF R33 4K7 MF R41 5K6 MF C35 470N PE C36 470N PE + C74 100U EL C29 10N CD + C51 1U0 EL Q1 BC557B Q4 BC547B + C16 10U EL C56 1N0 PP R1 91K MF R101 91K MF R45 10R FU Vin I GND G Vout O

39、 Z67805 Vin I GND G Vout O Z57812 + C58 3M3 EL +C72 100U EL +C20 100U EL +C18 100U EL Vin I GND G Vout O Z7 7805 D22 1N4003F +C68 100U EL P5V P5V6 P12V VBL Audio & RF Power Supply Backlight Power Supply Digital Power Supply Back-up Power Supply C591N0 CDC601N0 CD C611N0 CD C62 1N0 CD NL SK5 IEC2 Vcc

40、 22 AM I/P 1 Comp O/P 3 L Out 5 L F/B 6 R F/B 7 R Out 8 Vee 12 ST LED 13 16 17 Sep Adj 4 PLL 18 20 19 X in 21 FM/AM 10 Mute I/P 15 Power Mute 9 FM I/P 2 Band mute 14 Mute O/P 11 Z8 LA3401 X3 CSB456 3 2 1 Z3A NJM2114 5 6 7 Z3B NJM2114 84 Z3C NJM2114 + C8 10U EL + C108 10U EL R9 120R MF R109 120R MF R

41、8 22K MF R108 22K MF C9 100P CD C109 100P CD L1 15MH_VAR L101 15MH_VAR R6 4K7 MF R7 10K MF R106 4K7 MF R107 10K MF R5 12K MF R3 12K MF R103 12K MF R105 12K MF +C7 10U EL +C107 10U EL C6 680P PP C106 680P PP C5 680P PP C105 680P PP C4 4N7 PP C104 4N7 PP FM Audio AM Audio C1 330P PP C101 330P PP C2 22

42、0P PP C102 220P PP C3 470P PP C103 470P PP R2 82K MF R102 82K MF + C522U2 EL + C2110U EL FM R11 82K MF R12 82K MF D13 1N4148 D14 1N4148 Q8 BC547B R13 10K MF R14 4K7 MF AMUTE OFF TUNE P12V C44 47N CD MONO F1 T100MA C91 10N CD 10 12 4 5 7 230V 115V 6 T1 A52T_MAINS_TX * R91 10K MF P5V STEREO HS1 TO220H

43、S30 P12V A_LIVE A_NEUT A_SECA A_SECB A_SWA A_SWB A_GND A_P12V A_VBLA_P5VA_P5V6 A_MUTE A_AUDGND A_LEFT A_RIGHT C D E Q18 BC547B R26 4K7 MF R27 4K7 MF P5V D15 1N4148 D16 1N4148 Q5 BC547B R50 10K MF + C37 100U EL R35 100K MF R36 4K7 MF P5V6 Power Mute D9 1N4148 A_MONO R49 22K MF R104 NOT FITTED R4 NOT

44、FITTED TP1 TP2TP3TP4TP5 EMC 1 N F SK4A PHONO4 4 N F SK4B PHONO4 F2 T160MA115V A_230V A_115V 50us75us 7 8 9 SW1C 10 11 12 SW1D 1 2 3 SW1A 4 5 6 SW1B R32 10K MF R48 10K MF D18 UF4003 D19 UF4003 D20 UF4003 D21 UF4003 +C32 1U0 EL C40 10N CD D12 1N4148 PICMUTE A_PMUTE A_STEREO A_FM ! ! ! Not connected HS

45、2A TO220HS30REG Vin I GND G Vout O Z47812 R34 47K MF RV1 470K PSET C57 100N PE 12 34 56 SK8DIL6 VPLG JP3JUMPER JP4JUMPER De-emphasis selection. Link 1&3 and 2&4 for 50us. Link 3&5 and 4&6 for 75us. 1 2 34 1 T2 CM_CHOKE pin14 pin8 pin1 pin2 + C11 10U EL R86 4K7 MF INITIAL RELEASE00-1044MGM31/7/00 1.2

46、00_1078CL12/09/00R93 WAS 220R NOW 1K0 12345678 A B C D 87654321 D C B A ISSUE DRAWING NO. DRAWING TITLE Drawn by: DATE Filename ECO No.DESCRIPTION OF CHANGE G:DATAECOECO AGENDA00_1078 L892 T51 TUNERL892_1L892_1.ddb - L892C4_1_2.SCH A & R Cambridge Ltd. Pembroke Avenue Denny Industrial Centre Waterbe

47、ach Cambridge CB5 9PB T51 Tuner Circuit Diagram L892CT CAH/SJB 12-Sep-2000 INITIALS Date Printed 44Sheetof XIN 1 TEST 1 2 REMO 3 STEREO 4 K5 5 K4 6 VOL 7 FM 8 MW 9 LW 10 SW1/VU 11 SW2/VD 12 MO/ST 13 MUTE 14 CE 15 DO 16 CLK 17 IFCNT 18 NARROW 19 PWROUT 20 AMUTE 21 STB 22 T7 23 T6 24 T5 25 T4 26 T3 27

48、 T2 28 T1 29 T0 30 Vdd 31 K3 32 K2 33 K1 34 K0 35 S28 36 S27 37 S26 38 S25 39 S24 40 S23 41 S22 42 S21 43 S20 44 S19 45 S18 46 S17 47 S16 48 S15 49 S14 50 S13 51 S12 52 S11 53 S10 54 S9 55 S8 56 S7 57 S6 58 S5 59 S4 60 S3 61 S2 62 S1 63 COM2 64 65 INT 66 HOLD 67 RES 68 SD 69 HCTR 70 LCTR 71 SNS 72 V

49、dd 73 FMIN 74 AMIN 75 Vss 76 EO1 77 EO2 78 TEST 2 79 XOUT 80 COM1 Z10 LC7230 X1 4.500MHZ C80 33P CD C82 33P CD AMIN FMVt AMVt HCTR LCTR D1 1N4148 D2 1N4148 D3 1N4148 D4 1N4148 D5 1N4148 D6 1N4148 D7 1N4148 D8 1N4148 D23 1N4148 D10 1N4148 D11 1N4148 AMAN STEREO FM LW MONO IFCNT AMUTE SD C1210N CD R65 10K MF R62 10K MF Default = Low ON TUNE D17 1N4003F + C78 100U EL C13 10N CD P5V P5V6 + C84 0F1 EL A K0 A_K1 A_K2 A_K3 A_T0 A_T1 A_T2 A_T3 A_T4 A T5 A_S20 A_S21 A_S22 A_S23 A_S24 A_S25 A_S26 A_S2