Arcam-P1-pwr-sm维修电路原理图.pdf

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1、ServiceManualP1 Ampli erIssue 1.0ARCAMARCAMBringing music & movies to lifeBringing music & movies to lifeRadioFans.CN 收音机爱 好者资料库 Contents List ! Circuit description ! Circuit diagrams o L929AY switch PCB o L962AY amplifier main PCB ! Transformers o L929TX 115/230VAC toroidal o L927TX 100VAC toroidal

2、 o L907TX 100VAC frame ! Exploded view diagram ! Mechanical & packing parts list ! Circuit board silk screen & parts list o L929AY switch PCB o L962AY amplifier main PCB RadioFans.CN 收音机爱 好者资料库Fmj P1 Amplifier circuit description by A.Moore Product description The P1 has been has been designed to pr

3、ovide unsurpassed sound quality, the main design features are as follows. o Gain switchable between Arcam gain and THX gain (29dB closed loop) a 0dB signal equates to 100 watts into 8 ohms. o Input switchable between unbalance phono and balance XLR. o The amp is capable of producing 180 watts of sin

4、usoidal output into an 8 ohm load and greater than 300 watts into a 3.2 ohm load (subject to thermal dissipation limits). o Relay coupled for silent on/off operation. o Opto-isolated fault and control lines to the control PCB. o DC coupled signal path with integrating servo to remove residual DC err

5、ors. o Instantaneous safe operating area protection. o Exceptionally low harmonic and intermodulatiion distortion. o Flat frequency response. o Fast and asymmetric slew rate. o High damping factor o Unconditionally stable into loads of upto +/- 90-degree phase. Power supply/Control description The m

6、ains input is applied via SKT1. Y capacitors C1 and C2 and X capacitor, C5 provide filtering and EMC suppression R2 provides a discharge path for the capacitors. SW1 allows the selection of the mains voltage that the unit will operate from, the main standby transformer TX1 and the main transformer T

7、X2 have duel primary windings, these windings are connected in parallel for 115v operation and in series for 230v operation. TX1 is powered at all times when a mains voltage is applied to the mains input socket the secondary of this transformer is fused by via FS3 and rectified by diode bridge DBR1

8、and regulated to 5V by low dropout regulator at location REG2 to provide a constant +5v(D) supply for the micro. Please note: the digital supply ground is connected to the chassis ground via a 100-ohm resistor. Relay RLY1 provides a means of powering the main transformer for normal operation (as app

9、osed to standby operation where only TX1 is powered) this relay is under the control of the Micro IC1 and SW3 on the control board the relay contacts of RLY1 are suppressed by C3 and C4 these prevent sparking and increase the relay life span. The circuitry around TR10 functions as a mains present de

10、tection circuit A.C is feed into this circuit before the Bridge network at location DBR1 when mains is present the circuit drives HI via opto-coupler TR11. Relay 2 is the speaker output control relay this is used to prevent clicks and pops at power/power down and to disconnect the speaker output und

11、er a fault condition, this relay is controlled by the Micro at location IC1 as the P1 has no manual speaker switching capabilities the micro will automatically initialise the speaker relay 3 seconds after power up, the control line SPKR1 on pin 5 of CON 4 switches high to switch the relay ON via TR9

12、. The P1 has two trigger inputs these are applied by SKT2 and are wire OR-ed by D5 and D6. The single trigger signal is clamped to 4v7 by DZ1 and fed to the control card by CON4. Applying a 12v trigger signal to either (or both) trigger inputs on the SKT2 instructs the microcontroller to enable or d

13、isable the power amplifier. The trigger will be seen as a HI line on Pin 11 of CON 4. The P1 also provides two 2 triggered outputs. These are current limited 12v D.C levels, which are used to provide trigger signals to other units within the customers installation. The 12v output is present when tra

14、nsformer TX2 is live i.e. when the unit is not in standby. TX2 has a Low voltage secondary winding that supplies the trigger outputs only via bridge rectifier DBR4 this is fed into REG1 (7812) regulator, TR1 and TR2 offer a 60mA current limit for both trigger outputs and the entire circuit stage is

15、fused by FS6 (T315mA) in case of overload. The P1 utilizes a fairly unique main power amp power supply configuration these include. Fig 1. Power amp power supplies. Power supply Powers +/- 67v D.C VAS stage. +/- 58v D.C Output driver stage. The two sets of supplies are driven from their own secondar

16、y windings and bridge rectifier circuits DBR5 and DBR6 Rectify the +/- 58v rails these are smoothed by 20,000uf of capacitance per phase. DBR2 and DBR3 are supplying the +/- 70v rails these are dropped to +/- 67 by the Network of R5, R6, R7, R8 and TR3, TR4, TR5, TR6 this is not a regulated supply a

17、s the rails need to track the +/- 58v rails under mains power fluctuations. Please note: The +/- 70v rails are individually fused by 315mA(T) fuses at locations FS4 and FS5. The VAS stage is supplied by higher voltage rails than the following output driver stage, this allows the driver stage to full

18、y saturate the output driver stage without the use of a boot strap circuit. This supply is exceptionally quite and is critical to the sound quality of the P1. Amplifier Stage The XLR connector at CON100 allows balanced inputs to be applied to the amplifier and CON101 allows for the balanced signal t

19、o be daisy chained to a second P1. The signal from CON100 is driven into IC100 this is a Balanced to single ended converter it supplies a signal-ended output from a single XLR input. The IC derives it power supply rails from the +/- 67v rails these are dropped to +/- 15v by the TR100 and TR114. The

20、unbalanced inputs signal arrives at SKT100; the selection between the two input options is accomplished by SW100. The selected signal is clamped +/- 5v3 by the series Zeners at location DZ103 and DZ104 this is to prevent damage to the input of op-amp IC200, due to leaky source signal or electrostati

21、c discharges. SW101 allows for the selection of two gain settings these are 28.3 for “THX” and 37.5 for the Arcam setting. The roll off setting is 340Khz. The main power amplifier circuit is a classic current feed-back design and can be thought of as a large current feed-back op-amp the topology is

22、a refined high power output variant of the A90/P7 design. Op-amp IC101 is configured as a non-inverting amplifier with a gain of 2. Its purpose is to provide current outputs (via its own power supply pins) and a current input via its output pin, the Op-amp performs the voltage to current conversion

23、(I-V) and phase splitting necessary to drive the voltage gain stage. The current feed-back occurs because the output of IC101 drives into a 44 ohm load formed by the two 22 ohm resistors R142 and R143 down to ground, the power Cont/ supply pin currents are half wave-rectified versions of the drive c

24、urrent of the amplifier. This causes the voltage gain, which is buffered and passed on to the outputs. The feedback from pin 1 of IC101 acts to reduce the gain of the amplifier; when this current is roughly equal to the current required to drive the input signal into 44-ohms equilibrium is reached a

25、nd the closed loop gain is defined. The output stage provides the vast majority of the current required to drive the 44-ohm load. The op-amp only needs to provide a very small error current to give the required voltage magnification. Transistors TR101 and TR116 are common base amplifiers their purpo

26、se is to provide the +/- 15v rails necessary to drive the op-amp whilst allowing the power supply currents that are drawn to pass through into the Wilson current mirror stage, this is formed by PNP transistors TR102, TR104 and TR122 the NPN mirror is formed by TR115, TR117 and TR122. TR103 combines

27、the two current mirrors to provide a very high-gain current to voltage (transresistance) gain stage roughly 80dB at low frequency C114 and C132 with R149, R150 combine to give a open-loop pole at roughly 10Khz and a corresponding open-loop zero around 500Khz. This allows for good time domain perform

28、ance and clean square wave reproduction with no sign of ringing or overshoot. Diodes D100 and D101 act to limit the current through TR115 and TR112, if the input current exceeds 14mA the diodes conduct and the transresistance stage becomes a constant current source killing the open loop gain and pre

29、venting damage to the transistors. IC101 forms a D.C intergrating servo. Its purpose is to remove residual D.C errors due to slight device mismatch and component tolerances. It is configured as an inverting intergrator with a time constant of 0.5 seconds. Any D.C offset at the output of the amplifie

30、r will cause the output if the op-amp to go negative increasing the current in the negative supply pin and thus pulling the output down to ground (and vica versa). D108 protects the inverting input of the op-amp under fault condition. TR103 provides a 4.7v bias voltage to allow the following pre-dri

31、ver stage to operate in Class A. TR123 and TR125 form a Class A pre-driver emitter follower stage to boost the current gain and isolate the transresistance stage from the output transistors. TR105 and TR118 act as a 30mA current limit and prevent the destruction of TR123 and TR125 under a fault cond

32、ition. R109, R164, R110 and R165 loosely decouple the emitters of TR123 and TR125 from the output stage. TR128, TR129 and TR126, TR127 are Sanken SAP 15N and SAP 15P Bi-polar output drivers RV100 is the Bias adjust preset D104 protect the Output drivers from destruction if RV100 goes open circuit. C

33、144 to C147 provide local R.F stability and prevent oscillation. D111 and D112 are catch diodes to reduce the effects of back-EMF from the loudspeaker coils/load. R164, R183, C150 and L100 form the Zobel network, these components ensure that the amplifier sees a constant load of 4.7 ohms at high at

34、very high frequencies and improve stability reduce H.F noise. L100 and R183 decouple the load at high frequencies to ensure amplifier stability into capacitive loads. SAP 15NY SAP 15PY S-E 0.22 Ohm SAP Under output driver failure conditions the 0.22 internal emitter resistor will usually go open, th

35、e resistor should be measured between pins S and E. Protection circuit block The P1 Power amplifier incorporates 4 modes of protection these are as follows. o Instantaneous VI current limiting. o D.C offset protection. o Over-Temperature. o Insulation failure. The VI current limit circuit is built a

36、round TR106 and TR119 they sense the voltage across the 0.22-emitter resistors (hence emitter current) and the collector emitter current or device power dissipation exceeds a preset limit. The circuit is designed to allow large unrestricted currents into loads of 3 ohms and above but limit the curre

37、nt into a short circuit or very low impedance loads. C141, C142 and R162, R163 form a 2.2ms time constant, which will allow larger transients of current delivery for a few milliseconds, to ensure that the amplifier has a sufficiently large transient capability to drive “difficult” loudspeaker loads.

38、 TR106 senses positive current surges and TR119 senses negative surges these intern activate TR107 and switch the optocoupler OPTO100A this fault notification is sent to the microcontroller and the output relay is switched off to protect the amplifier/loudspeaker coils. The t s( )-10.7wiil inten (s)

39、-1237witcsT107 and TR109oan in Test Specification Frequency response. 8-ohm load Input set to 1v rms 20Hz 20kHz = +/- 0.5 dB. Distortion. THD+N 0dBR 4-ohm load. Input set to 1v rms. 20Hz 20Khz = 0.02% Maximum output into an 8-ohm load. Input level set to 1.34 rms 1Khz = 180 watts distortion should b

40、e below 0.05% THD+N Bias setting notes The bias of the P1 is set using an Audio precision audio analysis package and we calibrate the power stage for minimum THD the bench set up procedure follows. o Set the input signal to 150mv rms, frequency to 10kHz. Induce a 4-ohm load at the speaker output. o

41、Rotate preset RV100 clockwise and observe that the THD falls. Continue to rotate the preset until the THD falls to a minimum level and just starts to clime again. o Switch input signal off and allow the amplifier the Quiesce +30secs o Measure the bias level at test point Con 103 (Bias read) and conf

42、irm the reading is below the absolute max of 35mV. Major component identification. FMMT 497/597 BC849/BC859 1=Base 2=Emitte -23.2( -23.2()-11.6( -11.6( -11.6T)210.2L)-8.6O)2.5(73)11.82e ( )?T?ET?q?5990265 0 0521.32 38042 341.32 cm?/I42 Do?Q?BT?11.2584 0 0 11.28 439.56 341.32 Tm?0 Tc?( )Tj?15.5824 -0

43、.9149 TD?( )Tj?0 -1.1489 TD?( )Tj09 -1.1596 TD?( )Tj?0 -1.1489 TD?( )Tj09 -100759 TD?-0.0074 Tc?( ( )-10.7( )?T?/TT2 1 Tf?10.3576 0 0 10.3772 8)8. ?332886 Tm?0.0174 Tc?SSs2143 ISSUEDRAWING NO.DRAWING TITLEDATEFilename:ECO No.DESCRIPTION OF CHANGEL929CT_1.0.schP35 / P1 Switch PCBContact Engineer:L929

44、CT13-May-2003INITIALSPrinted:11SheetofNotes:Contact Tel:(01223) 203243Kevin LambA & R Cambridge Ltd.Pembroke AvenueCambridge CB5 9PBWaterbeachARCAMA3STANDBYSPKR1 ONSPKR2 ONTHERMPROT 1VIPROT 1DCPROT 1AC PRESENTTRIGGERREMOTE+5V_D0V_D0V_D0V_DDCPROTVIPROTSP2 LEDPWR GRNPWR REDSP2 SWSP1 SWSPKR2 ONSPKR1 ON

45、STANDBYPWR SWREMOTETRIGGERAC PRESENTSP1 LEDTHERMPROTTHERMPROT 1THERMPROT 2VIPROT 1VIPROT 2DCPROT 1DCPROT 2DCPROTVIPROTTHERMPROT0V_D+5V_DSP1 LEDSP2 LEDPWR REDPWR GRNPWR SWSP1 SWSP2 SW+5V_D0V_D+5V_DSPKR1 ONSPKR2 ONTHERMPROT 2VIPROT 2DCPROT 20V_D+5V_D0V_D+5V_D0V_D0V_D0V_D0V_DSPKR1 ONSPKR2 ONSTANDBYJR1/

46、11/01LEDS TO 5MM AND MAINS SWITCHB.0WAF2/01/02HOLTEK, Z1 UPDATEDB.103_E0011234567891011121314CON1MOLEX5229-NAPB1234567891011121314CON2MOLEX5229-NAPBSTANDBYAC PRESENTTRIGGERREMOTETR5BC546BTO-92TR6BC546BTO-92TR7BC546BTO-92TR1BC556BTO-92TR2BC556BTO-92TR4BC556BTO-92TR3BC556BTO-92R110K0W25MFR210K0W25MFR3

47、10K0W25MFR410K0W25MFR510K0W25MFR610K0W25MFR710K0W25MFR810K0W25MFR12560R0W25MFR13560R0W25MFR14330R0W25MFR15180R0W25MFR19470R0W25MFR20470R0W25MFR21470R0W25MFR1710K0W25MFR1810K0W25MFR910K0W25MFR1010K0W25MFR1110K0W25MFR2210K0W25MFR2310K0W25MFR2410K0W25MFC14100UF25VYKC6100UF25VYKC7100UF25VYKC8100UF25VYKC

48、510UF50VYKD11N4148DO-35D21N4148DO-35R16100K0W25MF123IC2A74HC32NDIP-14456IC2B74HC32NDIP-149108IC2C74HC32NDIP-14121311IC2D74HC32NDIP-14VCC14GND7IC2E74HC32NDIP-14C9100N50VX7RC10100N50VX7RC11100N50VX7RC12100N50VX7RC13100N50VX7RC2100N50VX7RC3100N50VX7RC4100N50VX7R1FIX1Dia 3.5mm1FIX2Dia 3.5mm1FIX3Dia 3.5m

49、m1FIX4Dia 3.5mm1FIX5Dia 3.5mmC1100N50VX7R123X14.00MHzSIL-3LED15mmGRNLED 5mmLED25mmGRNLED 5mm12SW1SKHVPB000A12SW2SKHVPB000A12SW3SKHVPB000A0V_DLK10R00W25MFPB51PB42PA33PA24PA15PA06PB37PB28PB19PB010VSS11(TMR)/INT12PC013PC114PC215PC316PC417PC518RES19VDD20OSC121OSC222PA723PA624PA525PA426PB727PB628IC1HT48R

50、30A-1L019SWDIP-28LINK LK1 IS USEDTO CONFIGURE PCBFOR USE IN P35 OR P1FOR P35 - LEAVE LK1 INTACTFOR P1 - CUT LINKLK20R00W25MF0V_DKAL8/05/03Redrawn, LED1, 2 swapped, Connectors rewired, LK1, 2 added1.003_E125ITEM11Blank PCB P35/P1 FMJ Amp Microcontroller BoardL929PBTOOL1TOOL2SPARE1SPARE2SPARE1SPARE2SP