Ecler-PAM4100-pwr-sm维修电路原理图.pdf
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1、 SERVICE MANUAL SIGNALPROTECTTHERMALTHERMALBRIDGEDPROTECT61001243598SIGNALCLIP71203459108CLIP67ONOFFSWITCHING POWER MOSFET AMPLIFIERCHANNEL ICHANNEL IITHERMALPROTECTSIGNALPROTECTBRIDGED1001298SIGNALCLIP1201098CLIPTHERMAL6435735467ONOFFSWITCHING POWER MOSFET AMPLIFIERCHANNEL ICHANNEL IIRadioFans.CN 收
2、音机爱 好者资料库SERVICE MANUAL PAM6100 / 4100 INDEX PAM6100 - BLOCK DIAGRAM - FUNCTIONING DESCRIPTION SCHEMATICS Inputs circuit Power Amplifier circuit Soft-Start Power Supply circuit Potentiometers and leds circuit Capacitors circuit Speak on circuit - COMPONENTS LOCATION SCHEMA AND PARTS LIST Inputs circ
3、uit Power Amplifier circuit Soft-Start Power Supply circuit Potentiometers and leds circuit Capacitors circuit Speak on circuit - TESTING AND QUALITY CONTROL - TECHNICAL CHARACTERISTICS - WIRING DIAGRAM - MECHANICAL DIAGRAM - PACKING DIAGRAM PAM4100 - COMPONENTS LOCATION SCHEMA AND PARTS LIST Power
4、Amplifier circuit - MECHANICAL DIAGRAM RadioFans.CN 收音机爱 好者资料库SHUTDOWNSHUTDOWNINPUT CIRCUITS.P.OFFCH 2S.P.20HzHIGH PASS FILTEROFF40Hz30Hz20Hz30Hz40HzVCA-VrefVOLUMEAC DETECTBRIGMODULESOPTIONALBRIGPROTECTOUTPUTCONTROLANTICLIPAND TIMERPROTECTIONRELAYOUTPUTCLIPHIGH PASS FILTERCH 1THERMAL PROCESSORTHERMA
5、L PROCESSORTHERMAL PROTECT FAN CONTROLTHERMALOPTIONALSTEREOMODULESPROBETRANSFORMERPROBE MODULETHERMAL-VrefVCATHERMALADJ 0dBCONTROLVOLUMEFANCROWBARPOWER MODUL CIRCUITOUT 2POWER MODUL CIRCUITLEVELCONVERTERDRIVERMOSFET NOVERLOADLOW SIDE-VccLEVELCONVERTERFEEDBACKDRIVERMOSFET NMIRRORWILSONCURRENTZOBELDC
6、PROTECTHIGH SIDEOVERLOADOUT 1+Vcc+Vcc+15Vauthor:Queraltdate:010418project:EP04-99product:PAM4/6100approved:num:52.0010version:01.00title:FUNCTIONING DESCRIPTIONECLEREPO4-99 Power Module. Functioning description.Due to the high power level required on the output load, the amplifier final stagesstruct
7、ure differs from the design used untill now. This is due to the breakdown voltagelimit on P-channel MosFETs, wich is 200V. This final stage is formed by severalshunted MosFETs, where those of the positive branch are common-drain configured,and the negative branch are mounted in common-source configu
8、ration.The systems controlling device is a NE5534-type operational amplifier, wich isinternally compensated in order to obtain gain levels equal or higher than three. Theamplifiers feedback is given by a resistor and a capacitor associated to the operationalamplifiers non inverting input.Transistors
9、 BF587 and BF588 are common-base configured, forming a current supplystructure. This specific transistor type is used because of the higher Vce voltage levelrequired by this design. They perform simultaneously two functions: they polarize theMosFETs gate-source junctions, keeping them on the conduct
10、ing edge, and theytranfer the OpAmps output voltage variations referred to signal ground.The signal variations normally reflected by Q107 and referred to the positive powersupply, are now needed to be floating variations, and referred to the outputs. Thisfunction is done by Q109-110 (BF588), wich ar
11、e mounted formig a Wilson-type mirrorcurrent supply. This mirror current supply transfers all of the current variations detectedwhile descending through Q109s collector, to similar variations on Q110s collectoralso downward current. Resistors R167 and R174 are used to balance the currentmirror, in o
12、rder to avoid the use of transistors with forcibly the same beta value. C138and C141 suppress their resistance when high frequency signal is processed. DiodesD126 and D127 avoid the transistors to get saturated, and R171 eliminates the loadson BF588s bases (Baker Circuit).The system requires about 1
13、2Vdc additional voltage upon the usual Vcc level, thisallows a correct saturation and a symetric clipping at the higher MosFETs.The correct polarization current value is adjusted by a 4K7 potentiometer connected tothe BF transistors emitter. This adds an additional current to the current source outp
14、uton th BF transistors loading resistors. In order to maintain the appropiate stand-by current level against varying temperatureconditions, BD437-type transistors are used. As they have a particular temperature-depending base-emitter voltage curve, this voltage is used to keep a correct voltagerefer
15、ence for the current supply. As the temperature rises, the reference voltage leveldecreases, the gate-source voltage also decreases and, finally, the bias current alsodecreases. 52-0010-0100 EP04-99 Angls.xls 1 of 3 Transistors Q111 and Q112, and their corresponding twins at the lower branch, forma
16、current-buffering circuit wich allows a fast charge and discharge of the powerMosFETs gates.The Zobel circuit, a resistance-capacitance-inductance formed network associated tothe amplifiers ouput, tries to keep the amplifiers output load impedance constant nomatter wich load value is conected to the
17、 output, or wich frequency is processed, inorder to avoid phase shifts on the feedback signal.To avoid the presence of DC voltage on the output, a diac-triac based system is used,wich shorts the output to signal ground in case the DC level reaches the diacstriggering value. To avoid this to happen w
18、hen processing correct signal (sinewaveform, music.), the diac obtains its reference level from a filtering network formedby a 100K resistor and a 1mF capacitor.The protections circuitry overhauls the MosFETs power consumption. Basically, thiscircuitry consists of two important sections: MosFETs Id
19、current monitoring, andMosFETs Vds value detection.When the MosFETs Id level rises above a certain level, transistor Q119 (controllingtransistor) conducts and decreases the BF transistors loading resistance, thus reducingalso their gate-source voltage and, finally, lowering the Id current value. Thi
20、s system ishelped by a delayed performance, due to the associated circuitry to Q145 and C174.This capacitor starts to charge when a current level above the allowed value isdetected, and the protection starts. The greater is the capacitors charge level, thehigher is also the voltage applied to Q119 c
21、ontrolling transistors base, increasing itsconduction and, consequently, reducing the gate-source voltage and thus the Id currentvalue. This system uses a feedback network. The delay used is necessary to avoidclipping the processed signals dynamic range, wich should result in the typical clippingnoi
22、se. In the negative branch, the protection circuitry is associated to control transistorQ120.In case the overcurrent is not ocassional, and persists, after a period of time between4 and 10 seconds (determined by R142 and C124), the system switches back to Stand-by mode, due to a system-reset. This i
23、s done by an optocoupler (IC113) associated tothe negative branch protection circuitry. When protections get activated, IC113gradually charges C124 untill a 40106-type Schmidt trigger gate switches over . If theproblem persists, this cycle is repeated. STANDBY CIRCUITRY. This circuit maintains the O
24、utput shutdown relay closed for about 10 seconds, andthus annulates any current through the MosFETs during this period, just untill thewhole systems power supply voltage reaches its stable level. By this system, we avoidto hear through the loudspeakers any possible annoying noise proceeding from the
25、systems start-up.52-0010-0100 EP04-99 Angls.xls 2 of 3ThisdelaytimeisachievedbyusingaRCcell,whereR135=287KandC119=47mF/50V. As this cell charges, its voltage increases untill reaching the 40106-type Schmidt trigger (IC108) switching value; at this point, the relay opens and theamplifier starts to fu
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