HarmanKardon-CA240-pwr-维修说明书手册含电器原理图

CA240SPECIFICATIONSPower Output,RMS40 watts per channel intoPower SupplyDC +13.8V (11~16V usable),40hm5.2020.000Hznegative ground50 watts per channel intoTypical Input Current Requirements20hms,2020,000HzAt Idle:1.9A100 watts bridged mono intoFull Power Music Signal:4A(4 Ohms/ch.)40hm5,2020.000Hz:6A(2Ohms/ch.】HCC (High Instantaneous:t25AFull Power Sine Wave 12A (4 Ohms/ch.)Current Capability)18A (2 Ohms/ch.)THD (4 Ohms/2 Ohms):No more than 0.1%/0.2%Dimensions (W x Hx D)12-1/4"x2-11/16"x8"Negative Feedback:25dB(310×68×203mm)Power Bandwidth:10Hzto100.000HzWeight5 Ibs.12 oz.(2.6 kg)Frequency Response:10Hzto100,000Hz+0,-3dBSignal-to-Noise Ratio:80dBSpecifications and components subject to change without notice.Input Sensitivity0.25~3V AdjustableOverall performance will be maintained or improved.Active Crossover CharacteristicsHigh Pass200Hz,12dB/OctaveLow Pass200Hz,12dB/OctaveDISASSEMBLY PROCEDURES (REFER TO PAGES 4 AND 8)1 CABINET BOTTOM (143)REMOVAL2.Remove the Insulator (159).Remove 6 screws and remove the Cabinet Bottom3.Remove 11 screws and remove the Frame (141)(143).with Bracket (162).4.Remove 10 screws and remove the Main P.C.2 MAIN (PCB-1)AND FILTER (PCB-2)P.C.BOARDSBoard (PCB-1)with Filter P.C.Board (PCB-2).IfREMOVALnecessary,unsolder the lead wires.1.Remove the Cabinet Bottom (143).(Refer to step①ALIGNMENT PROCEDURES (REFER TO PAGES 7 AND 8)Conditions:Connect a 13.8V power supply to the 12V BATTERYAfter the power on,wait for 5 minutes beforePOWER IN terminal.measuring to be sure of the most stable operation.IDLING CURRENT ADJUSTMENTStepConnection EquipmentsAdjustmentFor1Connect the DC voltmeter to TP1 (+and TP2 (-)VR40133mV2Connect the DC voltmeter to TP3 (+and TP4 (-)VR40233mVAfter the adjustment is complete,let the unit settle down for 10 minutes,than double-check that the idling current is setproperly.CIRCUIT DESCRIPTIONGeneral Description of the CA240 Power Supplyprimary windings and one-half of the T1 primaryThe power supply voltages for the Power Amplifier arewinding thereby generating a voltage in the T1 feedbackgenerated by means of a switching power supply.Thewinding.switching power supply consists of transformer L2,This voltage causes a current to flow through the L2transistors Q5 through Q9,transformer T1 and bridgesecondary winding via R17 and the center tap of L2.rectifiers D12 through D16.This switching power supplyThis current also flows through the base emittor junc-is connected to associated circuits which control thetions of Q5 and Q6,D8,D9 and Q9.This current keepsinitial turn on delay,thermal protection and loadQ5 and Q6 on.protection.The purpose of D8,D9 and Q9 is to develop a negativebias voltage which speeds up the switching time of Q5Circuit Description of Switching Power Supplythrough Q8.The voltage across the L2 secondaryUnder normal operating conditions the collector of Q2 iswinding continues to rise until core L2 saturates.At the+8.1 volts and Q3 and Q4 are turned off.moment L2 saturates the voltage generated by