kenwood–kd-4100–维修电器原理图手册-supplement–ID15905

KENWOODHI/FI STEREOCOMPONENTSSERVICE MANUALK0-4100SUPPLEMENTThis manual documents mechanical operation ofThe record size selection circuit includes a circuit which setsthe KD-4100.the record size to 30cm when power is turned ON.Whenpower is turned ON,a charging current flows into C19 andRecord Size Selection CircuitB is applied to Pin 6 of IC9,then Pin 9 of IC12 is set toMomentary switches which make contact only while they are'H'',so that Q2 is turned ON.Q2 drives the 30cm sizepressed are used as the record size selection switches in theselection LED (in the POSITION holder,which has 3 LEDs,KD-4100.Therefore,the input signal must be held after theone for each record size,to let the arm detect the lead-in posi-switch has been released.Further,a circuit which inhibits thetion.and the LED built in the 30cm size selection buttonrecord size selection under certain conditions is necessary:When the 25cm size selection button is pressed,Pin 1 ofe.g.while a 30cm record is being played,25cm and 17cmIC1 1 becomes "'L''.Pin 3 of IC1 1 can be "'H''only when Pinsize selection must be inhibited.The record size selection cir-2ofIC11 is also "L“When Pin3ofIC11isH“,“H"levelcuit used in the KD-4100 satisfies the above requirements.is applied to Pin 1 of IC9,then Pin 10 of IC12 is set to "H"Its configuration is as follows.and Q1 is turned ON.Q1 drives the size selection LED and theLED built in the size selection button.For 17 cm size selec-tion,circuit operation is similar to the aboveSwitchInput enablingHold circuitIndicatorcircuitdriversnitialization circuit(30cm is always selected after power is tumed ON.IIC1 1 judges whetherinput is allowed or notOne of RS-FFs'holdsthe input signal.This LED lights whenBpower is ON.PHA-2Lights when 02 is ONR60R49NOI69w©PHA-I30.2530022no7are ON.30Lights when Q1 and Q7are ON.25257Lights when Q163ZISis ON.3SEARCHR46This LED is mounted on the top of the searcharm and lights when power is ON.REPEATR22108.9Input is allowed when this level is"L"PLAY/CUT2and inhibited when it is"H'.This level becomes“Hwhen the PLAY button is pressed.so 07 is tum.*RS-FF stands for RS typeflip-floped ON.1