PL-3clcIX
Contents
1. Fig 7 3 d 7 3 OPERATION OF THE PD1003 1 OSCILLATOR STAGE 1 Once the power supply is turned on the quartz crystal oscillator generates a 6144kHz signal 2 The frequency of this signal is reduced to 1 5kHz 1 4096 division by frequency divider I Part of the resultant signal is passed via the X tal RC switching circuit and applied to frequency divider II The other part of the signal is applied to frequency divider selector II 3 The 1 5kHz signal applied to frequency divider II is further divided into a 750Hz signal and applied to frequency divider selector I where the signals are converted into sampling pulses for phase comparison purposes in PA2004 33rpm 27 78Hz 45rpm 37 5Hz In both cases the pulse width is 0 667ms 4 Frequency divider selector II converts signals from frequency divider I into pulse signals for the stroboscope lamp drive circuit 33rpm 55 5 2 45rpm X 75 0Hz In both cases the pulse width is again 0 667 ms NOTE This IC PD1003 is not employed in the motor of the PL 200 and PL 225 models 16 7 4 OPERATION OF THE 2004 IC COMPARATOR CONTROL Signals from the frequency generator in the motor rotation ass y are changed into 50 duty square wave signals by the waveform rectifier The frequencies at this stage are thus 33rpm 55 55 2 45rpm 75Hz Part of the output is divided by in the FF circuit and subsequently applied to the FV converter circuit along with2. Reverse Rotation Prevention 1 This motor operates indiscriminately in regard to the direction of rotation If the platter is turned slowly in the reverse direction by hand a forward torque will be applied until the platter Stops reverses its rotation and reaches rated speed in the proper direction 2 If however the rotational speed in the reverse direction is in excess of 83 or 45 rpm the Forward Reverse Command Block may mis read this as simply excessive speed overrun and apply a reverse torque until rated speed is attained 3 This reverse torque will further accelerate the turntable rotation in the reverse direction This is known as reverse run away 4 To prevent this from happening a Reverse Rotation Prevention circuit has been included 5 This Reverse Rotation Prevention circuit con sists of two flip flops and AND gates See Fig 7 4 6 The input for this circuit is derived from the Hall element position detection signals processed in the Reverse Rotation Prevention circuit 7 As long as the platter is rotating in the proper direction this pulse enters in the order B A C and no reverse command is generated 8 If however the platter rotates in the reverse direction the pulse order becomes A B C and a corrective command is given to the For ward Reverse Command Circuit AND Output Forced Forward Rotation at 0 output Fig 7 4 AND
3. For the automatic play of 25cm 10 inch LP records 12730 For the automatic play of 30cm 12 inch LP records G STROBE LIGHT This light comes on when the tonearm moves away from the arm rest toward the platter It irradiates the strobo scope around the outside of the platter 5 SPEED SELECTOR BUTTON AS uas When this button is depressed the platter will rotate at 45rpm Depress for playing 45rpm records singles or EP s 99 66 a4 When this button is set to the release position the platter will rotate at 33 1 3rpm Release for playing 33 1 3rpm records like LP s TONEARM This tonearm is designed to apply the correct tracking force to the cartridge and to keep this force at the precise level for faithful tracking of the record grooves It also has the job of switching the power on to the turntable When the tonearm is moved from the arm rest to the platter the power comes on the strobe lamp lights up and the platter rotates When the tonearm is returned to the arm rest the power to the turntable is cut off the strobe light goes off and the platter stops rotating ARM ELEVATION LEVER UP CE When this lever is set to this position the tonearm will rise Set it to UP before re cord play and when you want to stop re cord play while a track is being played or when you want to change over to a differ ent track DOWN Y When the lever is set to this position the tonearm will be lower
4. lout 2out 0 Forward rotation rotation Reverse Truth table Comparator Control and Forward Reverse Com mand Circuit 1 Two inputs are supplied to the Control Com parator a 4V reference voltage from the volt age stabilizer and b the output from the active filters which serves as the detection signal 2 If the turntable rotates faster than rated speed the detection signal is higher than the 4V reference 3 When this happens the Comparator Control sends a command to the Forward Reverse Com mand Circuit telling it to apply a reverse torque to the motor to slow it down 4 Conversely if turntable rotation is below rated speed the detection signal voltage will be below the 4V reference 5 In this case the Comparator Control indicates to the Forward Reverse Command Circuit that forward torque must be applied to the motor to accelerate it t V Area of 5 of reverse c ey torque 8 i 5 4 Operating point at zero load 0 Input voltage differential between V18 Voltage at pin 18 pins 18 and 19 V19 Voltage at pin 19 Fig 7 5 17 l 2 3 Ta Drive Circuit The signals emploved in the switching of Q2 Q7 in Fig 7 6 are generated by 3 Hall elements and applied to terminals a b and c via the position signal formation circuit The phase of these step wavefo
5. Release for playing 33 1 3rpm records like LP s 5 DISASSEMBLY 5 1 PANEL AND BASE PLATE 1 Undo the 4 screws securing the insulator legs 2 Move the tonearm across to the center and raise the panel a little 3 Disconnect the D D motor and circuit board connectors 2 pin and 5 pin S Power supply 5 pin connector ass y 2 pin gt AN lt sae sw AS Insulator case Float spring black E ie Float spring Damper rubber Float spring amp ed l e amp L Float spring amp Fig 5 1 5 2 D D MOTOR AND TONEARM 1 After removing the panel undo the 3 screws B securing the motor 2 Undo the 4 screws amp securing the arm base Base plate Tq Fig 5 2 6 PANEL AND BASE PLATE ASSEMBLY 6 1 PL 200 PL 300 L 2 3 Rotate the motor clockwise by hand to reset the motor mechanism Move the tonearm across to the center after removing the main weight and headshell With the base plate half covered by the panel connect the microswitch 2 pin connector to the power supply ass y and connect the power supply ass y 7 pin connector to the motor ass y See Fig 1 Clamp all lead wires with cord clamps and check that there are no other obstacles to normal operation of the mechanical parts Shift springs A and B across to the left as shown in
6. Fig 3 spring A being positioned to the left of spring B When the cut button is pressed spring A will snap back to the right hand side of spring B Then cover the base plate completely by the panel move the tonearm across to the arm rest and clamp it into position Screw in the insulators insulator case float spring and damper rubber to secure the panel to the base plate The front left hand float spring differs from the other 3 Check that they are all correctly mounted as shown in Fig 1 Spring A Fig 6 1 11 6 2 PL 255 PL 400 1 10 12 Attach the insulators Rotate the motor clockwise by hand and check that the main mechanism has been reset to the stationary state Shift the tonearm across towards the center and remove the main weight and headshell Attach spring A to the panel rib Set the size selector to the 30cm position and attach spring B to the panel boss Connect the 2 p connector from the micro switch to the power supply assembly and the 7 p connector from the power supply assembly to the motor assembly Note that all lead wires should be carefully clamped into position at this time in order to avoid loose wires being damaged by mechanical operation Lay the panel on the under base and return the tonearm to the arm rest and clamp it into position case float spring damper rubber and secure the panel to the under base Note that the
7. KNOB Turn this knob when finely adjusting the speed of the platter The speed of platter will increase when the knob is turned clockwise in the direction of 4 it will de crease when turned counterclockwise in the direction of Connect the ground lead with the Y shaped connector at the end to the ground terminal Insert the power plug into the convenience AC outlet of the amplifier or a wall outlet STEREO AMPLIFIER Phono input jacks AC outlet Power cord Ground terminal Dust cover Anti skate knob G CUT BUTTON If this button is depressed while the record is playing the tonearm automatically returns to the arm rest and the power to the turntable is cut off ARM ELEVATION LEVER UP Y When this lever is set to this position the tonearm will rise Set it to UP before record play and when you want to stop record play while a track is being played or when you want to change over to a different track DOWN When the lever is set to this position the tonearm will be lowered If it is set to DOWN for record play the tonearm will be lowered onto the surface of the record and play will begin 2 PL 255 PANEL FACILITIES D START CUT BUTTON When this button is depressed the power is turned on to the turntable the strobe light comes on and the platter starts to rotate With the RECORD SIZE SELECTOR set at one of the positions 30 25
8. or 17 the tonearm moves automatically to the record disc as the platter starts rotating thus starting record play If this button is depressed while the record is playing the tonearm automatically returns to the arm rest and the power to the turntable is cut off 2 REPEAT BUTTON Push this button when you want to listen to the same re cord again Press the button once more to release NOTE All you have to do for repeat play is to press the REPEAT button There is no need to push the START CUT button again 8 RECORD SIZE SELECTOR This selector selects the size of the record for automatic play 7 17 For the automatic play of 17cm 7 inch LP and EP records 10 25 For the automatic play of 25cm 10 inch LP records 12 30 For the automatic play of 30cm 12 inch LP records 4 STROBE LIGHT SPEED CHECKING WINDOW This light comes on when the tonearm moves away from the arm rest toward the platter It irradiates the strobo scope around the outside of the platter 5 SPEED ADJUSTMENT KNOB Turn this knob when delicately adjusting the speed of the platter The speed of platter will increase when the knob is turned clockwise in the direction of it will de crease when turned counterclockwise in the direction of 40 6 SPEED SELECTOR BUTTON 45 When this button is depressed the platter will rotate at 45rpm Depress for playing 45rpm records singles or EP s SO ess When this but
9. the tonearm back to the arm rest At this stage plate B commences to return towards the center shaft guided by the groove in gear A When the edge of plate B separates from lever C the arm elevation is lowered to drop the tone arm back into the arm rest And at the same time that the tonearm is re turned to the arm rest pin A returns lever A back to the stationary state Plate B continues to move towards the center shaft and pushes against pin C on lever B Lever B thus switches the microswitch off power off and is then locked by lever A thereby bringing a complete operation cycle to an end For details on the operational principles in volved in the auto return detector mechanism refer to the PL 516 Service Manual ART 279 Gear B Gear A Fig 8 4 Fig 8 5 8 2 PL 400 MECHANICAL OPERATION LEAD IN Fig 8 6 shows the PL 400 in the stationary state with the motor stopped and the tonearm upon the arm rest 1 When the START STOP button is pressed lever D will be shifted towards the left by spring B of lever F Fig 8 6 2 Pin A located above lever D then presses against plate C thereby unlocking plate C from lever C And once lever C is separated from the micro switch the power for the motor will be turned on Fig 8 7 3 The plate C plate spring will also press against lever A thereby repelling the cam A detector assembly Figs 8 7 8 4 Once th
10. the other part of the output formed in step 1 above thereby forming the FV converter gate pulse signals The output from the FV converter is applied to buffer amplifiers I and II The buffer amplifier I output is compared with the reference voltage in buffer amplifier III and then applied to the output compose circuit Phase comparison of the sampling pulses from the PD1003 IC with the FV converter output occurs in buffer amplifier II with the resultant output being applied to buffer amplifier IV The output from buffer amplifier IV is also applied to the output compose circuit This output compose circuit consists of a low pass filter cut off frequency 23Hz cut off slope 6dB oct which serves to eliminate the carrier component in the output of buffer amplifier II phase comparison This final output signal is then passed onto the comparator control stage of the PA2005 IC for comparison with the reference voltage 7 5 OPERATION OF THE PA2005 IC DRIVE CONTROL Stroboscope Pulse Circuit 1 The platter has only a single row of stroboscopic markings Switchover for 45 and 33 rpm is ef fected by changing the frequency of the pulse to the stroboscopic lamp 2 From the Frequency Divider Selector I a fre quency of either 75Hz for 45 rpm representing 1 80 of 6000Hz or 55 5Hz for 33 rpm repre senting 1 108 is obtained and supplied to the transistor that drives the stroboscopic lamp
11. LATTER When the tonearm is moved and power is supplied to the turntable the platter will start rotating at the set rotation speed The rubber platter mat stabilizes the records and also absorbs external vibration 12 DUST COVER Keep this closed unless operating the controls or tonearm or changing over records This serves to keep dust from adhering to the records during record play When fully opened and pulled straight up this dust cover can be re moved from the cabinet DOWN Y 3 PL 400 PANEL FACILITIES D START CUT BUTTON When this button is depressed the power is turned on to the turntable the strobe light comes on and the platter starts to rotate With the RECORD SIZE SELECTOR set at one of the positions 30 25 or 17 the tonearm moves automatically to the record disc as the platter starts rotating thus starting record play If this button is depressed while the record is playing the tonearm automatically returns to the arm rest and the power to the turntable is cut off 2 REPEAT BUTTON Push this button when you want to listen to the same re cord again Press the button once more to release NOTE All you have to dofor repeat play is to press the REPEAT button There is no need to push the START CUT button again RECORD SIZE SELECTOR This selector selects the size of the record for automatic play 7717 For the automatic play of 17cm 7 LP and EP records 10 25
12. LS ad NU Q PIONEER RECEIVED may 11 1981 antla l e This service manual describes the mechanical operations and adjustments and the D D motor emploved in the following models STEREO TURNTABLE L eGoo PL 200X L 2599 L 300 PL 300X L 400 PL 400X PIONEER ELECTRONIC CORPORATION 4 1 Meguro 1 Chome Meguro ku Tokyo 153 Japan U S PIONEER ELECTRONICS CORPORATION 85 Oxford Drive Moonachie New Jersey 07074 U S A PIONEER ELECTRONIC EUROPEO Luithagen Haven 9 2030 Antwerp Belgium PIONEER ELECTRONICS AUSTRALIA PTY LTD 178 184 Boundary Road Braeside Victoria 3195 Australia lt ART 467 0 gt F OCT 1979 Printed in Japan CONTENTS pi DISASSEMBLY 5 1 Panel base plate 5 2 D D motor and tonearm 6 PANEL AND BASE PLATE ASSEMBLY PL200 PL300 serere ues ttr ieri 6 2 PL255 PE 409 7 CIRCUIT DESCRIPTIONS 7 1 Block diagram PL 300 PL 400 7 2 Motor operation srs oci orm 7 3 Operation of the PD1003 IC oscillator SEG Asa dup drop io bale bal PL 200 PANEL FACILITIES ss ses PL 255 PANEL FACILITIES 3 casas kun PL 400 PANEL FACILITIES PL 300 PANEL FACILITIES osse 7 4 Operation of the PA2004 IC comparator ceri asera bi ta sea 7 5 Operation of the PA2005 IC drive COMET se ea mme m Ee ES 7 6 Block diagr
13. ON 16 5V REVERSE ROTATION PREVENTION START STOP CONTROL QUICK STOP TIMING VOLTAGE STABILIZER 21 8 MECHANISM DESCRIPTIONS 8 1 PL 200 MECHANISM OPERATING The PL 200 is equipped with auto return only Fig 8 1 shows the PL 200 in the stationary state with the tonearm back in the arm rest Gear A Motor Plate B Lever Microswitch Lever B Fig 8 1 START OF PLAY 1 When the tonearm is moved across to the disc the PU plate located below in the arm base is also moved 2 Lever A is moved over by pin A connected to this PU plate resulting in lever B being un locked 3 At the same time that lever B is unlocked the microswitch is turned on power on and the motor commences to rotate Lever A Lever B Fig 8 2 22 AUTO RETURN When the stylus enters the disc lead out groove and the auto return detector mechanism is activated the claw of the detector mechanism catches the projecting part of gear B on the center shaft resulting in gears A and B engaging each other and gear B consequently rotating in the counter clockwise direction Plate B is then shifted across towards the tone arm due to the groove in the underneath of gear The edge of plate B pushes against lever C to force the arm elevation upwards Plate B continues to shift across to push against pin B on the PU plate thereby returning
14. TMENT 9 1 STYLUS DESCENT POSITION If the stylus does not descend onto the lead in groove on the record during automatic play adjust as follows 1 Place a 30cm 12 inch LP record on the platter 2 Go through the operation for automatic play once and check the level and direction of the stylus deviation from the norm 3 Return the tonearm to the arm rest with one hand and then adjust the stylus descent position by turning the adjusting screw in the adjust ing hole using the screwdriver When the stylus descends outside the lead in groove turn the adjusting screw clockwise e When the stylus descends inside the lead in groove turn the adjusting screw counter clockwise Each half turn of the adjusting screw moves the starting point about 6mm NOTE Be very careful not to damage the record and the stylus when you are adjusting the position of the stylus de scent Screwdriver Adjusting hole Stylus descends outside Stylus descends inside the groove the groove E 7T G A Fig 9 1 28 9 2 AUTO RETURN ADJUSTMENT 1 2 Turn the auto return adjustment screw full around clockwise Move the tonearm right across towards the center When the auto return adjustment screw is turned back a little at a time counter clockwise the tonearm will commence to return to the outer circumference Stop turning the adjustment screw once the stylus tip is 00mm away from the center s
15. am PL 200 PL 255 MECHANISM DESCRIPTIONS 8 1 PL 200 mechanism operating 8 2 PL 400 mechanical operation ADJUSTMENT 9 1 Stylus descent position 9 2 Auto return adjustment 9 3 D D motor adjustment PL 300 and PLADO de antec a 9 4 D D motor adjustment PL 200 and amie prid See 1 PL 200 PANEL FACILITIES BEFORE CONNECTING CHECK THE FOLLOWING 1 Speed checking window Switch the power to the amplifier off to prevent damage to the speaker system The cartridge furnished with your turntable is an MM type Be sure to use a stereo amplifier which has PHONO input jacks for this type of cartridge NOTE If you are using a low output moving coil MC cartridge you will need a special MC transformer or a head amplifier or a stereo amplifier with a built in MC amplifier CONNECTION PROCEDURE Insert the phono cables white and red into the PHONO input jacks of the stereo amplifier white for left channel into L jack and red for right channel into R jack Platter Rubber platter mat D SPEED SELECTOR BUTTON ace i ea When this button is depressed the platter will rotate at 45rpm Depress for playing 45 rpm records singles or EP s SS exe ess When this button is set to the released posi tion the platter will rotate at 33 1 3rpm Release for playing 33 1 3rpm records like LP S SPEED ADJUSTMENT
16. ation to commence record play Pin E PU plate Plate C Pin A lever D Lever A Lever B Plate C plate spring Lever Microswitch Cam B Cam C Gear B lt Detector assembly 522 Lever BSS aa Gear bU Ww Fig 8 8 Fig 8 9 25 15 When the PU plate completes the lead in opera tion pin E of the PU plate rotates lever E in the counter clockwise direction resulting in lever C separating from the microswitch to leave the motor power on for continued disc play See Fig 8 7 PU plate Pin C Lead in reach Fig 8 10 Cam B PU plate Pin Lead in reach Fig 8 11 AUTO RETURN 1 When the stylus enters the lead out groove at the end of the disc the end of the paly is detected by the detector assembly For details on the operational principles in volved in the auto return detector mechanism refer to the PL 516 Service Manual ART 279 When the claw of the detector assembly catches the motor pinion gear gear B gear com mences to rotate Subsequent operation is the same as during lead in 3 4 8 When gear A commences to rotate plate moves towards the tonearm Cam C then presses against cam D attached to the arm base resulting in the arm elevation being raised Cam C pushes pin C of the PU plate across to the arm rest position Pin E also moves at the same time rotating lever E in the clockwise
17. ction of the hole in the sub panel unit Fig 8 10 And when plate A commences to return towards the center shaft the PU plate moves in a clockwise direction thereby carrying the tonearm across to the record When plate A commences to return towards the rear lever B is also pulled back by the action of spring A and stops when it meets the slider Cam B is also brought to a stop by this action Figs 8 9 11 Lever D Sub panel Cam C 22 Leverp Lever C Spring B 24 Microswitch Fig 8 6 10 The PU plate led in by the lead in latch also 12 Then when plate A returns further towards the stops when it meets cam B Fig 8 11 Then center shaft cam B is rotated clockwise by the when plate A returns further the lead in latch is projection on plate A and lever A is returned opened by the action of the sub panel unit hole towards the rear Lever A and cam B are thus resulting in the release of pin C on the PU plate returned to their original positions to permit Fig 8 13 the tonearm free movement The position where the PU plate stops corre 18 Furthermore plate C presses pin A on lever D sponds to the postion set by the disc size across to the left hand side thereby returning selcor lever D back to its position prior to starting 11 As plate A returns towards the center shaft cam 14 Lever is set by striking against the projection D is released from cam C thereby lowering the on gear arm elev
18. direction Lever E thus pushes lever C to the right Just before plate A reaches the end of its move ment across towards the tonearm pin C of the PU plate is clasped by the lead in latch due to the action of the sub panel unit hole When plate A starts to return towards the center shaft the lead in latch holding pin C is opened again by plate D thereby releasing pin C to permit the tonearm to return the arm rest fig 8 13 As cam C returns to the left hand side cam D disengages cam C resulting in the arm elevation being lowered to drop the tonearm back into the arm rest When plate A approaches its original position plate C is pushed to the left by cam C fixed to plate A resulting in the microswitch being turned off by lever C to turn the motor off Fig 8 13 26 REPEAT OPERATION When the repeat button is pressed during record play the control base unit will be as shown in Fig 9 2 Lever D will thus not to move any further left than a pre determined position After the end of the lead in operation the auto return operation commences when the end of record play is reached 1 2 H At the start of the auto return operation cam rotates to move plate A towards the right Cam C pushes against cam D to raise the arm elevation Cam C pushes pin C of the PU plate to the right When cam C reaches across to the right hand side the lead in latch grasps pin C of the PU plate resulti
19. e coils These Hall element outputs are generated by the rotational action of the rotor as shown in Fig 7 9 These signals are thus used in switching the drive circuit also in PA2005A to change the direction of current flow in the coils and thereby determine whether an N or pole is generated or whether the coil is switched off actual rotation this happens as follows As the robor side of coil L becomes a south pole that of L becomes north and Le neutral Repulsion between the S pole at LA and the rotor S pole and attraction between the Lg N pole and the rotor S pole exert a propulsive force on the rotor As the rotor turns through 15 of arc the output from the Hall elements changes Lg now enters OFF state Lc becomes a pole and LA a S pole The Lc N pole now attracts the rotor S pole and the L4 S pole attracts the rotor N pole Rotation continues Correspondences between rotor positions and coil polarities are shown in Fig 7 8 a f Fig 7 2 Fig 7 3 Fig 7 3 Fig 7 3 b Fig 7 3 f 3 Speed Detection Section 1 The speed detection plate has rows of detection patterns 2 The bottom surface of the rotor is magnetized with 200 magnetic poles and these rotate at a short distance above the speed detection plate 3 The output voltage from the detection patterns has a frequency of 55 5Hz at 33 1 3 rpm and of 75Hz at 45 rpm 4 The signal is supplied to IC PA2004
20. e motor commences to rotate the motor pinion gear gear B catches the claw of the detector assembly and gear A and gear B engage each other resulting in gear A rotating in the counter clockwise direction Fig 8 8 5 And since gear A commences to rotate plate A moves towards the tonearm resulting in the plate A projection point A being pressed against cam B to turn the plate in the counter clockwise direction Fig 8 9 Plate A makes a round trip by tracing the heart shaped groove formed in the underneath of gear A Gear Motor RS Detector ass y Spring A Lever F 6 When cam B rotates counter clockwise lever B is moved forwards by spring action in the direc tion of the arrow And while plate A is being moved across to the tonearm lever B is being pulled forwards to reach the state shown in Fig 4 The slider stops at the position selected by the size selector And although cam B con tinues to press against lever A excess stroke action by lever B at this time is absorbed by the flexible spring When plate A moves towards the tonearm cam C fixed to the right hand of plate A presses against cam D attached to the arm base Fig 8 10 Cam D thus rotates in the clockwise direc tion thereby lifting the arm elevation and resulting in the raising of the tonearm Just before plate A completes its movement across towards the tonearm pin C of the PU plate is clasped by the lead in latch due to the a
21. ed If it is set to DOWN for record play the tonearm will be lowered onto the surface of the record and play will begin ANTI SKATE KNOB This knob is used to cancel out the harmful skating force which is generated during record play For further details see ANTI SKATING ADJUST MENT ARM REST CLAMPER The arm rest supports the tonearm when it is not being used Set the tonearm on its rest when it is not playing re cords Clamp it into position if you don t have any im mediate plans to play records PLATTER RUBBER PLATTER When the tonearm is moved and power is supplied to the turntable the platter will start rotating at the set rotation speed The rubber platter mat stabilizes the records and also absorbs external vibration d DUST COVER Keep this closed unless operating the controls or tonearm or changing over records This serves to keep dust from adhering to the records during record play When fully opened and pulled straight up this dust cover can be re moved from the cabinet 4 PL 300 PANEL FACILITIES BEFORE CONNECTING CHECK THE 2 Connect the ground lead with the Y shaped connector FOLLOWING at the end to the ground terminal Switch the power to the amplifier off to prevent damage 3 Insert the power plug into the convenience AC outlet of to the speaker system the amplifier or a wall outlet The cartridge furnished with your turntable is an MM STEREO AMPLIFIER type Be sure
22. front left hand corner float spring differs from the other 3 Refer to Fig 5 1 for correct mounting procedures Switch the size selector to the 25cm position and release the arm lock Rotate the motor clockwise while pressing down on the center of the arm base and check that the main mechanism has been rest to the sta tionary state During this operation spring B and lever A will engage each other as shown in Fig 6 3 When the start button is then pressed spring A wil be released from the rib to engage the pin on lever D This then completes the assembly of the panel and base plate Spring B Rib Spring A Fig 6 2 Level A Spring B Spring A Lever D Fig 6 3 7 CIRCUIT DESCRIPTIONS 7 1 BLOCK DIAGRAM PL 300 PL 400 T 5 O Q SCHMITT OP AMP TRIGGER REFERENCE VOLTAGE F V CONVERTER BUFFER AMP3 BUFFER AMP4 BUFFER PA2004 33rpm 45rpm i 30V PA2005 k qe Q O POSITION B SIGNAL 20V FORMATION REVERSE ROTATION PREVENTION FWD REW DIRECTION FREQ DIVIDER SELECTOR Q PD1003 VCC STOROBE VCC 7 2 MOTOR OPERATION 1 iL 2 Besides Motor Construction These mot
23. haft Once the above adjustment procedure has been completed check that the tonearm returns automatically as designed Fig 9 2 9 3 D D MOTOR ADJUSTMENT PL 300 L TP1 TP2 AND PL 400 Connect the TP3 and TP4 terminals of the control assembly to the inputs CH1 and CH2 of a dual trace oscilloscope Turn the power on and start the turntable plat ter rotating Adjust VR1 and VR2 of the control assembly so that the rising edge of the waveform on TP3 lies inside the square waveform on TP4 as shown in Fig 9 4 This adjustment is performed from the direction of the turntable base plate as shown in Fig 9 3 Adjust VR1 for 33rpm speed and VR2 for 45rpm 9 4 D D MOTOR ADJUSTMENT PL 200 AND 1 2 3 PL 255 Turn the power on and start the turntable plat ter rotating Turn the speed adjustment knob around to the mechanically center position Adjust VR1 and VR2 in the control assembly so that the stroboscope appears to be stationary Again this adjustment is performed from below Adjust VR1 for 33rpm speed and VR2 for 45 As can be seen in Fig 1 the rotor magnet generates an 8 polar trapezoidal magnetic wave and by phase additions of the coil switch ing waveforms a even torque is obtained 29
24. minal thereby controlling the flow of current in the coils Fig 7 6 A o Control input Control input Control input T T ID ID V 1 T m qa 11 Ti T Fig 7 7 a Fig 7 7 b Fig 7 7 c Fig 7 7 d 19 45 90 135 180 ang 4 1 0 wn c m 5 H E N H B1 H B2 gt H Sw pep a a 5 Hc H Fig 7 8 a m LA HA1 Hg2 E o B gt G z m a La Hg14Hoo a E 9 O Fig 7 8 b Forward Rotation Hci Hai HB1 HB2 Hc2 He 1 Reverse Rotation CD Forward Rotation 8 Reverse Rotation Fig 7 9 eo 7 6 BLOCK DIAGRAM PL 200 PL 255 T 5 O TRIGGER p STET pum NOTE The DD motor employed in the PL 200 and PL 300 models operates in much the same way as the DD mo tor in the PL 255 and PL 400 models See pp 14 20 for details 3 2 CONVERTER B BUFFER BUFFER AMP2 AMP4 18 16 5V POSITION SIGNAL FORMATI
25. ng in the tonearm being moved across to the disc The main difference here to the auto lead in operation is that pin A of lever C pushes plate D when the repeat button is pressed resulting in the lead in latch not being opened by plate D as occurs during auto return Consequently the tonearm does not stay at the arm rest but proceeds to move back towards the record for repeated play Subsequent operations are the same as during normal autolead in operation INTERRUPTION OF RECORD PLAY Press the START STOP button Pin A of lever D pushes plate C to the right resulting in the plate C plate spring forcing lever A upwards And this in turn repels the detector assembly Subsequent steps are the same as steps 3 to 10 described under auto return MANUAL START AND STOP When the tonearm is lifted over to the disc by hand pin E of the PU plate rotates lever B in the clockwise direction Lever B is thereby disengaged from lever C switching the micro switch on to start the motor When the tonearm is lifted off the record during play and returned to the arm rest pin E of the PU plate rotates lever B in the clockwise direc tion and this lever thus presses against lever C When lever C then makes contact with the microswitch pressing the microswitch push button th motor is subsequently turned off e Push switch repeat switch Spring B Fig 8 14 Pin A lever C Plate D Fig 8 16 9 ADJUS
26. ors are flat type 8 pole 6 coil slotless Hall motors the 3 phase Y connected windings each motor is equipped with 3 phase detector Hall elements positioned at intervals 60 apart These Hall elements generate Hall voltages which vary in level according to strength and direction of magnetic flux changes induced by the rotating rotor An independent FG magnet used to detect speed changes has been positioned on the outside of the rotor magnet This FG magnet has been designed with 200 magnetic poles and rotates opposite a printed coil mounted on part of the circuit board As the magnet rotates an AC current signal is generated and is used for speed detection purposes As can be seen in Fig 7 l the rotor magnet generates an 8 polar trapezoidal magnetic wave and by phase additions of the coil switching waveforms a even torque is obtained Fig 7 1 2 Principle of Motor Rotation 1 Assume that the rotor has stopped at the po sition as shown in Fig 7 2 2 In this position Hall element HA is located 74 half way between an S pole and N pole on the rotor while HB and HC are opposite an N pole and S pole respectively In 7 8 10 tis 12 If the power is then turned on the Hall element outputs will be as indicated in Fig 7 8 The Hall element outputs are applied to the position signal forming circuit PA2005A resulting in the switching of the current flow ing through the driv
27. rm signals is displaced bv 120 from each other When the step waveform signals at position 1 in Fig 7 7a are applied to the drive circuit terminals a b and c the potential at terminal a will be lowered resulting in Q2 being turned on The potential at terminal b will be raised resulting in Q6 being turned on but the potential at terminal c will remain at the reference level voltage the bias settings for Q4 and Q7 have been designed to prevent these 2 transistors from operating when a reference level voltage is applied Vcc will thus be applied across the Q2 coil LA coil Lg 2 Q6 route thereby pro ducing an S polarity in La and an polarity in Lp 5 Once the magnetic field is generated the rotor will commence to rotate After the rotor turns through 15 the signals at position Fig 7 7b will be applied to terminals a b and c thereby resulting in a change in the flow routes of the drive currents After the rotor turns through another 15 the signals shown at position III in Fig 7 7 c will be applied again resulting in changes in flow routes of the drive currents For every 15 that the rotor turns through the flow routes for the drive currents will change as shown in Figs 7 7d 7 Te and 7 7f finally returning to the routes shown in Fig 7 7a again A control voltage generated by the forward reverse direction discriminator indicator circuit is applied to the control input ter
28. to use a stereo amplifier which has PHONO input jacks for this type of cartridge NOTE If you are using a low output moving coil MC cartridge you will need a special MC transformer or a head amplifier or a stereo amplifier with a built in MC amplifier CONNECTION PROCEDURE 1 Insert the phono cables white and red into the PHONO input jacks of the stereo amplifier white for left channel into L jack and red for right channel into R jack Phono input jacks AC outlet Dust cover Platter Rubber platter mat Anti skate knob Strobe light D CUT BUTTON 8 ARM ELEVATION LEVER If this button is depressed while the record is playing the UP Y tonearm automatically returns to the arm rest and the power to the turntable is cut off When this lever is set to this position the tonearm will rise Set it to UP before record play and when you want to stop record play while a track is being played or when you want to change over to a different track SPEED SELECTOR BUTTON 48 When this button is depressed the platter DOWN Y When the lever is set to this position the will rotate at 45rpm Depress for playing 45 tonearm will be lowered If it is set to rpm records singles or DOWN for record play the tonearm will be DE a acr When this button is set to the released posi lowered onto the surface of the record and tion the platter will rotate at 33 1 3rpm play will begin
29. ton is set to the release position the platter will rotate at 33 1 3rpm Release for playing 33 1 3rpm records like LP s 7 TONEARM This tonearm is designed to apply the correct tracking force to the cartridge and to keep this force at the precise level for faithful tracking of the record grooves It also has the job of switching the power on to the turntable When the tonearm is moved from the arm rest to the platter the power comes on the strobe lamp lights up and the platter rotates When the tonearm is returned to the arm rest the power to the turntable is cut off the strobe light goes off and the platter stops rotating 8 ARM ELEVATION LEVER UP xy When this lever is set to this position the tonearm will rise Set it to UP before re cord play and when you want to stop re cord play while a track is being played or when you want to change over to a differ ent track When the lever is set to this position the tonearm will be lowered If it is set to DOWN for record play the tonearm will be lowered onto the surface of the record and play will begin 8 ANTI SKATE KNOB This knob is used to cancel out the harmful skating force which is generated during record play 10 ARM REST CLAMPER The arm rest supports the tonearm when it is not being used Set the tonearm on its rest when it is not playing re cords Clamp it into position if you don t have any im mediate plans to play records PLATTER RUBBER P
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