Sanyo VM-EX70P Adjustment Manual

7-4-2. Speed and Phase Detection and Servo SignalGenerationDetection of the phase and speed and processing of theservo signal are carried out by CXP80724 in the samemanner as the drum servo system.Fig. 7-5. shows a diagrammatical representation of theprocessing inside the IC.The C FG input to Pin @ is divided by n, and then phaseand speed detection of the (CFG/n} signal are carried out.(The d ivision ratio is n = 1 for normal playback.)The phase detection in both the recording mode and theplayback mode are processed in exactly the same way as inthe drum system.After both data have been added, the signal is DAconverted and output from Pin @ as the PWM wave (CAP.PWM) .7-4-3. Capstan Motor DriverThe LB1 857M (IC361 ) is used as the capstan drive IC.7-4-4. Control Signal and Signal Adjustment[Capstan driver control signal]This is output from CXP80724 and input to LB1 857M.CAP F/R : Pin @Input LP : Forward directionIC351 CXP80724CFGATFERROR1 /NNNDSPEEDD ETECT(REC PLAY N=1 )CUE N=9REV N=7PHASEDETECTSERVOPROCESSFig. 7-5. Capstan Servo Processing Circuit- 4-46 -CAP. PWM