Technics SL-P222A - Page 37

SL-P222A
m@ TECHNICAL INFORMATION
Explanation on the CDM4 mini system and
servo circuit for service engineers
1.System Configuration |
1-1.Block Diagram Rough
TDA8809
Photo Diode
Signal
Processor
Focus Radial Radial
: Focus Motor
CDM4 mini «—————» Servo Circuit
Optical
Pick-up
Radial Error
Processor
® Refer to the page 18 and 19.
2.Rough Explanation of the Functions
of the CDM4 mini System Part.
2-1.Servo electronics CDM4 mini system.
TDA8808:| bipolar photo diode signal TDA8809:| bipolar radial error
processor processor
e Photodiode signal preamplifiers :
with separate h.f. and d.c. e Tracking error processor with
a.g.c. for optimum generation of automatic asymmetry control.
the h.f. data signal and the ea.g.c. circuitry with automatic
focusing/tracking error signals. start-up wobble generator.
e Tracking error signal amplifier. e Tracking control for fast
e Focus error signal processor with forward/reverse scan, search,
focus normalizing and start-up repeat and pause functions.
circuit. ® Low current consumption: 10mA
® Data equalizer. (8v - 14V).
h.f. level and track-loss
detectors.
e Regulated supply for the reading
laser diode.
® Low current consumption: 15mA (8V
-T4V).
hp