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@ Explanation of Block Diagram
(1) Mechanisms section (servo mechanism ass'y,loading
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(3
(4
(5
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mechanism unit)
The unit comprises a pickup, servo mechanism ass'y,
loading mechanism unit, open switch and clamp switch.
Main unit
The main unit comprises a servo circuit, driver circuits,
varipitch circuit, signal processing circuit, DSP circuit
and audio circuit.
The pickup outputs RF signals, focus error signals, and
tracking error signals. The servo circuit controls the fo-
cus servo, tracking servo and carriage servo using these
signals.
The signals needed for the spindle servo are generated
from the EFM to be sent to the signal processor from the
servo circuit.
There are five driver circuits, for focusing, tracking, car-
riage operation, spindle operation and loading.
The varipitch circuit comprises an external crystal oscil-
lation circuit and a PLL circuit, and sends data to the
DSP synchronized with the clock in accordance with in-
structions from the microcomputer. Data processed at
the DSP is sent to the digital filter and DAC. The data is
converted by a D/A converter, and output as audio signal
after passing through a low-pass filter.
* Sub-code signals output from the signal processing cir-
cuit are input to the CD-G decoder circuit. After error
correction, these signals are image-processed, and out-
put as NTSC video signals. (CDJ-500G/KUC type only)
Audio out ass'y
Unbalanced analog audio signals and video signals (in
the NTSC mode) are output from the RCA pin jack that
has a control terminal.
* This assembly has terminals for RF adapter-compat-
ible audio output and DC output (CDJ-500G/ KUC type
only).
Slider ass'y
This has sliding variable resistors having a stroke of 100
mm. A voltage of 0 to +5V is output depending on the
position of the slider knob.
Photo interrupter ass'y
This ass'y outputs a pulse proportional to rotation from
the photo-interrupter that is interlocked with the jog con-
troller.
CDJ-500G, CDJ-500
(6) Control ass'y
This ass'y comprises control buttons, a display and a sys-
tem control microcomputer.
The voltage output from
the slider ass'y is input to the A/D port of the microcom-
puter, and converted to 8-bit digital signals. These in-
structions are sent to a decoder, and are used for control-
ling speed. The microcomputer also controls the display
circuit, decoder and DSP.
1-9
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