3-3. CIRCUIT DESCRIPTIONYD-26 board
YD-26 board demodulates Y, R-Y, B-Y, CAM SYNC and
CT-181 boardSKIN GATE. This circuit consists of cable length detection
CT-181 board employs RF system circuit that is consists ofcircuit, cable length compensation circuit and these
RETURN VIDEO modulation circuit and PROMPT VIDEOdemodulation circuits. The cable length detection detects
modulation circuit (It becomes AUX VIDEO demodulationfrom amplitude of Y modulated wave. In accordance with
circuit by switching.) and microcomputer system circuit thatthis, the cable compensation circuit compensates the
controls the system.amplitude and phase matching as cable length to modulated
wave of Y or differential signal. After that, they are
Microcomputer system circuit section :respectively demodulated in demodulator circuit.
The program is written in the ROM (IC1022) that is inserted
to socket (CNI 1). ROM of built-in microcomputer is not
used. Input and output of control signals between each boardES-20 board
in CCU (included in COU) and each board are performed byThis board produces VBS and RGB signal from the Y, R-Y,
serial data of 16 bit via I/O EXPANDER (IC1028). There areand B-Y signals sent from the YD-26 board, switches these
four communication channels with outside. The SCI-1 andsignals, and outputs them as WF and PIX signals. This
SCI-2 built-in microcomputer communicate with CA (viaboard also generates each sync signal and color bars signal.
modulation and demodulation circuit ) and RCP (via RS-232C
driver). The external SCI (IC1024 and 1025) communicates
with command link (RS-232C-1 and RS-232C-2 on the rearAU-234 board
panel).This board inputs and outputs an INCOM signal on the front
panel, displays tally signals, and turns on and off the power
The RF system circuit section :of camera.
RETURN VIDEO modulation circuit frequency-modulates
the input signal (VBS) from RETURN VIDEO 1 or 2, and
sends to the CA. Change of RETURN VIDEO 1 or 2 isIO-140 board
switched by RETURN 1 and 2 changing switch on the CA.This board mixes the RF signal between CA and CCU with
The PROMPT VIDEO modulation circuit amplitude-the power of the camera.
modulates the input signal (VBS) from PROMPT VIDEO on
the rear panel, and sends to the CA. The PROMPT VIDEO
modulation circuit becomes AUX VIDEO demodulation
circuit by switching S2002 and connecting RF coaxial cable to
CN3 and CN8. (It is needed to change on the YD-25 board of
CA.)
Demodulated AUX VIDEO is outputted from PROMPT
VIDEO on the rear panel.
AA-90 board
This board demodulates the RF signal of MIC1, MIC2,
INCOM, CAM DATA and TONE sent from the CA,
modulates a PGM signal, the INCOM signal and control data
send to the CA. And also, this board switches the INCOM
line, and switches the input /output of each audio signals.
CCU-TX7(E)/V1
3-3 |
ACEC
