Advertisement
•
Voltages on the secondary side are as follows: +20 Volts at D811, +10 Volts
at D808, +14V at D810, -22 Volts at D812, +12Vst at Q804.
• Using the output of the D808, a photo diode inside of the IC803 generates
feedback signal bu using optocoupler's photo transistor. This photo transistor
adjusts the control voltage at the IC800 pin3. The voltage at this pin effects
the pwm output frequency on the IC800 pin5. And finally output voltages
reach their correct values by this way.
• Voltage regulator IC805 (LM7805) supplies +5 Volts,
IC807 supplies +5V (off on standby mode),
IC809 supplies +3.3V (by using output of the IC807, off on standby mode),
Q804 supplies +12Vst,
IC806 supplies +12V (off on standby mode),
Q808 supplies -5V,
D812 supplies -22V.
Standby mode controlled by standby control transistors Q805, Q806, Q807.
Standby control signal comes from PL805 connector and generated by 8051
micro controllers.
• –22 Volts is used to feed the VFD (Vacuum Fluorescent Display) driver IC on
the front panel. Using diode R844, –22V is decreased and connected to the
filament winding to produce the DC offset for the filaments.
14.2 FRONT PANEL:
• All the functions on the front panel are controlled by IC1 (ES6008/18) on the
mainboard. Key scanning and IR checking operations on the standby mode
are controlled by IC500.
• ES60X8 IC sends the commands to IC1 uPD16311 via socket PL1 (pins 2,3
and 4).
• There are 16 keys scanning function, 2 LED outputs, 1 Stand-by output and
VFD drivers on IC2.
• Pin 52 is the oscillator pin and is connected via R5 56K.
• LED D5 is bright red in stand-by mode and soft red when the device is on.
• Vacuum fluorescent display MD1 is specially designed for AV1000.
• The scanned keys are transmitted via IC3 to IC1 on the mainboard.
• IR remote control receiver module IC2 (TSOP1836) sends the commands
from the remote control directly to IC1 and IC500.
• Socket PL2 carries the VFD filament voltage and –22 Volts.
14.3 I/Os and Back Panel:
• PL303 connector on the main board carries digital audio and command
signals to Class-D amplifier board (DDX Board). Command signals are
carried by an I
interface. After processing and amplification of audio signals amplificated
audio signals comes to back panel with this order(left to right): Front Left,
Front Right, Rear Right, Center, Rear Left and Subwoofer.
2
C bus and digital audio signals are carried by I
20
2
S bus
Advertisement
