Standby Power Supply And Power On Circuit - Sony KDP-51WS550 Training Manual

When troubleshooting the AX-1 chassis power supply system, keep this sequential DC Start voltage structure in
mind. For example, if the HV power supply fails, it may be actually a failure of the Primary Power Supply, which
supplies the DC Start voltage to the HV Power Supply, or the problem could be further up in the system in the Q-
Box Power Supply, which supplies the DC Start voltage to the Primary Power Supply.

Standby Power Supply and Power ON Circuit

Standby Power Supply
T6101
2
AC
4
A BOARD
MA BOARD
ON/
IC001
46
OFF
MAIN 69
REMOTE
7
MICRO
SIRCS
Reference Figure 3-2
The Standby Power Supply is a simple bridge rectifier and filters power supply consisting of bridge rectifier
D6113 and filter capacitors C6115 and C6110. This circuit produces the Standby 7V (actually ~ 8V to 9.6V)
supply to the 5V regulator IC6109. IC6109 takes the Standby 7V and regulates it down to 5V, which is supplied
to the MA board to power the Main Microprocessor IC0001, HA board to power IR Sensor, and UA board to power
the Control-S circuit. Also note the protect zener diode D6108 (18V) on the input of the 5V regulator IC6109.
Due to its simplistic design, the Standby Power Supply consumes very little current (~ 30mA or ~ 0.4W in standby
mode), which satisfies the constraint of less then 1W power consumption in standby mode to be Energy Star
complaint.
Power ON Circuit
Reference Figure 3-2
The power ON sequence starts with an ON command input from the ON/OFF button (IC0001/pin 46) or the
Remote Control (IC0001/pin 7) to the Main Microprocessor IC0001. Once the ON command is received, IC0001/
pin 69 will output a HIGH (3V), which is applied to the base of Q6102. Q6102 turns ON and goes into saturation
and a ground (through Q6102) is applied to the AC Relay (RY6000) and the base circuit of Q6109.
In standby mode before Q6102 is turned ON, Q6107 (kick transistor) is ON and charges C6120 to 27V. The 27V
is applied to the AC Relay (RY6000). So, once the ground is applied to the relay through Q6102, the relay
energizes with initial current beginning drawn through C6120, which is charged to 27V at that moment. This
provides the AC Relay with a good initial power and current source that enables the TV to turn ONn under low or
varying AC voltage input sources. The AC voltage input from the home outlet can be as low as 85VAC before the
D6113
+
C6115
9
D6116
Q6110
8
D6117
Q6111
7
Q6107
D6114
C6116
R6115
Q6109
D6118
27V
R6126
3V
D6115
Q6102
R6111
FIGURE 3-2 - STANDBY POWER SUPPLY & POWER ON CIRCUIT
STBY 9.6V
ON 8V
IC6109
+
5V REG
C6110
D6108
18V
ZERO_DET
D6120
D6123
RY6000
AC RELAY
+
C6120
STBY 27V
ON 7V
11
3. AX-1 Chassis Power Supplies
Ÿ
MA BRD.
(MAIN MICRO IC0001)
STBY
Ÿ
HA BRD. (IR SENSOR)
5V
Ÿ
UA BRD. (CONTROL-S)
TO MAIN, HV &
D6005
Q BOX POWER
AC RECT.
SUPPLIES
(D BOARD)
TVP16.3-2 1/13/04