Power Supply Control
The microprocessor part is supplied with 3.3V and 3.9 V both derived from the
‘MainAux’ voltage via a 3V3 stabilizer (7560) and a diode.
Two signals are used to control the power supply:
•
Stdby_con
This signal is generated by the microprocessor when over-current
takes place at the ‘MainAux’ line. This is done to enable the power supply into
standby burst mode, and to enable this mode during a protection. This signal is
‘low’ under normal operation conditions and goes to ‘high’ (3.3V) under ‘standby’
and ‘fault’ conditions.
•
POWER_DOWN
This signal is generated by the power supply. Under normal
operating conditions this signal is ‘high’ (3.3 V). During ‘standby’ mode, this
signal is a pulse train of approx. 10 Hz and a ‘high’ duration of 5 ms. it is used to
give information to the UOC about the fault condition in the Audio amplifier
supply circuit. This information is generated by sensing the current on the
‘MainAux’ line (using voltage drop across R3564 to trigger Q7562). This signal
goes ‘low’ when the DC-current on the ‘MainAux’ line exceeds 1.6- 2.0 A. It is
also used to give an early warning to the UOC about a power failure. Then the
information is used to mute the sound amplifier to prevent a switch off noise and
to solve the switch-off spot.
Protection Events
Several protection events are controlled byte UOC:
•
BC protection
, to protect the picture tube from a too high beam current. The UOC
has the capability of measuring the normal back level current during the vertical
flyback. So if for some reason the CRT circuit is malfunctioning (i.e. highbeam
current), the normal black current will be out of the 75 µA range, and the UOC
Summary of Contents for 7629
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Page 14: ...AV2 In SVHS Connector Kind Value Symbol 1 gnd v 2 gnd v 3 Y 1 Vpp 75 O j 4 C 0 3 Vpp 75 O j ...
Page 16: ...Figure ...
Page 18: ...Figure ...
Page 48: ...Hardware Alignments Figure Mono Carrier Top View LS ...
Page 76: ...Power Supply Figure Figure ...
Page 101: ...T8 7629 ...
Page 102: ...T8 7629 ...
Page 103: ...T8 7629 ...
Page 104: ...T8 7629 ...
Page 105: ...All Models 7629 PCB Locations ...
Page 106: ...All Models 7629 Power Supply Diagram A1 ...
Page 107: ...All Models 7629 Line Deflection Diagram A2 ...
Page 108: ...All Models 7629 Frame Deflection Diagram A3 ...
Page 109: ...All Models 7629 Tuner IF Diagram A4 ...
Page 110: ...All Models 7629 Video IF And Sound IF Diagram A5 ...
Page 111: ...All Models 7629 Synchronization Diagram A6 ...
Page 112: ...All Models 7629 Control Diagram A7 ...
Page 113: ...All Models 7629 Audio Amplifier Diagram A8 ...
Page 114: ...All Models 7629 BTSC Stereo SAP Decoder Diagram A9 ...
Page 115: ...All Models 7629 Audio Video Source Switching Diagram A10 ...
Page 116: ...All Models 7629 BTSC NDBX Stereo Decoder Diagram A11 ...
Page 117: ...All Models 7629 Front I O Control Headphone Diagram A12 ...
Page 118: ...All Models 7629 Rear I O Cinch Diagram A13 ...
Page 119: ...All Models 7629 PIP Interface Diagram A16 ...
Page 120: ...All Models 7629 CRT Panel Diagram B1 ...
Page 123: ...USED ONLY IN MODELS 27PS60S321 27RF72S325 32PS61S321 7629 PIP Panel Diagram P ...
Page 125: ...USED ONLY IN MODELS PC0125C321 PC0127C321 7629 EPS Panel Schematic ...
Page 126: ...USED ONLY IN MODELS PC0125C321 PC0127C321 7629 Card Interface Schematic ...
Page 128: ...All Models 7629 Main Panel component side ...
Page 129: ...All Models 7629 Main Panel copper side ...
Page 130: ...All Models 7629 CRT Panel component side ...
Page 131: ...All Models 7629 CRT Panel copper side ...
Page 132: ...All Models 7629 Headphone Panel component side ...
Page 133: ...All Models 7629 Side AV Panel component side ...
Page 134: ...All Models 7629 PIP panel component side ...
Page 135: ...All Models 7629 PIP panel copper side ...
Page 136: ...All Models 7629 Top Control Panel component side ...
Page 137: ...All Models 7629 EPS Panel PCB Top View only ...
Page 138: ...All Models 7629 Card Interface Panel PCB Top View ...
Page 139: ...All Models 7629 Card Interface Panel PCB Bottom View ...
Page 140: ...MAIN CABINET EXPLODED VIEW ...