![Toshiba CF35E50 Скачать руководство пользователя страница 83](http://html.mh-extra.com/html/toshiba/cf35e50/cf35e50_technical-training-manual_1138360083.webp)
83
first.
7. OVER CURRENT PROTECTION
CIRCUIT
1. Outline
If main power (125V) current increases abnormally due to
components failure, there is possible danger of the secondary
damage like failure getting involved in other part failure, and
abnormal heating. To prevent this, over current protection
circuit is equipped, which detects current of main B line to
turn off power relay in abnormal situation.
2. Operation
Fig. 11-19 shows over current protection circuit. When the
current of main B line increases abnormally due to the
shortage in load of main B line, voltage drop arises across
R470. By this voltage drop, when base-emitter voltage of Tr
8 in protector module (Z801) becomes appprox. 0.7V or
more, Tr 8 turns on, and the voltage by divided ratio of R15
and R16 is applied to cathode of ZD4. When this voltage
becomes higher than zener voltage of ZD4, ZD4 turns on to
supply base current to base of Tr 6 via R14. This causes Tr
5 ON and voltage at pin 16 of Z801 becomes Low. Therefore,
QB30 and Q843 turns off to set SR81 OFF. Tr 6 and Tr 7 in
Z801 are in thyristor- connection, and power 5V-1 supplied
at pin 15 keeps protection operation for standby power until
main power switch is turned off. During circuit operation,
power LED near main power switch blinks in red. Caution :
Fig. 11-19 Over current protection circuit
Z801
PROTECTOR MODULE
16
15
17
2
1
5V
MICON
QA01#7
RELAY
SR81
Q843
R830
Q830
MAIN B
R470
F470
To T461
R479
R472
C472
R16
R15
R14
R12
R11
R9
R10
ZD4
C1
Tr6
Tr5
Tr7
Tr8
Z801
PROTECTION MODULE
Содержание CF35E50
Страница 6: ...6 SECTION I OUTLINE ...
Страница 13: ...13 7 CN32D90 BLOCK DIAGRAM ...
Страница 16: ...16 SECTION II TUNER IF MTS S PRO MODULE ...
Страница 24: ...24 SECTION III CHANNEL SELECTION CIRCUIT ...
Страница 41: ...41 SECTION IV AUDIO OUTPUT CIRCUIT ...
Страница 44: ...44 SECTION V A V SWITCHING CIRCUIT ...
Страница 47: ...47 SECTION VI VIDEO PROCESSING CIRCUIT ...
Страница 52: ...52 SECTION VII V C D IC ...
Страница 55: ...55 SECTION VIII PIP MODULE ...
Страница 58: ...58 SECTION IX SYNC SEPARATION H AFC H OSCILLATOR CIRCUITS ...
Страница 63: ...63 SECTION X VERTICAL OUTPUT CIRCUIT ...
Страница 69: ...69 SECTION XI HORIZONTAL DEFLECTION CIRCUIT ...
Страница 85: ...85 SECTION XII DEFLECTION DISTORTION CORRECTION CIRCUIT Side DPC Circuit ...
Страница 92: ...92 SECTION XIII CLOSED CAPTION EDS CIRCUIT ...
Страница 98: ...98 SECTION XIV POWER CIRCUIT ...
Страница 109: ...109 SECTION XV DSP CIRCUIT ...
Страница 125: ...125 SECTION XVI FAILURE DIAGNOSIS PROCEDURES ...
Страница 139: ......