NEC NEC-FA150ATUA, Руководство по обслуживанию

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Page 2 Circuit Description
NEC-FA150ATUA
7.4 7.4
7.4 7.4 7.4
OVP OVP
OVP OVP OVP
: If +5V goes up too much, the induced voltage on pin 4 of T802 becomes lar : If +5V goes up too much, the induced voltage on pin 4 of T802 becomes lar
: If +5V goes up too much, the induced voltage on pin 4 of T802 becomes lar : If +5V goes up too much, the induced voltage on pin 4 of T802 becomes lar : If +5V goes up too much, the induced voltage on pin 4 of T802 becomes lar
ge also. Suppose that it is ge also. Suppose that it is
ge also. Suppose that it is ge also. Suppose that it is ge also. Suppose that it is
over 22 volts, ZD803 conducts, Q806 is triggered on, pin 1 of I801 is pulled down to ground, the pulse train over 22 volts, ZD803 conducts, Q806 is triggered on, pin 1 of I801 is pulled down to ground, the pulse train
over 22 volts, ZD803 conducts, Q806 is triggered on, pin 1 of I801 is pulled down to ground, the pulse train over 22 volts, ZD803 conducts, Q806 is triggered on, pin 1 of I801 is pulled down to ground, the pulse train
over 22 volts, ZD803 conducts, Q806 is triggered on, pin 1 of I801 is pulled down to ground, the pulse train
at pin 6 goes down to zero, shutting Q803 of at pin 6 goes down to zero, shutting Q803 of
at pin 6 goes down to zero, shutting Q803 of at pin 6 goes down to zero, shutting Q803 of at pin 6 goes down to zero, shutting Q803 of
f completely f completely
f completely f completely f completely
. .
. . .
7.5 7.5
7.5 7.5
7.5
SCP SCP
SCP SCP
SCP
: If output terminal is short to ground, photo transistor does not conduct, hence Q805 does not conduct : If output terminal is short to ground, photo transistor does not conduct, hence Q805 does not conduct
: If output terminal is short to ground, photo transistor does not conduct, hence Q805 does not conduct : If output terminal is short to ground, photo transistor does not conduct, hence Q805 does not conduct
: If output terminal is short to ground, photo transistor does not conduct, hence Q805 does not conduct
neither neither
neither neither neither
. The reference v5V at pin 8 begins to char . The reference v5V at pin 8 begins to char
. The reference v5V at pin 8 begins to char . The reference v5V at pin 8 begins to char . The reference v5V at pin 8 begins to char
ge on C829 and activates Q806 to conduct, pulling ge on C829 and activates Q806 to conduct, pulling
ge on C829 and activates Q806 to conduct, pulling ge on C829 and activates Q806 to conduct, pulling ge on C829 and activates Q806 to conduct, pulling
pin 1 down to ground, shutting Q803 of pin 1 down to ground, shutting Q803 of
pin 1 down to ground, shutting Q803 of pin 1 down to ground, shutting Q803 of
pin 1 down to ground, shutting Q803 of
f completely f completely
f completely f completely
f completely
. .
. .
.
LCD 1550M Power Board Block Diagram
Line Filter
Rec.
&
Filter
Power
Transformer Output Rec. & Filter
PWM Driver
FB
3. On-screen circuit (Circuit diagrams Main PWB 3/6)
I305 (M66611) Embeded function.
OSD (character pattern display controller) is a module by which the character data beforehand prepared on the normal
display data is inserted (display) in an arbitrary position. SRAM can be built into internally for the character storage
and it is possible to compose the flexible data of the user side.
The outline is shown in Table 1.1.