1 - 44
1.8.4. Detailed description of each circuit
1.8.4.1
Power input section
The 12VDC output from the power board (PWB-POWER) is turned ON and OFF with the FET
switch (IC703), and is supplied to each oscillation circuit.
The IC703 (FET switch) is turned ON and OFF by turning Q705 (digital transformer) ON/OFF
with the signal (P_INVT) from the microcomputer.
1.8.4.2 Lamp drive circuit section
The lamp is driven with the self-exciting resonance circuit (royer circuit). For dimming, the
PWM (Pulse Width Modulation) method that changes the duty ratio by turning the switching
transistor base current ON and OFF is used.
Thus, the brightness can be changed with the Duty (PWM method) of PWM pulse signal (J703
pin 7: DUTYCINV) from ASIC.
1
2
1
3
4
6
2
5
5
J703
12V
12V
P_INV
Iin
Oscillation circuit 1
Oscillation circuit 2
F701
F702
IC703
HAT1021R
Q705
DTC143EKA-T
Source
Drain
R702
1/16W 4.7K-J
R701
1/16W 4.7K-J
R718
1/16W 220-J
7
8
Gate
12V
DUTYCINV
C701
T701
C703
SL6.3kV
15pF-J
C704
SL6.3kV
15pF-J
Q701
Q702
Q706
Q708
L701
C707
C710
C711
B50V
102-K
R708
R709
R714
R703
R705
R704
Summary of Contents for LCD1550X-BK
Page 88: ...SCHEMATIC DIAGRAM POWER LCD1550X Normal Power Save 1ch Pin 4 2ch Pin 1 3ch Pin 2 4ch Pin 5 ...
Page 89: ...SCHEMATIC DIAGRAM PWB MAIN POWER LCD1550X ...
Page 90: ...SCHEMATIC DIAGRAM PWB MAIN INPUT LCD1550X ...
Page 91: ...SCHEMATIC DIAGRAM PWB MAIN SYNC LCD1550X ...
Page 92: ...SCHEMATIC DIAGRAM PWB MAIN TMDS LCD1550X ...
Page 96: ...SCHEMATIC DIAGRAM PWB MAIN ASIC LCD1550X ...
Page 97: ...SCHEMATIC DIAGRAM INVERTER LCD1550X 1ch Q701 B 2ch Q702 B ...
Page 98: ...SCHEMATIC DIAGRAM PWB SW LCD1550X ...
Page 100: ...SCHEMATIC DIAGRAM POWER LCD1550X ...
Page 101: ...SCHEMATIC DIAGRAM PWB MAIN POWER LCD1550X ...
Page 102: ...SCHEMATIC DIAGRAM PWB MAIN INPUT LCD1550X ...
Page 103: ...SCHEMATIC DIAGRAM PWB MAIN SYNC LCD1550X ...
Page 104: ...SCHEMATIC DIAGRAM PWB MAIN TMDS LCD1550X ...
Page 105: ...SCHEMATIC DIAGRAM PWB MAIN MC LCD1550X ...
Page 106: ...SCHEMATIC DIAGRAM PWB MAIN ASIC LCD1550X ...
Page 107: ...SCHEMATIC DIAGRAM INVERTER LCD1550X ...
Page 108: ...SCHEMATIC DIAGRAM PWB SW LCD1550X ...
Page 155: ......
Page 156: ......
Page 157: ......
Page 158: ......
Page 159: ......
Page 160: ......
Page 161: ......
Page 162: ......
Page 163: ......
Page 164: ......
Page 165: ......
Page 166: ......
Page 167: ......
Page 168: ......
Page 169: ......
Page 170: ......
Page 171: ......
Page 172: ......
Page 173: ......
Page 174: ......
Page 175: ......
Page 176: ......
Page 177: ......
Page 178: ......
Page 179: ......