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Chassis Block Diagrams
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-
-
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R
S
Q
S
MUL
OCP.COMP
PWM.COMP
OVP.COMP
ER.AMP
CUR.AMP
OSC
UVLO
REF
ON/OFF
IDET
IFB
IIN-
VDET
OVP
VFB
VIN-
GND
OUT
VC
ON/OFF
VCC
REF
CS
CT
SYNC
11
μ
A
1.55V
1.64V
1.55V
11k
15k
4.85k
0.39V
5V
16.5V/8.9V
3.95V/
2.8V
L
D1
Q
Co
Vo
Vin
Rs
Rg1
C5
Rg2
12
10
13
11
9
8
7
6
5
4
3
2
1
16
14
15
Boost Converter
R4
C1
R3
R2
VR1
R12
R11
R
T
C
T
Current Error Amplifier
Oscillator
Soft Start
PWM OUTPUT
Voltage Error Amplifier
Overvoltage Protection
Multiplier
Output ON/OFF Control
18V
ON : Hi
OFF : Low
Output
Voltage
Adjustment
IC601 FA5502M
LAMP
BALLAST
D2
AC INPUT
FULL
BRIDGE
FILTER
BUFFER
IGNITION
CIRCUIT
RX_LAMP
LAMP ON
GND
TX_LAMP
CONTROL
LAMP
ASS'Y
DC INPUT
DC250~400V
U20B74100
DC+
GND
18V
CN03
UNIT_LAMP BALLAST
CN02
CN01
1
2
3
4
Output voltage.
At the time of a start : 2.4 - 3.2 KVp-p
At the time of stability : AC 70V typ. (50~120V)
Output Frequency : 180 Hz typ.
H : Abnormality
ECO Mode
H : ECO
L : Normal
LPS Mode
H : LPS
L : OFF
H : ON
L : LPS or OFF
DC18V
1
3
4
V
CT
V
CS
V
IFB
OUT
pin
t
t
PWM COMPARATOR TIMING CHART
LAMP_ON
(LAMP CON/SYNC Signal)
LAMP_STATUS
RX_LAMP
(LAMP_LIT Signal)
TX_LAMP
(ECO - LPS Signal)
H
L
ON
OFF
H
L
H
L
t
Turn ON
Turn OFF
LPS Mode
Stable Period
LAMP STATUS TIMING CHART
H = ECO, L = Normal
Error Detect Period
●
Power factor control circuit for Lamp ballast
●
Lamp ballast circuit
NOTE :
Lamp Driving Circuit
Turn on the LCD Projection Monitor, LAMP_ON signal becomes to "H" and the lamp is started to light.
The ballast output is about 130W at NORMAL mode or about 115W at ECO2 mode (55inch typical).
At AUTO mode, IC301 averages the luminance of the input image, then LAMP_PWM signal from IC301 is
supplied to IC1861, and Rx/Tx signals between IC1861 and the ballast unit control the output of the ballast.
Rx_LAMP signal (lamp error signal) becomes "H" and then the LCD Projection Monitor shuts down.
Turn off a LCD Projection Monitor, it shutdowns after the period of LPS mode.
LPS Mode (Low Power Shutdown)
At LPS mode, the ballast output is keeping about 30W for about 4 minutes after turn-off.
When the LCD Projection Monitor is turned on during LPS mode, the lamp is lit at once.
NOTE :
Power factor control (P.F.C.) is performed by IC601 and the peripheral cir-
cuits. The output voltage 370V (at AC input = 230V) is supplied to the bal-
last. The output voltage is adjusted by VR1 as shown below.
S Mode
t LPS
de (Lo
mode
de
ow
w Pow
e, the
o
ow
alla
utdow
outpu
wn
t is keeping about
d
0W f
ab ut 4 m
minutes
r turn-off.
●
Po
ower
o
actor con
ntrol circuit f r Lam
mp ballast
RT
NG CHA
R TIMI
ARATO
COMP
PWM