User Manual

Chassis Block Diagrams
-89-
UNIT_LAMP BALLAST
1
4
4
3
CN2
K6C
K8L
S5V
CN1 CN3
LAMP
POWER BOARD
MAIN BOARD
PRIMARY CIRCUIT
LAMP_SW
FAN_ERR
LAMP_TX
LAMP_RX
67
LAMP_SW
TX_LAMP
3
1
RX_LAMP
68 4
11
3
8
69
IC801
TV CPU
IC601
P. F . C .
<FA5502>
IC1831
IC1851
K18T
K8S
K18V
K18U
JOINT BOARD
THERMAL SW
SW902
13
13 13
31
ERROR : Open
K18S
COVER SW
BOARD
LAMP COVER SW
SW1861
13
ERROR : Open
ERROR : H
ERROR : L
FULL
BRIDGE
CONTROL
BOOSTER
PWM
FILTER
BUFFER
IGNITION
CIRCUIT
DC INPUT
DC300~380V
18V18V
ECO_mode
H = ECO, L = Normal
LPS_mode
H = LPS, L = OFF
H = Lamp-ON
L = LPS or
Lamp-OFF
Output voltage.
at starting time : 2.4 - 3.6 KV
at normal : AC 70V typ.
Output Frequency : 180 Hz typ.
PC103 PC102 PC101
● Lamp control stage
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
Tu rn ON
Tu rn OFF
LPS Mode
Stable Period
LAMP STATUS TIMING CHART
H = Low, L = High mode
Error Detect Period
Lamp Driving Circuit
Turn PTV on, LAMP_ON signal becomes to "H" and the lamp starts lighting.
The ballast output is about 140W at High and Mid mode, or about 115W at Low mode.
Lamp_Rx/Tx signals between IC801 and the ballast unit control the output of the ballast by UART.
Rx_LAMP signal (lamp error signal) becomes "H" and then the projection TV shuts down.
Turn PTV off, TV CPU shuts down the lamp 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 PTV is turned on during LPS mode, the lamp lights at once.
P. F.C. Circuit
Power factor control (P.F.C.) is performed by IC601
and the peripheral circuits. The output voltage
370V (at AC input = 230V) is supplied to the ballast.
The output voltage is adjusted with VR621.
Lamp Cover Switch and Thermal Switch
When the lamp cover switch or the thermal switch
is open, Lamp_ON signal will be cut off and the
lamp does not light for safety.
● Description