- 81 -
● Description of Power supply circuit
When the projector is in the super standby mode, the Main power supply circuit is not working. And IC4801(Sub CPU),
remote control, and Power LED are only working for saving the power consumption
When the projector is connected to outlet with AC power cord and the Mains SW is switched to ON, SS3.3V line is supplied
to standby circuit, including IC4801. IC4801 is waiting for the POWER ON/STAND-BY key input or remote control signal.
When the projector is turned on, "STANDBY_SW" signal (Power ON:H) is sent to the ECO POWER board, and then the
switching power supply circuit starts operation. "POWER_ON_SW" signal (Lamp ON:H) from pin 25 of IC301 is also sent to
the POWER board, and then the lamp power supply circuit starts operation.
The "1.8V_SW", "3.3V_SW", "15V_SW" and "FAN_SW" signals are also sent to the power supply circuits.
Power failure protection of secondary power circuit
The projector provides a protection circuit to prevent the secondary failure when the power failure, fans failure or tempera-
ture failure occurs on the projector. The power failure detection lines are connected to the main power supplies. When a
failure occurs, IC301 receives the power failure detection signals "POWER_FAIL" through the power failure detection lines
and "POWER_ON_SW" signal (Lamp OFF:L) is supplied to the POWER board to stop the power supply operation, and the
lamp operation is stopped with "LAMP_SW" signal (Lamp OFF:H).
Chassis Block Diagrams
S5V
5~9
K8A
1.2V_DS
D5282
0.9V_REF_DETECT
IC5203
1.2VDS_ON_PW
1.2VDS_ON_FPGA
3.3VDS_ON_PW
3.3VDS_ON_FPGA
3.3V_DS
D5281
IC5204
1.8V_DS
1.8V_DDR
D5283
IC5207
D5283
1.2V_DS
IC5203
2.5VDS_ON_PW
2.5VDS_ON_FPGA
IC5208
0.9V_DDR
0.9V_REF
IC301
SYSTEM
CONTROL
Power Fail : L
PFAIL_GROUP1
Power supply circuit and Protection circuit (2)
To Next Page
Loading...
