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● Description of Power supply circuit
When the projector is standby mode, IC301(Main CPU) is not working and IC4801(Sub CPU) is only working for
saving energy.
When the projector is connected to outlet with AC power cord and the Mains SW is switched to ON, SS5V line is
supplied to to standby circuit, including IC4801. IC4801 is waiting for the POWER ON-OFF key input or remote
control signal.
When the projector is turned on, "PWR_SW" signal (Power ON:H) from pin 12 of IC4801 is sent to the
UNIT_POWER, and then the switching power supply circuit starts operation. "MAINON_SW" signal (Lamp ON:H)
from pin 80 of IC301 is also sent to UNIT_POWER, and then the lamp power supply circuit starts operation.
The "5V_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
temperature 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 "MAINON_SW" signal (Lamp OFF:L) and "PWR_SW" signal (Power OFF:L) are
supplied to the UNIT_POWER to stop the power supply operation, and the lamp operation is stopped with
"LAMP_SW" signal (Lamp OFF:H).
Power Supply Lines
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