Electrical Circuit Components - Epson EMP-1825 Service Manual

EMP-1825/EMP-1815/EMP-1810

2.2.1 Electrical Circuit Components

The components and their functions are explained below.
Component name
MA Board
PS Unit
PS Ballast
Assy.
Ballast Unit
Control Panel
RC Board
P/S Fan
Lamp Fan
Fans EX Fan
PBS Fan
Intake Fan A/B
TH Board (Lamp
Thermistor)
L/V Thermistor
Sensors
Safety Switch
Lamp Lid
Detection Switch
Lens Shutter Detection Sensor
(Photo Interrupter)
SEIKO EPSON
The circuit board that controls the whole system and functions of the projector.
The main functions are listed below.
• Degitally processes the input data from the external devices.
• Generates the drive signals of the L/V (R/G/B).
• Controls the external I/O interface.
• Drives and controls the Lamp.
• Monitors the sensors' input and controls the internal temperature with the
fans (fan drive control).
Generates and supplies the DC power used in each components from the AC
input.
Generates the power supply to drive the Lamp from the DC power supplied
from the PS Unit.
The control part of the projector located on the Upper Case. Various buttons for
each functions are mounted on the panel.
Receives the IR signal from the remote controler. Mounted at the front and the
back of the projector.
Ventilates the PS Ballast Assy.
Ventilates the Lamp.
Exhausts the heated air generated inside the projector to the outside.
Ventilates the PBS of the Light Guide Unit.
Take in fresh air and ventilate the L/V.
The thermal detection sensor for the Lamp mounted on the Inner Exhaust Duct
around the lamp. , The fans are controled based on the detected thermal data
together with the one from L/V Thermistor explained below.
The temperature around the Lamp exceeds the specified level, the "High Temp
Warning" is issued. If the temperature continues to rise, the projecctor issues
the "High Temp. Error" message with LED indicators and stop the Ballast Unit,
and shuts off the power supply to the Lamp.
The thermal detection sensor for L/V mounted on the POP of the Optical
Engine. The fans are controled based on the detected thermal data together with
the one from Lamp Thermistor explained above. (The function of the ther-
mistor and the warning signs are the same as the Lamp Thermistor above.
Functions as the safety device in the case of the loss of temperature control due
to the failure of the thermistors. This is a detection switch for the prevension of
overheating, and is mounted on the side of the Inner Exhaust Duct. If the inter-
nal temperature exceeds the specified level, the switch cuts off the AC power
supply. The power supply cannot be activated until the internal temperature
drops below the certain level.
Detects the status of the cover for the lamp replacement. If the Lamp Lid
opens, the power supply to the Lamp is cut off. In such a case, the power sup-
ply cannot be activated.
The sensor using a photo interrupter to detect the status of the Lens Shutter.
The "Closed" status is detected when the protrusion of the shutter for detection
blocks the detection light inside the sensor. On the "Closed" Status:
the solid black is displayed.
the audio output switches to the A/V mute mode.
the Lamp turns to the Low Brightness mode.
2-4
CONFIDENTIAL
Function
Revision:C