Epson EMP-7300, Руководство по обслуживанию

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2-6
REV.A
* The input signal from the safety switch is prepared for the protection of over heat. It
shuts the supply of AC power with overheat condition. Safety switch is mounted on
the light guide unit closed to the lamp inner housing.
(2) Outline of function
* The Interlock switch is built for the safety purpose.
* The Interlock switch is accordingly work with the lamp cover at the bottom of main
chassis. It is normally at the ON position. It will shut the AC power by opening the
lamp cover.
* The cable of the power supply unit is connected to CN 600 on the CD10MA board.
Additionally, the following voltage and signal are connected to CN 800(801):
DC output (+3.3/+5/+12/+22V),
PWDS signal for the power down detection,
PWON signal for power on/off.
Lamp status signal (LPST),
Power on/off signal (BACT).
Caution:
If the AC power cable is still connected after the power is shut off, +3.3V background
voltage is supplied to the CD10MA board via CN 600. The background voltage is
subsequently supplied to the power on/off circuit.
* The filter/rectification circuit work to neglect noise on the AC line and generate DC
voltage for the regulator.
* The regulator generates the various level of DC voltage as shown in the below table
in the switching regulator. The regulator detects the voltage output level at the +5V
line and feed back to the switching circuit to maintain the output level stable
regardless the load variation.
Each output voltage level is not the subject of adjustment.
Table2- 2 Output specifications
Power source +5V +3.3V +12V +12FV +22V
Output voltage accuracy (%)
±
5
±
5
±
5
12.0-13.8V 19.0-24.0V
Ripple (mV p-p) 200 100 100 400 400
Ripple/ Spike(mV p-p) 200 100 100 400 400
Output current Min(A) 1.0 0.3 0.2 0.05 0.0
Rated (A) 2.4 2.0 1.0 1.5 0.3
Peak(A) - - - 2.0 -
Overvoltage protection +7V +4.6V - +16V +30V
Overcurrent protection Transient
(Note) Distortion Distortion Transient
(Note) Transient
(Note)
Use Logic circuit Logic circuit Analog circuit
for LCD Fan/Audio
circuit Light valves
NOTE : Protection is the transient detection type, it is recoverable with power on.