Arc Lamp - JVC 250 Service Manual

Chapter 4---Optical

4.1 Arc Lamp

The Arc Lamp is the beginning of the high intensity Light Path. It is located
inside a housing on the right side of the Optical Support Assembly (see Figure
4-5).
Arc Lamp - Main Functions:
The Arc Lamp is a single component composed of a Xenon gas bulb at the center
of a compound elliptical reflector. It supplies the high intensity white light used
by the projector to put a very bright image on the screen. The expected 50% life
(half of initial light output) of an Arc Lamp is approximately 1000 hours.
Arc Lamp - Inputs
32 kV pulse to light the Arc Lamp Power Supply
!
2 kW constant power during normal operation
!
Arc Lamp - Operation
The Arc Lamp Power Supply and the Igniter Assembly work together to produce
a 32 kV pulse that ignites the Arc Lamp. After the Arc Lamp lights, the voltage
from the Arc Lamp Power Supply drops to a constant 25-31 volts at 70-85 amps.
It will stay at this level during normal Arc Lamp operation.
Arc Lamp - Service Adjustments
When a new Arc Lamp is installed, it will need to be aligned using the Arc Lamp
adjustment fixture located inside the Arc Lamp housing (see Figure 4-2).
Arc Lamp Adjustment
Tools Needed
Large Flatblade screwdriver
4-mm Hex-head wrench
Equipment Needed
Minolta Illumination Meter T-1 or equivalent
To align the Arc Lamp:
1. Remove the front cover (see Section 6.1).
2. Loosen the spider lock down bolt (see Figure 4-4).
3. Power the projector ON and let it run for 15 minutes to stabilize.
4. Verify that the "Shutters on Hide" box is checked in the System-
Preferences menu, then use the RGB key and the HIDE key to hide Red
and Blue. This prevents light coming from the Red and Blue ILA
5. Open the fan door of the Arc Lamp Enclosure housing using the large
Flatblade screwdriver to rotate the retaining screws 90 This gains access
to the three Arc Lamp alignment screws. The Arc Lamp fan disconnects
when this door is opened.
4-2
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Model 250 Service Manual