A2B2 through contacts 1 and 4 of de-energized relay A1K4. Relay A1K4 is maintained de-energized
through time out timer A1TMR for approximately 18 minutes to apply 115 VAC to operate the blower for
cooling. If the searchlight remains in STANDBY for longer than 18 minutes, relay A1K4 will energize and
blower power will be cut off.
When remote control panel STANDBY/ON/IGNITE switch A3S1 is positioned to ON main contactor relay
A1K1 energizes. With A1K1 energized, 80 VDC is initially applied to the anode of xenon lamp A2DS1 on
the searchlight head assembly. The 80 VDC is also applied through resistor A1A2R1, diodes A1A2CR1
and A1A5CR2 and capacitor A1A2C1. Diode A1A2CR2 is a 50V zener diode which will hold the voltage
to igniter relay A1K2 at 50V. Igniter relay A1K2 energizes and remains energized for approximately 40 ms
or 1RC time constant of capacitance of A1A2C1 and the DC resistance of igniter relay A1K2. During this
period 115 V is applied to chopper assembly A1A1 which produces pulses that are applied to the primary
winding of high voltage transformer A2T2. The secondary winding of high voltage transformer A2T2, in
conjunction with capacitor A2C1 and spark gap A2A2, then produces 6KV pulses which are applied to
step up transformer A2T1 resulting in approximately 30KV pulses. The 30KV pulses are then applied to
the cathode of xenon lamp A2DS1. The 30KV pulses arc across the lamp to the anode allowing the 80
VDC from capacitor A1C1 to discharge through the lamp and ionize the xenon gas. The anode return for
the 30KV pulses is via capacitor A2C4. As soon as the xenon lamp is conducting, the 20 VDC operating
voltage then provides current for xenon lamp A2DS1 operation through shunt resistor A1R1. Capacitor
A2C3, and A1C2 are rf decoupling capacitors, while diodes A1CR3 through A1CR2 are spike suppres-
sors.
Momentarily holding the STANDBY/ON/IGNITE switch in IGNITE will apply +24 VDC to ignite relay A1K2
terminal 1 forcing it to energize. Energizing the relay will again apply 115 V to the chopper assembly as in
the ON position. The IGNITE position is provided as a manual means of igniting the lamp especially dur-
ing very cold weather or where normal lamp aging requires additional ignite pulses.
Once the xenon gas is ionized by the high voltage (30KV) pulse the xenon lamp will conduct at the main
DC operating (20 VDC) levels. The xenon lamp will continue to conduct as long as the main DC operating
voltage is applied to the anode.
The searchlight beam width is controlled via the remote control panel VARIABLE BEAM WIDTH switch
A3S2 which provides 24 VDC and ground return to focus motor A2A1. With +24 VDC and ground return,
the focus motor moves the focusing mechanism attached to the xenon lamp in or out. Setting VARIABLE
BEAM WIDTH switch A3S2 to the up position pr24 VDC to terminal 3 and ground return to termi-
nal 1 of DC focus motor A2A1 driving the focusing mechanism in one direction. Setting VARIABLE BEAM
WIDTH switch A3S2 to the down position re24 VDC and ground return to the terminals 1 and 3 of
focus motor A2A1 thereby reversing the direction of focus motor and the focusing mechanisms.
6-3.
DETAILED FUNCTIONAL DESCRIPTION Using 220 VAC Power Supply.
This functional analysis
is provided to aid the technician in troubleshooting the XR Series 500 Watt Marine Searchlight. The
searchlight is comprised of a Power Supply assembly A1, searchlight head assembly A2, remote control
panel A3, and remote current meter A4. Refer to Figure 9304 7-B for searchlight schematic diagram.
The searchlight operates from a 220 VAC, 60 Hz power source which is applied through a 15 ampere cir-
cuit breaker A1CB1 to transformer A1T1. Transformer A1T1 secondaries are tapped for 24 and 80 VAC.
Transformer A1T1 provides 80 VAC to full wave rectifier A1CR1. The full wave rectifier rectifies the 80 VAC
and initially charges filter capacitor A1C1 to a level dependent upon load. Under minimum load (main con-
tactor A1K1 de-energized or xenon lamp A20S1 not conducting), the main DC operating voltage will
charge capacitor A1C1 to approximately 80 VDC; under maximum load (main contactor A1K1 energized
and xenon lamp A2DS1 conducting), the main DC operating voltage will charge capacitor A1C1 to
approximately 20 VDC. Transformer A1T1 provides 24 VAC to full wave rectifier A1A2CR1 which is recti-
fied to provide relay control power. The 24 VDC is also used for control of beam width.
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