1-18
1-83.
A HIGH exciter fault signal is also applied to OR gate U13C. U13C will output a HIGH to
inverter U25A. U25A will output a LOW to AND gate U22B. U22B will output a LOW
transmitter operate command to mute: 1) the exciter PWM signal and 2) the power
supply circuit board(s).
1-84.
POWER SUPPLY MONITORING.
The power supply(s) operating condition is monitored
by a power supply status circuit. The following text presents the power supply
monitoring operations.
1-85.
Power Supply Fault.
During a power supply fault condition, the power supply fault status
input will go LOW. The LOW is applied to OR gate U45A. With a LOW ac fail signal
present, U45A will output a LOW to NAND gate U60A. With a HIGH power supply
emergency signal present from U46D, U60A will output a HIGH to latch U48B. U48B
will output a HIGH to: 1) bias driver transistor Q43 off to extinguish the power supply
indicator green LED and 2) NOR gate U52D. U52D will output a LOW to bias driver
transistor Q42 on. This will illuminate the power supply indicator red LED.
1-86.
Power Supply Emergency Condition.
During a power supply emergency condition, the
power supply emergency fault status input will go HIGH. The HIGH is applied to AND
gate U36B. With a HIGH enable failure signal present, U36B will output a HIGH to: 1)
inverter U46D and 2) OR gate U37B. U46D will output a LOW to NAND gate U60A.
U60A will output a HIGH to latch U48B. U48B will output a HIGH to: 1) bias driver
transistor Q43 off to extinguish the power supply indicator green LED and 2) NOR gate
U52D. U52D will output a LOW to bias driver transistor Q42 on to illuminate the power
supply indicator red LED. With a HIGH from U36B applied to U37B, U37B will output a
HIGH emergency off signal to OR gate U37A. This configures U37A and OR gate U13A
to generate a transmitter off signal.
1-87.
Power Supply Maintenance Condition.
During a power supply maintenance condition,
the power supply maintenance fault status input will go HIGH. The HIGH is applied to
NOR gate U52D. U52D will output a LOW to bias transistor Q42 on. This will illuminate
the power supply indicator red LED. With no power supply fault indications, the output
of U48B will be LOW. The LOW bias driver transistor Q43 on to illuminate the power
supply indicator green LED. The simultaneous illumination of the indicator green and
red LEDs will produce a yellow maintenance indication.
1-88.
RF POWER MODULE MONITORING.
The RF power module operating condition is
monitored by an RF power module status circuit. The following text presents the RF
power module monitoring operations.
1-89.
RF Power Module Fault.
During an RF power module fault, the power supply fault status
input will go LOW. The LOW is applied to inverter U46F. U46F will output a HIGH to
latch U48C. U48C will output a HIGH to: 1) bias driver transistor Q41 off to extinguish
the RF power module indicator green LED and 2) NOR gate U52B. U52B will output a
LOW to bias driver transistor Q40 on. This will illuminate the RF power module
indicator red LED.
1-90.
RF Power Module Maintenance Condition.
During an RF power module maintenance
condition, the RF power module maintenance fault status input will go HIGH. The HIGH
is applied to NOR gate U52B. U52B will output a LOW to bias transistor Q40 on. This
will illuminate the RF power module indicator red LED. With no RF power module fault
indications, the output of U48C will be LOW. The LOW will bias driver transistor Q41 on
to illuminate the RF power module indicator green LED. This simultaneous illumination
the indicator green and red LEDs will produce a yellow maintenance indication.