Transmitter A1A1 " Power Supplies - Filament Voltage"
Definition:
A fault condition has been detected in the filament power supply (A1).
Theory:
The filament power supply provides heater voltage to the klystron. The heater/filament voltage is a AC voltage that synchronized with the P.R.F. when the transmitter is firing. The power supply free runs when the transmitter is not firing. The output voltage is monitored internally for a over voltage or under voltage condition. If the voltage is greater than 105 volts or less than 50 volts this alarm is generated. The signal leaves the filament power supply as "SUMVLTFLT" (fig 11-3 sheet #4). The signal is then processed by "control and monitoring".
Sampling Point(s):
The sampled internally by the power supply itself (fig 11-3 sheet #4, top center)
Detection/Threshold Point(s):
The sample is detected in the power supply. Detection of the faulted condition is processed by the "control and monitoring " function on the A3A3 card (upper center of fig 11-7 sheet 9).
Supporting Indications:
The E/I meter position #7 shows a abnormal voltage.
"Filament Supply On" lamp provides indication of internal supply voltage condition.
Filament current meter reading low or none.
The filament current meter's high limit will turn off the filament power supply.
Conflicting Indications:
None
Note: If the filament current went high or a failure in control and monitoring made "RELYDRV"(center, left of fig 11-3, sheet #3) false , the power supply would shut down and the current meter would read a low condition.
Supporting Documentation:
EHB 6-511
Last Updated on June 17, 1998