Definition:
The "Focus coil" power supply (PS2) is producing more than 120 VDC or less than 42 VDC.
Theory:
The "Focus Coil" power supply provides about 68 VDC to the focus coil to focus the electron beam in the klystron. The focus coil power supply is turned on 2 secconds before the rest of the modulator is enabled at HVON time. Sampling and detection of a voltage fault is performed within the supply itself. Current fault detection is performed by the "Focus Coil" current Meter.
Sampling Point(s):
The voltage is sampled internally by the power supply (fig 11-3 sheet #5, upper right)
Detection/Threshold Point(s):
The sample is detected internally by the power supply (lower right of fig 11-3 sheet 7).
Supporting Indications:
The E/I meter position #9 displays a abnormal voltage.
"Focus coil" current meter (A1M2) displays a abnormal current level.
Conflicting Indications:
An over voltage condition should shut down the the power supply. This would make the E/I meter show a lack of voltage when the problem was too much voltage.
A high internal current level (>35 Amps) would also shut the power supply down.
Supporting Documentation:
EHB 6-511
Last Updated on June 17, 1998