GE_OEC_9600_C-Arms

4 mA Generation
FILAMENT REGULATOR SETUP
Provides the initial setup, regulation and monitoring of the filament regulator output
voltage. The filament regulator is located on the Generator Driver PCB.
When the system is booted, but no X-rays are commanded, the X-ray Regulator kV drive
PAL U7-16 will be a logic low. This disables error amp U15 by holding the contacts (pins
10 & 11) of switch U13 closed. The output of the error amp applied to TP4 should be 0
VDC at this time.
The FIL B CONTROL signal is now applied to the X-ray Regulator R82/U27-6 summing
point unaffected by the output of the error amp. The FIL B CNTRL voltage at TP10 on
the X-ray Regulator PCB and U27-6 of the Generator Driver PCB are shown in Table 2.
Fluoro =
4 VDC with X-rays OFF
0.3 mm Film = 4.4 VDC, Armed 4 VDC
0.6 mm Film = 4.6VDC, Armed 3.5 VDC
Table 2 - Approximate Control Voltages
U27-7, on the X-ray Regulator, provides an approximate +3 to +5 VDC signal (FILREG)
to the filament regulator on the Generator Driver PCB. The Filament Regulator is
comprised of Q10, Q1, Q2 and associated components. The filament regulator supply is
the B+ voltage from the batteries and can be measured at fuse F3
on the Generator Driver PCB.
The FILREG signal from the X-ray Regulator controls the filament regulator output to the
proper voltage for the selected X-ray mode as described in Table 1. The filament
regulator output supplies power to the filament transformers in the High Voltage Tank
through the filament drive transistors Q3 and Q4.
The regulated filament voltage is scaled down by R8 and applied to U27-5 on the X-ray
Regulator PCB. This feedback loop is intended to regulate the filament regulator output
to within 15%.
The scaled down filament regulator voltage is also applied to U27-3. The output on U27-
1 (FIL B+ SENSE) is then sent to the Technique Processor, via the Analog Interface
PCB, to be monitored by the system software for abnormal filament regulator voltages.
See Regulator Fail error message at the end of this section for more information.