Service manual

GE MEDICAL SYSTEMS
D
IRECTION 2300749-100, REVISION 2LOGIQ
TM
3 SERVICE MANUAL
Chapter 5 5-13
5-5-4 TX Power/HV Power Supply
Figure 5-10 HV Unit Block Diagram
5-5-4-1 Overview
AC110V is supplied to the HV unit via AC Box > Transformer > ACI PCB. This is applied to the PFC,
inside the HV unit. The PFC convert AC100V to DC400V, and DC voltage is applied to DC/DC, then to
HVH, HVL, and SHV using dropper. They convert DC voltage to proper voltage to be outputted.
5-5-4-2 Specifications
DC Output Capacity:
• HVH: +/- 0V to +/- 60V variable, Max. 110W, Max. 2A
• HVL: +/-0V to +/- 30V variable, Max, 70W, 1A
• +SHV: +80V +/- 5%, 80mA
• -SHV: -80V +/- 5%, 80mA
5-5-4-3 Output Signal to FEC
The following signals are sent to FEC via BACKPLANE board.
• OV (Over Voltage), OC (Over Current) of each power source: HV tests in itself. The result transmits
the FEC via BACKPLANE ASSY.
5-5-4-4 Input Signal from FEC
The following signals are sent to HV unit via FEC > BACKPLANE board.
• +5V, +/- 12V, HV STOP: These signals are sent to PFC to control DC voltage output of HVH, HVL,
and -SHV. Normally HVSTOP is ON
• HVH Ref, HVL Ref: These are the digital signals (8 bits) sent to the DAC of HVH or HVL from FEC.
Consequently, The DC Voltage (0 - 60V) is outputted from HV unit.
AC_IN
PFC
PWM1
(HVH)
PWM2
(HVL)
PWM3
(SVH)
DROPPER 1
DROPPER 1
DROPPER 2
DROPPER 2
DROPPER 3
DROPPER 3
+HVH
(0~60V)
- HVH
(0~ - 60V)
+HVL
(0~30V)
- HVL
(0~ - 30V)
+SVH
(80V)
- SVH
(80V)