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Rotating anode starter
MAMMOMAT Balance
SPB7-115.840.01 Page 23 of 62
Siemens AG
Troubleshooting Guide
Rev.02 10.04
Medical Solutions
Rotating anode starter
Calibration of protection circuit
•
General information
Protection circuit calibration is necessary if PCB, shift capacitors or tube is/are replaced.
Calibration is also necessary if unit is operated at 60hz line frequency.
For circuit calibration select: DEMO mode by means of DIP 3 SW1 PCB 01-170 = ON, Manual mode,
200mAs or more, remove table.
Only if necessary, disable protection circuit shorting JP4.
DEMO mode is selected to avoid x-ray emission and tube anode loading.
High mAs value is selected to have stable voltage readings at Test points TP1, TP2, TP3, TP4.
Use only isolated tools
Anode starter PCB 92-074 has two independent protection circuits for direct and shifted phase.
Voltage at TP1 represents Direct phase current and voltage at TP3 represents minimum reference
level, normal operating conditions is with VTP1 > VTP3.
Voltage at TP2 represents Shifted phase current and voltage at TP4 represents minimum reference
level, normal operating conditions is with VTP2 > VTP4.
Voltage at TP1 and TP2 is present only during tube rotation.
Voltage at TP3 and TP4 is fix and can be adjusted by means of RV1 and RV2 .
All voltages are measured with respect to GND Test point of PCB 92-074
during tube running
not
boost.
CAUTION