Siemens MOBILETT Plus HP - Tests and Measurements in the High Voltage Circuit

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Siemens AG SPR8-220.061.03 Page 1 of 12 MOBILETT Plus HP
Medical Solutions Rev. 03 09.03 CS PS 24
HT and single tank error diagnosis 6
Tests and measurements in the high voltage circuit 6
• Connect the oscilloscope measurement cables to measuring points HTPOS and HTNEG
or HT on D1.
• Adjust the trigger point to the falling edge of the high voltage curve and set the time to
20 - 50 ms/Div.
• If the high voltage cannot be displayed, check the tube current at measurement point
MAPOS on D1. Check the inverter current with an external current transformer.
• Measure HTPOS and HTNEG on D1. Record the fall times (90 - 10% of HT), high
voltage levels and whether the exposure was interrupted prematurely. Compare with
Fig. 2 "HT and inverter current, inverter and single tank normal" .
• Measure the inverter current using an external current transformer and the HT. Compare
with Fig. 1 "HTPEAK and inverter current, inverter and single tank normal" .
• In case of an error, compare the oscillogram with Fig. 1 "HTPEAK and inverter current,
inverter and single tank normal" .
The inverter current is always measured using a separate current
transformer between the inverter and single tank.
NOTE