Siemens MOBILETT Plus Manual page 19

Power-up sequences
Board D8 is supplied with the line voltage via the mains cable and main switch "S11".
Board D8 furnishes nine different DC voltages, which are fed to the autonomous voltage
stabilization circuits on boards D1, D3, D4, D7 and D13.
There they are transformed into the required supply voltages and displayed via LEDs.
On board D1 the red "reset" LED lights up briefly, followed by the initialization and
self-test.
During this phase, approx. 1 s, the display on the Control and display panel is not
lit up.
However, on board D3 the red "start up" LED is illuminated. This is located at the right,
next to the kV display.
Following this:
•
the filament circuit on board D4 is activated and the preheating of the filament spiral in
the single tank is turned on,
•
a braking procedure is initiated for the rotating anode in the single tank,
•
the exposure-parameter display on board D3 is activated,
Preferentially, after the initial message "HEJ" "HEJ", the display will show whatever
exposure parameter displayed before the last switch-off of the unit,
•
if the start voltage in the capacitor bank, M1, is <10 V, the capacitor bank will be charged
to 150 V during the first charging phase.
After a brief pause of about 5 s, during which the leakage current from the capacitor bank
is calculated from the discharge characteristic of the capacitor bank, the second
charging phase takes place.
•
the final voltage value of the capacitor bank, M1, depends on the exposure parameters
displayed.
Siemens-Elema AB
Solna, Sweden
The final values are:
300 V with a tube voltage display of < 45 kV
with a tube voltage display of " 45 kV and < 50 kV
325 V
with a tube voltage display of " 50 kV
350 V
Register 6 SPR8-215.850.02
Rev. 01 01.02
6
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