KaVo ORTHOPANTOMOGAPH OP 2D, Service Manual

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46 ORTHOPANTOMOGAPH OP 2D
3. Circuit Boards - L1800
L1800 - Description
The Generator board receives kV and mA reference
signals from L1200 as PWM modulated signal. Based
on the kV-reference value, the Generator board gener-
ates the corresponding high voltage between the cath-
ode and anode of the x-ray tube. Based on milliampere
reference value, the generator board generates pre-
heat current (to warm up the fi lament before x-rays are
switched on) and fi lament current (during exposure).
The Generator board receives kV and mA feedback
signals from the tubehead. The kV and mA feedback
signals are used to monitor and adjust the generated
values. The P1910 PFC board supplies the L1800
generator board with 380VDC, 27.5VDC and 20VDC
voltages. The generator board then produces its own
supply voltages, for example the fi lament output voltage
for the tubehead, utilizing these input voltages.