Planmeca Proline XC, Техническое руководство, Страница: 248 / 258

Chapter I - FUNCTIONAL DESCRIPTION
I-12 Planmeca Proline XC X-ray unit
ELECTRICAL PARTS AND THEIR FUNCTIONS
Technical Manual
2 ELECTRICAL PARTS AND THEIR FUNCTIONS
The electronics of the equipment consists of the tube head, ten printed circuit boards, six
motors, three lights and the cables connecting these parts to each other. These parts are
located in the equipment itself and in following it is explained where they are and what are
their functions.
2.1 Tube head
The tube head is located at the other end of the rotating part. The function of it is to convert
the high frequency power, supplied by the generator circuit board, into X-rays. The high volt-
age transformer and cascade circuit board in the tube head rectify and multiply this power to a
maximum of 80 kV DC to the X-ray tube which in turn generates the radiation. The metal case
gives a radiation-proof hermetically closed housing to the X-ray tube. Because of the high
voltage needed by the tube, the tube head is filled with transformer oil to give successive
insulation. The tube head inner parts cannot be serviced in the field, because the opening of it
needs extra clean environment and after opening the oil must be dried in vacuum, but the
tube head temperature sensor is located in the center of the connector P1 and can be
replaced without removing the tube head.
When the tube head is replaced it must be correctly aligned and the tube type must be given
to the system, after which the system must be allowed to learn the filament characteristics.
2.2 Circuit boards
There are nine circuit boards in the equipment. In the following their locations and functions
are described as well as the actions that should be taken when replacing one. Also the on
board fuse ratings are marked.
CAUTION When connecting or disconnecting cables and/or circuit boards the power must be
switched off and a 10 second time must be allowed to the capacitors to discharge. Oth-
erwise damage can be caused to the circuit boards.
CAUTION To avoid damage caused by static discharge always discharge yourself by touching the
earthed metal frame before touching the electrical parts.
Cascade circuit board (105-10-01)
This circuit board is in the tube head multiplying the high voltage to the X-ray tube. It cannot
be seen or serviced in the field, because the opening of the tube head needs extra clean envi-
ronment, vacuum pumps etc.
Tube power supply (or simply PSU) (105-10-26)
This circuit board is in the horizontal section of the rotating part, nearest to the tube head. It’s
function is to generate the X-ray tube filament power and the high frequency AC power to the
tube head high voltage transformer.
CAUTION Always turn off the mains switch before handling the board because the mains voltage
comes onto this board. Always allow at least two minutes of time to the capacitors to
discharge after the power has been on.