Planmeca Proline CC, Technical Manual

Page: 194 / 207

Chapter I - FUNCTIONAL DESCRIPTION
I-8 Planmeca Proline CC panoramic x-ray
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 voltage
transformer and cascade circuit board in the tube head rectify and multiply this power to a maxi-
mum 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. Other-
wise 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 environ-
ment, vacuum pumps etc.
Tube power generator (or simply generator) (105-10-02)
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.
When this circuit board is replaced the jumper settings and fuse ratings must be checked to
match the ones of the faulty circuit board. Be sure that the voltage selection is the same than on
the LOW VOLTAGE POWER SUPPLY circuit board.
J1 selects the inverter operation voltage range (110 = 90 V - 130 V; 220 = 190 V - 265 V)
J2 selects the control circuitry operating voltage and must be set accordingly to J1
J3 selects the tube filament voltage range (C = Comet tube; T = Toshiba tube)
F1 is the main fuse (8AT for 190 - 265 V; 15AT for 90 - 130 V)
F2 protects the current inrush limiting resistor R1 and is always rated 1AT
F3 is the mains transformer fuse (250 mAT for 190 - 265 V; 500 mAT for 90 - 130 V)
F4 is the inverter end stage fuse and is always rated 8AFF (Superfast)
F5 is the inverter end stage fuse and is always rated 8AFF (Superfast)
F6 is the control circuitry secondary fuse and is always rated 1AT
F7 is the filament circuitry secondary fuse (3.15 AF for Comet; 4 AF for Toshiba)
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 dis-
charge after the power has been on.