Service manual

- alsa apparecchi medicali s.r.l. -

Pag. 9

(TP “L”; TP “M”)

Ch1

Ch2

1us

4us

1.4us

Ch1 Ch2

The width of the "Ch2" pulse must be 4 ms and can be calibrated using the R35 pot on the R.F. power board.

The delay between the two pulses must be equal to 1.4 ms and can be calibrated using the R31 pot of the

same board.

Once this board is calibrated, disconnect the “wiring for assistance” and re-position the board inside the

device re-connecting both the standard wiring and the J5 connector.

CALIBRATION OF “POWER READING SECTION”

To start the following tests perform the selection detailed on the table below

Setting Memory Monopolar Cut Display Monopolar Coag. Display

M II

The correct running of the whole device depends on the calibration of this section, as the microcontroller

section is mainly based on signals coming from this section to carry out many of the controls and

adjustments needed to grant the efficiency of the unit. It is therefore necessary to perform this calibration

with maximum care.

Before continuing the calibration, turn the R4 pot on the R.F. main board completely anti-

clockwise in order to release the output current limitation. This current must be limited again

before performing the test “calibration of the limitation of the maximum output current” in order

to avoid damages connecting the output to a load lower than 50 V.

1)Connect the monopolar output to a 400 Ω load and connect the current probe to check the output wave

form and current. Connect the voltage probe to TP “N” on the Power reader board (2, set function

“monopolar PC” and code "56".

2)Activating the unit check the output current, should be equal to 400 mA (the starting code "56" is only a

reference; if necessary adjust until 400 mA are obtained.

Using the R4 pot of the Power reader board (1), calibrate the wave form read by the voltage probe so that it

is without distortions and as equal as possible to the current wave form.

(I out; TP “N”)

Ch1

Ch2

ANALOG MULTIPLIER, CALIBRATION OF THE OFFSET OF THE "X" INPUTS

1)Connect the R4-R5 resistors on the Power reader board (2) to ground on the opposite side of U2 and

connect the probe of the oscilloscope to TP “O” on the same board.

2)Set function “monopolar PC” and code "10", activate the device and adjust the R3 pot on that board to

obtain the minimum amplitude of signal.

3)Disconnect from ground the R4-R5 resistors.

ANALOG MULTIPLIER, CALIBRATION OF THE OFFSET OF THE "Y" INPUTS

Repeat for the R7-R8 resistors (adjusting pot R6) on the same board the procedure above detailed about

R4-R5 resistors.