Service manual

- alsa apparecchi medicali s.r.l. -
Pag. 10
PWRFM SIGNAL, CALIBRATION OF THE OUTPUT OFFSET
1)Connect the oscilloscope to TP “P” on Power reader board (2). Set function “monopolar PC” and code 10.
Without activating the device, calibrate the R31 pot on the same board to obtain a voltage of 124 mV .
2)Connect then the probe to TP “Q” (same setting) and, without activating the device, calibrate the R43 pot
to obtain a voltage of 100 mV.
IRFMB SIGNAL, CALIBRATION OF THE OUTPUT OFFSET
1)Connect the oscilloscope to TP “P” on Power reader board (2). Set function “monopolar PC” and code 10.
Without activating the device, calibrate the R75 pot on the same board to obtain a voltage of 133 mV .
2)Connect the oscilloscope to TP “S” (same setting) and, without activating the device, calibrate the R81 pot
to obtain a voltage of 100mV.
Once all these settings have been completed, check the output offsets again with the oscilloscope
connected to TP “N” on Power reader board setting (function “monopolar PC” and codes as detailed
in the following reference table)
Reference table: Use reference values (tol ±5%) if the power reading section needs to be adjusted.
The values for the various test points depend on the H.F. output current specified.
Settino
value
I OUT
(mA)
TP “N” TP “N
1
” TP “N
2
” TP “P” TP “Q” TP “R” TP “S”
14
100 0.136 0.182 0.050 0.664 0.564 1.220 0.925
2A
200 0.269 0.358 0.174 1.290 1.090 1.700 1.290
3E
300 0.400 0.535 0.382 1.930 1.630 2.080 1.580
53
400 0.541 0.718 0.685 2.590 2.190 2.410 1.820
67
500 0.670 0.890 1.050 3.240 2.720 2.690 2.040
76
600 0.803 1.018 1.390 3.910 3.260 2.950 2.230
90
700 0.940 1.248 2.060 4.540 3.820 3.190 2.410
A5
800 1.070 1.428 2.700 5.210 4.370 3.410 2.580
BA
900 1.200 1.620 3.400 5.86 4.910 3.620 2.750
D2
1000 1.350 1.793 4.190 6.540 5.400 3.810 2.890
To modify the value on TP “N” on Power reader board (2), set function “monopolar PC”, code as above
detailed, activate the unit and adjust the R5 pot of the Power reader board (1). Doing this calibration also the
value on TP “N
2
” on Power reader board (2) should be that indicated in the reference table.
The value of TP “N
1
” on the same board can be calibrated, if necessary, adjusting the R6 pot on the Power
reader board (2).
When you have controlled the voltage on TP “N
1
” of Power reader board (2), check the corresponding value
on TP “R” of the same board and, if necessary, calibrate R75 on the Power reader board (2) to obtain on TP
“S” of the same board the values of the reference table.
The value on TP “Q” of Power reader board (2) can be calibrated, if necessary, adjusting the R43 pot on the
Power reader board (2).
Additional check:
1)Connect the monopolar output to a load of 400 ohm
2)Select function “monopolar PC”
3)Activate the unit and check the values according to the following table (tol ±10%). For every code selected
is specified the output current, the voltage PWRFM - pin 1 of J3 connector on Power reader board (2), the
voltage IRFMB - pin 3 of the same connector.
Display Iout (mA) PWRFM (V) IRFMB (V)
A9 786.33 4.30 2.57
93 689.67 3.78 2.46
6A 499.67 2.71 2.06
54 395.00 2.15 1.83
3F 297.00 1.61 1.59
13 94.90 0.53 0.89
CONTROL OF SIGNALS FOR THE CORRECT OUTPUT POWER
OUTPUT SIGNAL, CONTROL OF THE AVERAGE MODULATION VALUE