GE AMX-II Service Manual page 65

GENERAL ELECTRIC MEDICAL SYSTEMS ΑΜΧΞΗΧ-ΒΑΥ UNIT
8-3179 SM A0654E
13. To verify that filament voltage and ma regulator is optimum, refer to Illustration 4-1. Adjustments of
3A2R30 and 3A2R 34 is correct if the center scope trace is obtained when the temporarily installed
ma meter reads 100 ma during an exposure. If more or less than 100 ma is obtained with the trace
as shown at the center of Illustration 4-1, readjust 3A2R34, then readjust 3A2R30 to obtain the
center trace. Repeat this procedure until the center trace is obtained when the x-ray tube current
is 100 ma +/-5%. Record in F3382, Test 22 and F3316.
PROBE: Top of 3A2C55
GND: Bottom of 3A2C55
H: 20 ms/div
V: 0.2v/div x 10 (Probe)
TRIG: INT,DC,+,Set Point
Upper Trace: Filament voltage too high and
regulator pulling down or filament voltage normal
but regulator pulling down improperly.
Center Trace: Filament voltage correct and ma
regulator adjusted correctly.
Lower Trace: Filament voltage too low and ma
regulator pulling up cr filament voltage normal
but regulator pulling up improperly.
18775-P10
ILLUSTRATION 4-1
2-5 Test the Timer
The timer was calibrated at the factory and should not require readjustment at installation. This is a
function check to verify operation before proceeding further.
1. Check that the scope horizontal sweep calibration is correct.
a 2. Connect the scope as shown in Illustration 4-2. Make x-ray exposures at 10 mas and 100 mas,
80 kvp.
3 If the trace does not correspond with Illustration 4-2, adjust 3A1R7 to obtain correct interval
timing for the 100 mas selection as shown in the lower waveform of Illustration 4-2.
sb Check the interval timing for the 100 mas exposure. Time should be correct within +/-2%. Record in
F3316.
a
5. Select 80 kVp, 1 mAs, Make another exposure and only if necessary, adjust 3A1R9 for exposure
interval of 10 MS.
6. If the timer adjustment fails to provide proper.exposure timing, check for proper operation of the
control SCR (2CR2) and the turnoff SCR (2CR1).
44