11 TUBE AND HIGH-VOLTAGE CABLE TEST WITH HIGH VOLTAGE
Even if
– the battery test to check a short at the high-voltage cables (chapter 5),
– the visual tube check (chapter 6) and
– the audible tube check (chapters 8 + 10)
did not lead to defective parts at first sight, these might be discovered once high voltage is up again.
Therefore the following test procedure was created to switch exposures just for 1ms before any part of the gen‐
erator might be overloaded from a defective tube or HV cable.
▪ Switch OFF the generator .
▪ Establish the test cable with diode at the backpanel service measuring points:
EZX74 (CTRL_X_C/ = cathode of diode) > open plug
and
EZX77 (X_ACT_S/ = anode of diode) > green plug cover
▪ Establish just one side first (with the 4mm plug) of the test cable with resistor
at the mAs short-circuit plug (either side, short-circuit plug remains in) of the measuring circuit EG100
(if access is not possible loosen screening cap of primary lines.)
▪ Establish oscilloscope connections:
channel 1 = anode EZ130 X4 AV_AN 20kV = 1V 0.5V/div
channel 2 = cathode (also positive) EZ130 X5 AV_CA 20kV = 1V 0.5V/div
ground = EZ130 X6/X32 GNDA
trigger = signal CTRL_X_C/ at EZX74 must be used, negative slope, trigger level 2.5V
(if a third probe is not available use one channel for triggering with CTRL_X_C/ and check anode and cathode side
individually)
time base = 200µs/div, trigger delay -1div
Explanation:
With these hardware modifications and exposure settings the exposure time is only 1ms.
The additional resistor simulates an emission current of 500mA which lets the mAs counter of mA-control terminate
the exposure at 1ms (= 0.5mAs).
Under normal conditions the mAs counter is triggered by the signal X_ACT_S/. As this might be missing due to a
problem in the system the additional diode drives, the kV start command CTRL_X_C/ also at X_ACT_S/ to trigger
the mAs counter and ensures the short exposure. The oscilloscope must be triggered with CRTL_X_C/ for the
same reason to get a display.
▪ Switch ON the generator.
▪ Set one RGDV for the following procedure or create a new RGDV just for the test (ignore other settings in data
set A):
Enable handswitch at generator desk: Yes
Syncmaster present (e.g. grid contact): No
Exposure switch type: Double Step
Installed radiographical controller: none
Release circuit adaptation unit: none
Installed tomo extension: none
Converter test kit OPTIMUS for OPTIMUS 50/65/80 gen‐
erators release 3.x with converters 4512 104 7231x
Conv test Optimus CSIP Level 1 (08.0)
© 2008 Koninklijke Philips Electronics N.V.
ALL RIGHTS RESERVED
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