Application Note Number 9
Use caution when testing the GE "Light Speedtm"
CT scanner
Please be very careful when testing the GE Light Speed CT scanner. It uses
the anode high voltage cable to send stator power to the x-ray tube.
- The Dynalyzer, HV-1 Voltage Divider, and Nuclear Associates 07-476
voltage divider all have the three wires in the anode of the voltage divider
shorted together.
- This shorting will cause damage to the stator supply of your scanner.
- GE has made this change because the rotor of the x-ray tube and stator are
closely coupled. This permits the very large anode to rev up to speed
quickly, so as to reduce stress on the vacuum bearings.
- At this point, it is possible to measure the voltage applied to the x-ray
tube by using either a GE bleeder, which is not frequency compensated for
pulses, or the GiCi PM2000 voltage divider which is frequency compensated.
Both of these voltage dividers have all three wires of the anode separate,
and routed straight thru. The high voltage measurement is made from
the Common lead to ground.
- We can modify your HV-1 or Nuclear Associates divider for three through
wires on anode for $400 including recalibration.