GE_OEC_9600_C-Arms

4 kV Generation
KV SENSE
Detects the actual kV generated by the kV drive circuit. The actual kV generated in the
High Voltage Tank is detected by a capacitive sense circuit in the Tank. This KV
SENSE signal is a sine wave with a 1V/10 kV ratio which is applied to the X-ray
Regulator TP10 through buffer U16-3 and U16-1.
The positive peak of the KV SENSE sine wave is then measured by the positive peak
detector made up of U18, U22 and U26. The output of this peak detector can be
measured on TP12 which has a scale factor of +1 VDC /10 kV. This represents the kV
applied to the anode of the X-ray tube.
The negative portion of the KV SENSE sine wave is inverted by inverting buffer U16-6
and U16-7 and measured by the negative peak detector made up of U18, U25 and U26.
The output of this peak detector can be measured on TP13 which also has a scale factor
of +1 VDC /10 kV. This represents the kV applied to the cathode of the X-ray tube.
The two outputs from the peak detectors are then combined through buffer U20-3
and U20-1. This output can be measured on TP9 which has a scale factor of
+1 VDC /20 kV and is called KVP MEASURED. This dc voltage represents the actual
kV generated by the High Voltage Tank which is applied across the cathode and anode
of the X-ray tube. This actual kV sensed signal (KVP MEASURED) is then applied to
the R25 and error amp U23-2 summing point to be compared with the desired kV (KVP
CONTROL) from the Analog Interface D/A U31. It is also sent to the Technique
Processor via the Analog Interface A/D Mux U3 to be monitored by software for various
error conditions.