Ion Chamber Amplifier Comparator
The Ion Chamber Amplifier indicates the neutron flux levels in a CANDU nuclear reactor. If it detects certain low or high conditions, it trips the corresponding alarm circuitry. The amplifier system consists of four distinct sections:
Logarithmic Amplifier
This section converts the input ion chamber current into a voltage output proportional to the logarithm of the ion chamber current. The output feeds two comparators. One comparator checks the low limit and the other checks the high limit. Both comparator outputs feed alarm circuits.
High Voltage Supply
The High Voltage power supply section provides the power supply polarizing voltage to the ion chamber high voltage electrodes.
Linear Amplifier
The linear Amplifier section provides more accuracy and higher resolution in the top two power decades of operation. The output feeds the linear comparator which activates the high linear alarm.
Logarithmic Rate of Change Amplifier
This section is an active differentiating amplifier that receives its input from the log amplifier and produces an output voltage that is proportional to the rate of change of the logarithmic signal. The output feeds the log-rate comparator which trips the alarm circuit when the log-rate is high.
