摘要 |
A velocity transducer or Velomitor(R) that can output electrical signals relating to vibration, despite the transducer being exposed to low levels of gamma-radiation, is disclosed. A DC feedback circuit, which sets up the input stage bias point, keeps the output bias voltage within a usable voltage range as the transducer is exposed to the gamma-radiation. An additional JFET transistor, configured as a current source, helps the DC feedback circuit compensate for increases in the offset voltage of the JFET amplifier. The value of a resistor controlling the gate current of the JFET amplifier is also reduced, such that when the leakage current increases, the offset voltage is reduced.
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