| 摘要 |
The invention relates to a seismic sensor unit (4) for an emergency shutdown system (2) of a nuclear power plant, comprising
€¢ at least one accelerometer (6) for at least one axis,
€¢ a trigger module (8) which processes a signal derived from a measured signal of said accelerometer (6) and generates an output signal from which a trip signal is derived. It is an objective of the present invention to provide a reliable, robust, and non-complex seismic sensor unit (4) of such a type. The proposed solution according to the invention is characterized in that said trigger module (8) comprises an analog peak-hold-circuit (18) processing an input signal (X) and generating an output signal (Y) with the following properties:
€¢ if the input signal (X) is rising and the level of the output signal (Y) is below the level of the input signal (X), the output signal (Y) increases almost instantly with the input signal (X),
€¢ if the level of the input signal (X) is below the level of the output signal (Y), the output signal (Y) essentially keeps the current level unless a reset condition is reached. |
