Apparatus for precise detection of blade passing times in a steam turbine

摘要

An apparatus for detecting blade passing times includes a sensor for producing an input signal each time a blade passes the sensor. A zero crossing detector produces an output signal each time the input signal crosses a reference axis. A phase shifter shifts the phase of the input signal to produce a gating signal coinciding with the expected arrival time of the blade at the sensor. A gating device is responsive to the gating signal for conducting output signals which occur during the expected arrival time of the blade at the sensor.