Patent ID: 7739058

Claim:
A system comprising: a condition-monitoring device provided with an electromagnetic actuator including a stationary core, a moving core configured to be movable with respect to the stationary core, magnet coils energized by a drive power-supply, for moving the moving core, and a permanent magnet disposed around the moving core, said the condition-monitoring device for monitoring conditions of the electromagnetic actuator comprising: a current measurement means for measuring a current flowing through the magnet coils; magnetic-flux measurement means for measuring magnetic flux inside the stationary core; a calculation means for generating a calculated waveform by performing a calculation using a current waveform representing a time variation of an output signal from the current measurement means and a magnetic-flux waveform representing a time variation of an output signal from the magnetic-flux measurement means; and a condition determination means, by finding a distinctive point on the calculated waveform, for determining conditions of the electromagnetic actuator, based on information on the distinctive point.