PURPOSE: To measure the position of a magnetic armature and/or the magnetic value of a coil from an arbitrary spatial distance via an already installed control line by providing a sensor independently of a magnet and/or the coil.
CONSTITUTION: An armature 7 and a coil 8 are provided at an electromagnet 3 in an equipment 6 and current is supplied to the coil 8 via a power supply line 2 from a starting device 9. A capacitor 1 is connected to an arbitrary location of the supply line 2 in parallel and the capacity is larger than that of the supply line 2. Then, a voltage with a specific frequency is supplied from an oscillator 12 to a sensor 4 and the output terminal of the sensor 4 is connected to the supply line 2. A response function is achieved by the resonance frequency of a parallel resonance circuit formed by the inductance of the coil 8 and the capacity of the capacitor 1 and the position of the armature 7 can be detected from this function. A processing device 5 is used for the measurement and is connected to the supply line 2 via a coupling reduction circuit 13 and the measuring position of the armature 7 is displayed on a display 14 at the later stage of the device 5.
PEETAA BUINTAAHARUTAA
GIYUNTAA FUEIAA
