PURPOSE: To detect the displacement utilizing changes in inductance of coils by a method wherein a plurality of coils are wound around a bobbin with a space therebetween and a barlike core moving in accordance with the displacement is inserted into the bobbin.
CONSTITUTION: Coils 2 and 3 are separately wound around the outer periphery of a bobbin 1 with a certain space between the coils. A barlike core 4 is enable to be inserted into the bobbin 1 and includes a bar 5 for adjusting its stroke secured at one end of the core. With this arrangement, when AC voltage with a constant amplitude form an AC power supply source 6 is applied across both terminals (a) and (c), there occurs across both terminals (a) and (b) or both terminals (b) and (c) output voltage which is almost linearly varied in accordance with a displacement amount of the core 4. A length of the barlike core 4 is set to be equal to or slightly greater than the sum of winding widths of the respective coils 2, 3 and a space between the coils 2 and 3.
ADACHI TETSUO
ITOU TOSHIKI
