Levex Corporation

Naomasa Oshie

Seiji Toda

Eiichi Hirai

Masayuki Miki

A position sensor is provided comprising a coil () and an electric conductor () or magnetic () both arranged so that the size of their overlapping area (p) is varied as the position of an object to be examined changes, a resistor (), a capacitor (), a comparator () of an inverse output type, and a timing circuit () arranged for uniformly restraining the period (T) of a continuous oscillating motion, herein a displacement of the object to be examined is detected as a change in the time duration (t) which extends from the leading end of the period (T) to a time when the output of the comparator () is turned to a high level as timed with substantially the trailing end of the period (T). The resistance of the resistor () is determined so that a change in the time duration (t) remains minimum when the resistance of the resistor () is varied and when the temperature is at a predetermined degree. As the result, the linearity of the output can be improved over variation of both the temperature and the position.

Position sensor

While a high-frequency pulse is introduced at one end of a parallel conductor which is simulated as in an impedance equivalent state, an impedance mismatch generator is mounted to an intermediate region of the parallel conductor. As the impedance mismatch generator has produced a reflected wave of the pulse, a duration before the reflected wave is received at the one end is measured and multiplied by the propagation speed of voltage to calculate the distance from the pulse introducing point at the one end of the parallel conductor to the impedance mismatch generator.

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Moriyama, Japan

Naomasa Oshie