| 摘要 |
PURPOSE:To detect a moving object without changing the phase of an AC voltage induced by means of two loop coils by arranging two loop coils in series in the direction of movement and processing a voltage induced on these loop coils. CONSTITUTION:The lengths of two loop coils 2a, 2b provided on a moving object are reduced to half the crossing space between two electric wries 1a, 1b stretched in parallel where an AC current is run respectively. Two loop coils 2a, 2b are provided in series in the direction of movement. Suppose voltages induced on two loop coils 2a, 2b are Va and Vb respectively. The position of a moving object is detected by a combination of a signal to indicate whether Va and Vb represent an in-phase or antiphase and a signal obtained through comparison of the value of a signal expressed by (Va/Vb)-(Vb-va) and a reference value set beforehand according to the position of a moving object. |
