| 摘要 |
PURPOSE:To offer an inexpensive vibrometer with the same characteristics as those of a differential transformers that can be used when the dontrolling current is either AC or DC current by a method wherein signals sent from two of the Hall elements are differentially processed. CONSTITUTION:21-a, 21-b are a pair of Hall elements arranged in such a way that space relative to a permanent magnet 22 has been made differentially changeable. The numeral 3 refers to a spring supporting the permanent magnet 22 so that the magnet is allowed to move in the limited direction and the spring together with the permanent magnet 22 constitutes a pendulum. Then a controlling current i is sent to the Hall elements 21-a, 21-b. The strength Ha, Hb of the magnetic fields added to the Hall elements in proportion to the changing amount X of the positions of the Hall elements relative to the permanent magnet 22 because of the movement of the pendulum differentially changes, causing the output voltages Va, Vb of the Hall elements each to change. Va, Vb are corrected to the extent of the sensitivity deviation of the Hall elements in a summing amplifier 42, before being added and amplified. The output Vo of the summing amplifier 42, when the controlling current i is made constant using a current controller 41, becomes proportionate to the changing amount X of the positions of the elements 21-a, 21-b. |
