| 摘要 |
PURPOSE:To obtain a proper holding force controlling system by using a proportional integral filter and offset correcting circuit for reproducing the force (static and dynamic forces) impressed to a piezoelectric element from an output voltage signal of said element. CONSTITUTION:A piezoelectric element 1, an input amplifier 4, a microprocessor 21 and an A/D convertor 20 for converting an analog output voltage of the input amplifier 4 to a digital code are provided. The analog voltage is digitized (quantized) by the A/D convertor and the offset voltage is corrected by the microprocessor 21 and a proportional integral filtering is performed. |
