| 摘要 |
PURPOSE:To perform weighing at a high speed without generating a response delay in a filter, by a method wherein an active filter is set to a voltage setting mode at the time of non-weighing and the article wt. voltage corresponding to a reference value is inputted to preparatorily charge a capacitor and the active filter is changed over at the time of weighing to input a wt. signal. CONSTITUTION:A change-over means E is constituted of a switch S1 and an amplifier P1 and an active filter F has mode change-over switches S2-S7, cascade connection LPFF1-F3, amplifiers P2-P4, resistors r2, r4; r6, r8; r10, r12 connected to the non-reversal input terminals of said amplifiers in series, capacitors C1-C4; C2, C5; C3, C8 forming integration circuits and charge resistors, r1, r3; r5, r7; r9, r11. When a voltage mode is set, Vref is inputted to the non- reversal input terminal of the amplifier P1 through S1 by the control of a computer and the capacitors C1-C6 are charged with the added values of the offset voltages of the amplifiers and reference voltage to form outputs Vout. Therefore, when S2-S7 are changed over to set a filter mode, offset voltages are removed and response delay is improved and rapid signal processing can be performed. The change-over of S1-S7 are entirely performed by the control of the computer. |
