| 摘要 |
<p>PURPOSE:To eliminate the scale correction for each switching of the scale width and to facilitate easy handling of a multi-range controller, by changing the amplification characteristics of an input signal according to the scale of the controller and correcting the input signal based on the A/D conversion output value. CONSTITUTION:A control part 3 checks the position of a switch 9 to decide a scale where a controller starts its actuation after application of the power supply of the controller. Then the part 3 controls a switch 7 to control the gain of an analog amplifier 1. The output of an A/D converter 2 is referred to as D0, DS and D1 when an input/output changeover switch 6 is set at the lowest, medium and highest levels respectively. Therefore an input signal Ei is equal to (D1- D0)/(DS-D0).Es. Thus the offset voltage and the gain of the amplifier 1 receive no effect at all.</p> |
