| 摘要 |
PURPOSE:To measure with high accuracy by a titled apparatus, by setting again reference voltage, when the differential amplifier output between analog input voltage to be measured and the reference voltage exceeds the prescribed range. CONSTITUTION:An output V0 of a differential amplifier 6 which is amplified by the difference between voltage V1 to be measured that is resistance-divided by a fixed resistance 3 and a weight sensor 4, and reference voltage V2, is converted into weight by a microcomputer 5 in which an A/D converter is built in. In the case, when the output V0 exceeds the range of input voltage of the A/D converter, a D/A converter 7 is controlled by an output of the microcomputer 5, and the reference voltage V2 of the amplifier 6 is set again at a proper value. As a result, even when a change of input voltage due to temp. drift, etc. occurs, exact measurement is performed. |
