| 摘要 |
PURPOSE:To perform weighing accurately by amplifying the outputs of plural load cells with each of plural buffer amplifiers, adding the same with an adder and connecting an analog switch via a capacitor between the output terminals thereof. CONSTITUTION:Load cells 1, 2, 3, 4 are connected respectively on one side to buffer amplifiers 7, 8, 9, 10 and on the other side to the ground. The amplifiers 7, 8, 9, 10 are connected respecitively to an adder 11. The adder 11 is connected with an operational amplifier 16 as an output terminal and is connected with an analog switch 20 between the same and the ground via a resistance 18 and a capacitor 19 in series. An operational amplifier 21 connected to the point of connection between the capacitor 19 and the switch 20 as its input inputs the output thereof to the input terminal of an A/D converter 33 via a low-pass filter 42 so that the output is converted to count data. An arithmetic circuit 43 is operated by a controller 44 to convert the data to the weight data in gram unit and the weight data is displayed on a display device 45. |
