| 摘要 |
PURPOSE:To facilitate initial adjustment and to hold the linearity of bridge voltage and strain, by setting off offset voltage on the basis of offset calibration value without using an offset control resistor. CONSTITUTION:The bridge output voltage V0 of each of bridge circuits 6 is applied to a multiplexer 10 through an amplifier 8 and a low-pass filter 9 and the multiplexer 10 successively outputs the signal from each of the bridge circuits 6 to an adder 11 in a time sharing manner. At this time, a microprocessor 12 writes the offset calibration value of each of the bridge circuits 6 in a D/A converter 13 in a time sharing manner simultaneously with the change-over of the channel of the multiplexer 10. The output of the D/A converter 13 is applied to the adder 11 and the adder 11 sets off the offset voltage of each of the bridge circuits 6 on the basis of the corresponding offset calibration value to correct bridge output.
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