| 摘要 |
PURPOSE:To improve the accuracy and the functional, performance, by detecting an average voltage from an output voltage of a bridge circuit by a control circuit in the proportional comparison system. CONSTITUTION:Four sides constituting the bridge circuit A are provided with resistors R1, R2, R3 and R4 being a distortion detecting element respectively. Output terminals (a), (b) are connected to a control circuit B via a switch E and an amplifier 1. When a load is applied to a load cell, the resistors R1, R2 of the circuit A change according to the load, voltages Va, Vb at the output terminals (a), (b) are changed and outputted to a circuit B for output time t1, t2 controlled with the switch E. The circuit B detects an average voltage Vc, of the Va, Vb. A comparison circuit D outputs each period when the Vc crossing with a waveform of one period of the sawtooth waveform based on the said waveform outputted from an oscillating circuit C. The switch E switches the two output terminals alternately with this output. |
