| 摘要 |
PURPOSE:To simplify the adjustments of the weight sensor and a sensor circuit remarkably by a method wherein a memory unit, memorizing the output of the weight sensor under a condition that it is not weighed, is provided to change the amplifying degree of the sensor circuit in accordance with a difference between the content of the memory unit and the output of the weight sensor under a condition that a reference weight is weighed thereon. CONSTITUTION:A micro-computer 20 monitors the change of output of an amplifying degree switching circuit 60 by the output of an A/D converter 70 and compares the output with a reference weight output V, which is memorized previously, when the output of the amplifying degree switching circuit 60 is changed by putting the reference weight on a shelf board 1. Then, the micro-computer 20 puts ON signals F, G, H, I selectively and switches the amplifying degree of a positive phase amplifier 65 in the amplifying degree switching circuit 60 so that said output becomes the reference weight output V. That means the amplifying degree is switched indirectly. Thus, the adjustments of the weight sensor 3 and the sensor circuit 4 are finished. The data of adjusting process are memorized into the nonvolatile memory of the micro-computer 20 or ROM, for example, and the after processing work for adjustment becomes unnecessary. |
