| 摘要 |
The present invention is a multiple range electronic weigh scale which employs a single load cell and selectable amplifier gain. A more sensitive range would employ a higher gain amplification than a less sensitive range. In accordance with the preferred embodiment, the amplified load cell signal is applied to an analog to digital converter and the digital output is applied to a microprocessor. The microprocessor enables selection between the weight ranges based upon the relationship of the digital output to upper and lower limit values. The microprocessor also generates the output weight signal for display based upon the product of the digital output and the selected gain. In a further embodiment the microprocessor generates a digital offset signal which is applied to the inverting input of a differential amplified via a digital to analog converter. This permits the starting point of the most sensitive range of the electronic weigh scale to be adjusted to any desired point in the higher range.
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