摘要 |
An energy efficient scale using a load cell for weight detection and a power supply for powering the load cell at one or another of three different current levels. The highest current level provides accurate weight indication. The intermediate current level provides only a signal indicating the presence of a package on the scale. The lowest current level is sufficient only for keeping the load cell electrically centered. If a package is placed on the scale while the load cell is receiving current at the intermediate level, then a resulting package detection signal causes the scale to switch to full operating current.
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