| 摘要 |
A method for detecting low battery voltage in a hand-held scanner capable of reading the likes of a bar code measures the speed of the motor driving the scanning element and compares it to stored values. The stored values represent motor speeds directly corresponding to maximum and minimum battery voltages. The stored values can be introduced to the scanner for example, at the factory. If the motor speed is found to be lower than the speed corresponding to the minimum acceptable battery voltage, user understandable message is produced, which necessitates either battery re-charging or replacement.
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