Dual-range analog-to-digital convertor
US4706767A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 26, 1986 |
| Grant date | Nov 17, 1987 |
| Priority date | — |
| Expiry date | Nov 26, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01G21/00
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Method and apparatus for the improved operation of an electronic computing scale provides significantly increased resolution in a first weight sub-range (0-12 pounds in the illustrative embodiment). A coarser resolution is provided in a second weight sub-range (11-100 pounds). The raw load cell voltage is communicated along first and second branches, and subjected to a different transformation in each branch to produce first and second transformed voltages. In the first branch, raw voltages corresponding to weights in the low sub-range are mapped onto a desired sub-range of voltages. In the second branch, raw voltages corresponding to weights in the high sub-range are mapped onto a second sub-range of voltages. Depending on the weight on the scale, one or the other of the transformed voltages is applied to the ADC input terminal, and the digital output is scaled accordingly. The circuitry includes a range flag and logic circuitry for sensing the digital ADC output, and controlling the range flag. When the range flag is in a first state (signifying that the low weight sub-range is selected) and the ADC output signifies a weight above the low sub-range, the range flag is set to a sec…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.