US4696359A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic weighing apparatus
Assignee: NATIONAL TRANSDUCER CORP
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Filing: 1986-08-22
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Granted: 1987-09-29
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Expires: 2006-08-22
Abstract
Abstract An electronic weighing apparatus providing accurate weight using a low level power supply. A force responsive strain gauge having a high impedance, provides an electrical output to a sample and hold circuit. The signal from the strain gauge is conditioned by a sequencing circuit which turns the strain gauge and sample and hold circuit on and off at a rate providing a very low duty cycle to keep power consumption to a low level. Power is supplied by a photo-voltaic panel built into the electronic weighing apparatus responsive in light levels as low as 50 lux.
Inventors
- 👤 Albert W. Glibbery
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:10
CPC Classifications
G; G01; G01G; G01G23/00; G01G23/18; G01G23/36; G01G23/37; G01G19/00; G01G19/14; G01G19/18; G01G23/007; G01G23/14; G01G23/16; G01G23/163; G01G3/00; G01G3/12; G01G3/14; G01G3/142; G01G3/147
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
108 words
A weighing apparatus comprising: force responsive strain gauge means providing an electrical output; said force responsive strain gauge means having a high impedance; sample and hold circuit means receiving the output from said force responsive transducer means for sampling and holding said output; sequencing means for sequentially turning said force responsive strain guage means and said sample and hold means on and off; digital processing means for processing the output of said sample and hold means; display means for displaying the output of said digital processing means; and low voltage power supply means supplying power to said force responsive transducer and to said sample and hold circuit means.
Claim 2
Dependent Claim
108 words
A weighing apparatus comprising: force responsive strain gauge means providing an electrical output; said force responsive strain gauge means having a high impedance; sample and hold circuit means receiving the output from said force responsive transducer means for sampling and holding said output; sequencing means for sequentially turning said force responsive strain guage means and said sample and hold means on and off; digital processing means for processing the output of said sample and hold means; display means for displaying the output of said digital processing means; and low voltage power supply means supplying power to said force responsive transducer and to said sample and hold circuit means.
Claim 3
Dependent Claim
18 words
Apparatus according to claim 1 wherein said high impedance force responsive transducer means is a high impedance bridge.
Claim 4
Dependent Claim
22 words
The apparatus according to claim 2 wherein said high impedance bridge has an impedance in the range of 4000 to 6000 ohms.
Claim 5
Dependent Claim
23 words
The apparatus according to claim 2 in which the duty cycle in said sequencing means is in the range of 1% to 5%.
Claim 6
Dependent Claim
18 words
The apparatus according to claim 2 in which the duty cycle of said sequencing means is approximately 1%.
Claim 7
Dependent Claim
27 words
The apparatus according to claim 1 in which said low level power supply means is a light responsive power supply means producing a low level power output.
Claim 8
Dependent Claim
18 words
The apparatus according to claim 6 with said light responsive power supply means is a photo-voltaic panel means.
Claim 9
Dependent Claim
31 words
The apparatus according to claim 1 in which said sequencing means sequences said sample and hold means on and off at a duty cycle in the range of 1% to 10%.
Claim 10
Dependent Claim
55 words
The apparatus according to claim 1 in which said digital processing means includes; a summing circuit receiving output of said sample and hold means; analog to digital converting means receiving the output of said summing circuit; and display logic means receiving the output of said analog to digital converting means to drive said display means.
Claim 11
Dependent Claim
45 words
The apparatus according to claim 9 including zero-tracking means; said zero-tracking means continuously sampling small amounts of contamination weight on a weight container on said scale; the output of said zero-tracking circuit being connected to said summing circuit to re-adjust the display to zero periodically.
Claim 12
Dependent Claim
59 words
The apparatus according to claim 9 including; a dual range switch cavity; said dual range switching circuit receiving the output of said sample and hold circuit and providing an output to said summing circuit to switch said summing circuit to or from a high resolution to a low resolution when the weight on the scale exceeds a predetermined amount.
Claim 13
Dependent Claim
33 words
The apparatus according to claim 11 in which said dual range switching circuit switches the output of said display to or from a two decimal point resolution to a single decimal point resolution.
Claim 14
Dependent Claim
18 words
The apparatus according to claim 9 including a tare circuit for adding the tare weight of a container.
Claim 15
Dependent Claim
23 words
The apparatus according to claim 13 in which said tare circuit comprises; switch means for inserting up or down counts to the display.
Claim 16
Dependent Claim
40 words
The apparatus according to claim 14 in which said switch means comprises a pair of pushbutton switches; an up/down counter activated by said pushbutton switches; said pushbutton switches being connected to reset said tare circuit to zero when activated simultaneously.
References Cited (Backward Citations)
US4531600A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-09-28 | 1991-03-30 | 1991-09-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-09-28 | 1995-03-30 | 1995-09-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-09-28 | 1999-03-30 | 1999-09-29 | $7700.00 | Window Closed / Lapsed |