Proximity selectro with integral magnet, pole-piece plate and pair of magnetic transducers
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United States of America Patent
Stats
-
Aug 22, 1989
Grant Date -
N/A
app pub date -
Mar 18, 1987
filing date -
Mar 18, 1987
priority date (Note) -
Expired
status (Latency Note)
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Abstract
A proximity detector includes a magnet having steel or iron pole piece plates mounted at front and rear pole ends of the magnet, and a silicon integrated circuit mounted to the outer surface of the front pole piece centered about at the magnet pole axis. The integrated circuit includes two essentially identical Hall elements having outputs connected series opposing, i.e. differentially rather than aiding, so that distortion of the magnet field ambient to the integrated circuit caused by a ferromagnetic article passing by results in a gradient field between the Hall elements producing a differential output signal. The dual Hall element integrated circuit leads to a low differential composite offset voltage while the front pole piece renders the magnetic flux density much more uniform further reducing this dual-Hall-element composite offset voltage.
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- 15 United States
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Patent Owner(s)
| Patent Owner | Address | |
|---|---|---|
| ALLEGRO MICROSYSTEMS INC A CORP OF DE | Not Provided |
International Classification(s)
Inventor(s)
| Inventor Name | Address | # of filed Patents | Total Citations |
|---|---|---|---|
| Gibson, Barbara L | Dorchester, MA | 1 | 34 |
| Higgs, Jacob K | Salisbury, NH | 9 | 227 |
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|---|---|---|---|
| Surcharge after expiration - Late payment is unavoidable | $700.00 | $350.00 | $175.00 |
| Surcharge after expiration - Late payment is unintentional | $1,640.00 | $820.00 | $410.00 |
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