US4506236A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Composite filter/differentiator
Assignee: Unisys Corp
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Filing: 1982-12-15
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Granted: 1985-03-19
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Expires: 2002-12-15
Abstract
Abstract There is shown and described a relatively simple electronic circuit using few discrete components which is used to replace the filter and delay line differentiator in existing circuits. The new circuit provides a simultaneous output of even and odd signals which have the same transfer function except for the derivative operation. The circuit is especially useful in read and write channels of a disk drive apparatus.
Inventors
- 👤 Robert L. Cloke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:14
CPC Classifications
H; H03; H03H; H03H7/00; H03H7/01; H03H7/0115; H03H7/48
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
84 words
An open-ended composite filter/differentiator circuit which simultaneously produces an even function and an odd function of a transfer function supplied thereto in a read/write channel, comprising energy source means, resistance means connected to said source so as to develop the odd functions relative thereto, and inductance means and capacitance means connected together to form an open-ended impedance network which is connected to said source means and to said resistance means so as to develop the even function across the open-ended portion of said network.
Claim 2
Dependent Claim
84 words
An open-ended composite filter/differentiator circuit which simultaneously produces an even function and an odd function of a transfer function supplied thereto in a read/write channel, comprising energy source means, resistance means connected to said source so as to develop the odd functions relative thereto, and inductance means and capacitance means connected together to form an open-ended impedance network which is connected to said source means and to said resistance means so as to develop the even function across the open-ended portion of said network.
Claim 3
Dependent Claim
40 words
The circuit recited in claim 1 wherein, said energy source means is a constant voltage source, and said resistance means includes a resistor connected in a series with said source means and said odd function is developed across said resistor.
Claim 4
Dependent Claim
21 words
The circuit recited in claim 1 wherein, said inductance means and said capacitance means comprise an inductor and capacitor ladder circuit.
Claim 5
Dependent Claim
17 words
The circuit recited in claim 3 wherein, said ladder circuit comprises at least a 3-pole Bessel design.
Claim 6
Dependent Claim
19 words
The circuit recited in claim 1 wherein, said capacitance means produces said even function into an open circuit configuration.
Claim 7
Dependent Claim
19 words
The circuit recited in claim 1 wherein, said resistance means produces said odd function into an open circuit configuration.
Claim 8
Dependent Claim
64 words
The circuit recited in claim 1 including, amplifier means for supplying signals to said source means, first detector means connected to receive said odd function from said capacitance means, second detector means connected to receive said even function from said inductance means, and qualification logic means connected to receive signals from each of said first and second detector means to selectively produce output signals.
Claim 9
Dependent Claim
14 words
The circuit recited in claim 7 wherein, said qualification means produces digital output signals.
Claim 10
Dependent Claim
39 words
The circuit recited in claim 1 wherein, said energy source means is a constant current source, and said resistance means includes a resistor connected in parallel with said source means and said odd function is developed through said resistor.
References Cited (Backward Citations)
US2609448A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-03-18 | 1988-09-17 | 1989-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-03-18 | 1992-09-17 | 1993-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-03-18 | 1996-09-17 | 1997-03-19 | $7700.00 | Window Closed / Lapsed |