US4831652A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stereo expansion circuit selection switch
Assignee: RCA Licensing Corp
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Filing: 1988-05-05
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Granted: 1989-05-16
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Expires: 2008-05-05
Abstract
Abstract A stereo expansion circuit selection switch includes a transmission gate to cross couple the right and left channels as needed for stereo expansion.
Inventors
- 👤 Mark R. Anderson
- 👤 Robert E. Morris, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 17:58
CPC Classifications
H; H04; H04S; H04S5/00; H04S1/00; H04S1/002
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
113 words
In a stereo expansion circuit having a right amplifying channel and a left amplifying channel, said right and left channels each having a first input terminal for receiving a stereo signal component, each of said channels also having a second input terminal for receiving a stereo signal component, a selection device comprising; transmission gate switching means including a transmission gate coupling said second input terminals for providing expanded stereo when said switching means is closed and nonexpanded audio when said switching means is open; control voltage means for actuating said transmission gate; high impedance means shunting said transmission gate for preventing audible switching transients; and filter means in series with said transmission gate.
Claim 2
Dependent Claim
113 words
In a stereo expansion circuit having a right amplifying channel and a left amplifying channel, said right and left channels each having a first input terminal for receiving a stereo signal component, each of said channels also having a second input terminal for receiving a stereo signal component, a selection device comprising; transmission gate switching means including a transmission gate coupling said second input terminals for providing expanded stereo when said switching means is closed and nonexpanded audio when said switching means is open; control voltage means for actuating said transmission gate; high impedance means shunting said transmission gate for preventing audible switching transients; and filter means in series with said transmission gate.
Claim 3
Dependent Claim
14 words
The selection device of claim 1 wherein said high impedance means is a resistor.
Claim 4
Dependent Claim
93 words
In a stereo expansion circuit having a right amplifying channel and a left amplifying channel, said right and left channels each having a non-inverting input terminal for receiving a stereo signal component, each of said channels also having an inverting input terminal for receiving a stereo signal component, a selection device comprising; transmission gate switching means coupling said inverting input terminals for providing expanded stereo when said switching means is closed and nonexpanded audio when said switching means is open; filter means arranged between said switching means and one of said amplifying channels.
Claim 5
Dependent Claim
93 words
In a stereo expansion circuit having a right amplifying channel and a left amplifying channel, said right and left channels each having a non-inverting input terminal for receiving a stereo signal component, each of said channels also having an inverting input terminal for receiving a stereo signal component, a selection device comprising; transmission gate switching means coupling said inverting input terminals for providing expanded stereo when said switching means is closed and nonexpanded audio when said switching means is open; filter means arranged between said switching means and one of said amplifying channels.
Claim 6
Dependent Claim
14 words
The selection device of claim 3 wherein said filter means is an R-C filter.
Claim 7
Dependent Claim
15 words
The selection device of claim 4 wherein said filter means is a series R-C filter.
Claim 8
Dependent Claim
72 words
In a stereo expansion circuit having right and left channels, each channel including amplifier means having an output terminal and a non-inverting input terminal for receiving stereo signals, and an inverting input terminal for receiving feedback signals from the respective output terminals, an improvement comprising: switch means cross coupling said inverting input terminals for providing expanded stereo when said switch means is closed and nonexpanded stereo when said switch means is open.
Claim 9
Dependent Claim
72 words
In a stereo expansion circuit having right and left channels, each channel including amplifier means having an output terminal and a non-inverting input terminal for receiving stereo signals, and an inverting input terminal for receiving feedback signals from the respective output terminals, an improvement comprising: switch means cross coupling said inverting input terminals for providing expanded stereo when said switch means is closed and nonexpanded stereo when said switch means is open.
Claim 10
Dependent Claim
12 words
The improvement of claim 6 wherein said amplifier means are operational amplifiers.
Claim 11
Dependent Claim
13 words
The improvement of claim 7 wherein said switch means is a transmission gate.
Claim 12
Dependent Claim
17 words
The improvement of claim 8 further including filter means arranged between said transmission gate and said amplifiers.
Claim 13
Dependent Claim
14 words
The improvement of claim 9 wherein said filter means is a series R-C filter.
Claim 14
Dependent Claim
13 words
The improvement of claim 10 further including high impedance shunting said transmission gate.
Claim 15
Dependent Claim
13 words
The improvement of claim 11 wherein said high impedance means is a resistor.
Claim 16
Dependent Claim
14 words
The improvement of claim 8 further including high impedance means shunting said transmission gate.
Claim 17
Dependent Claim
13 words
The improvement of claim 13 wherein said high impedance means is a resistor.
References Cited (Backward Citations)
US3417203A
Cited
US4495637A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-05-15 | 1992-11-14 | 1993-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-15 | 1996-11-14 | 1997-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-15 | 2000-11-14 | 2001-05-16 | $7700.00 | Window Closed / Lapsed |