US4710727A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Nonlinear distortion synthesizer using over-threshold power-function feedback
Assignee: Aardvark Audio Inc
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Filing: 1986-08-01
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Granted: 1987-12-01
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Expires: 2006-08-01
Abstract
Abstract A nonlinear distortion synthesizer having an amplifier and one or more over-threshold power-function negative-feedback paths. Each negative-feedback path provides a feedback signal which is separately adjustable for each signal polarity. The feedback signal for each polarity is proportional to a power function of the portion of the output signal which exceeds a predetermined threshold.
Inventors
- 👤 Thomas E. Rutt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 18:06
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/32; H03F1/3241; H03F1/3264; H03F1/327; H03F1/3276
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
133 words
A circuit, responsive to an input signal, for use with an amplifier, which circuit comprises; a signal-mixing means for providing an input signal to the amplifier in response to the input signal and at least one over-threshold power-function negative feedback signal; and at least one negative feedback means for providing the at least one over-threshold power-function negative feedback signal in response to the amplifier output signal, which comprises: (a) a peak-pass means, responsive to the amplifier output signal, for picking off predetermined portions of the amplifier output signal, to produce a peak-over-threshold signal, and (b) a polarity-preserving power-function means, responsive to the peak-over-threshold signal, for producing the at least one over-threshold power-function negative feedback signal having an amplitude which is proportional to the peak-over-threshold signal level raised to a power greater than one.
Claim 2
Dependent Claim
133 words
A circuit, responsive to an input signal, for use with an amplifier, which circuit comprises; a signal-mixing means for providing an input signal to the amplifier in response to the input signal and at least one over-threshold power-function negative feedback signal; and at least one negative feedback means for providing the at least one over-threshold power-function negative feedback signal in response to the amplifier output signal, which comprises: (a) a peak-pass means, responsive to the amplifier output signal, for picking off predetermined portions of the amplifier output signal, to produce a peak-over-threshold signal, and (b) a polarity-preserving power-function means, responsive to the peak-over-threshold signal, for producing the at least one over-threshold power-function negative feedback signal having an amplitude which is proportional to the peak-over-threshold signal level raised to a power greater than one.
Claim 3
Dependent Claim
25 words
The circuit of claim 1 wherein the peak-pass means comprises means for picking off predetermined portions of the amplifier output above a first predetermined threshold.
Claim 4
Dependent Claim
25 words
The circuit of claim 1 wherein the peak-pass means comprises means for picking off predetermined portions of the amplifier output below a second predetermined threshold.
Claim 5
Dependent Claim
17 words
The circuit of claim 2 wherein the peak-pass means comprises means for varying the first predetermined threshold.
Claim 6
Dependent Claim
17 words
The circuit of claim 3 wherein the peak-pass means comprises means for varying the second predetermined threshold.
Claim 7
Dependent Claim
22 words
The circuit of claim 2 wherein the peak-pass means further comprises means for varying the amplitude of the predetermined portions picked off.
Claim 8
Dependent Claim
22 words
The circuit of claim 3 wherein the peak-pass means further comprises means for varying the amplitude of the predetermined portions picked off.
Claim 9
Dependent Claim
88 words
The circuit of claim 1 wherein the peak-pass means further comprises: (a) means for picking off first predetermined portions of the amplifier output above a first predetermined threshold; (b) means for picking off second predetermined portions of the amplifier output below a second predetermined threshold; (c) means for varying the first predetermined threshold; (d) means for varying the second predetermined threshold; (e) means for varying the amplitude of the first predetermined portions picked off; and, (f) means for varying the amplitude of the second predetermined portions picked off.
Claim 10
Dependent Claim
30 words
The circuit of claim 1 wherein the polarity-preserving power-function means further comprises means for producing an over-threshold power-function feedback signal having the same polarity as the predetermined portions picked off.
Claim 11
Dependent Claim
29 words
The circuit of claim 1 wherein the polarity-preserving power-function means further comprises means for producing an over-threshold power-function feedback signal having opposite polarity to the predetermined portions picked off.
Claim 12
Dependent Claim
34 words
The circuit of claim 1 wherein the polarity-preserving power function means provides an over-threshold power-function negative feedback signal having an amplitude which is proportional to the peak-over-threshold signal level raised to the third power.
Claim 13
Dependent Claim
31 words
The circuit of claim 1 which further comprises a linear feedback means, responsive to the amplifier output signal, for producing a linear feedback signal which is applied to the signal-mixing means.
Claim 14
Dependent Claim
59 words
The circuit of claim 1 wherein the peak-pass means comprises: a resistor which is connected at one end to the amplifier output and connected at the other end to a first end of a diode and to a second resistor in series with a bias means, the other end of the diode comprising the output of the peak-pass means.
Claim 15
Dependent Claim
13 words
The circuit of claim 13 wherein the bias means is a voltage source.
Claim 16
Dependent Claim
13 words
The circuit of claim 13 wherein the bias means is a current source.
Claim 17
Dependent Claim
88 words
The circuit of claim 1 wherein the polarity-preserving power-function means provides an over-threshold power-function negative feedback signal having an amplitude which is proportional to the peak-over-threshold signal level raised to the second power, which polarity-preserving power-function means comprises: an absolute value means, responsive to the output of the peak-pass means; and an analog multiplier, responsive at an input to the output of the peak-pass means and responsive at a second input to the output of the absolute value means, for producing the output of the polarity-preserving power-function means.
Claim 18
Dependent Claim
135 words
The circuit of claim 1 wherein the polarity-preserving power-function means provides an over-threshold power-function negative feedback signal having an amplitude which is proportional to the peak-over-threshold signal level raised to the third power, which polarity-preserving power-function means comprises: a first absolute value means, responsive to the output of the peak-pass means; a first analog multiplier, responsive at an input to the output of the peak-pass means and responsive at a second input to the output of the first absolute value means; a second absolute value means, responsive to the output of the peak-pass means; and a second analog multiplier, responsive at an input to the output of the first analog multiplier and responsive at a second input to the output of the second absolute value means, for producing the output of the polarity-preserving power-function means.
Claim 19
Dependent Claim
105 words
The circuit of claim 1 wherein the polarity-preserving power-function means provides an over-threshold power-function negative feedback signal having an amplitude which is proportional to the peak-over-threshold signal level raised to the third power, which polarity-preserving power-function means comprises; a first analog multiplier, responsive at an input to the output of the peak-pass means and responsive at a second input to the output of the peak-pass means; and a second analog multiplier, responsive at an input to the output of the first analog multiplier and responsive at a second input to the output of the peak-pass means, for producing the output of the polarity-preserving power-function means.
Claim 20
Dependent Claim
136 words
The circuit of claim 1 wherein the polarity-preserving power-function means provides an over-threshold power-function negative feedback signal having an amplitude which is proportional to the peak-over-threshold signal level raised to the fourth power, which polarity-preserving power-function means comprises: a first absolute value means, responsive to the output of the peak-pass means; a first analog multiplier, responsive at an input to the output of the peak-pass means and responsive at a second input to the output of the first absolute value means; a second absolute value means, responsive to the output of the first analog multiplier; and a second analog multiplier, responsive at an input to the output of the first analog multiplier and responsive at a second input to the output of the second absolute value means, for producing the output of the polarity-preserving power-function means.
Claim 21
Dependent Claim
69 words
The circuit of claim 2 wherein the polarity-preserving power-function means comprises; a logarithmic converter, responsive to the output of the peak-pass means, for providing a signal proportional to the logarithm of the peak-over-threshold signal level; a scale adjusting means, responsive to the output of the logarithmic converter; and an antilogarithmic converter, responsive to the output of the scale adjusting means, for producing the output of the polarity-preserving power-function means.
Claim 22
Dependent Claim
97 words
The circuit of claim 3 wherein the polarity-preserving power-function means comprises: an inverter circuit, responsive to the output of the peak-pass means, for producing a signal proportional to the additive inverse of the peak-over-threshold signal; a logarithmic converter, responsive to the output of the inverter circuit, for providing a signal proportional to the logarithm of the additive inverse of the peak-over-threshold signal level; a scale adjusting means, responsive to the output of the logarithmic converter; and an antilogarithmic converter, responsive to the output of the scale adjusting means, for producing the output of the polarity-preserving power-function means.
Claim 23
Dependent Claim
56 words
The circuit of claim 3 wherein the polarity-preserving power-function means comprises; an inverter circuit, responsive to the output of the peak-pass means, for producing a signal proportional to the additive inverse of the peak-over-threshold signal; and a power-function means, responsive to the ouput of the inverter circuit, for producing the output of the polarity-preserving power-function means.
References Cited (Backward Citations)
US3211901A
Cited
US3281585A
Cited
US3268830A
Cited
US3284726A
Cited
US3405286A
Cited
GB2040634A
Cited
US4318053A
Cited
US4459557A
Cited
US4506174A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-11-30 | 1991-06-01 | 1991-12-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-11-30 | 1995-06-01 | 1995-12-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-11-30 | 1999-06-01 | 1999-12-01 | $7700.00 | Window Closed / Lapsed |