US5352986A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Closed loop power controller
Assignee: Digital Fidelity Inc
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Filing: 1993-01-22
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Granted: 1994-10-04
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Expires: 2013-01-22
Abstract
Abstract A power controller includes a closed-loop system having a summer to sum an input signal with a derived output signal to produce a difference signal. A comparator compares the difference signal with a reference signal to produce a digital signal representative of the polarity difference between the difference signal and the reference signal. Two switching networks respond to the digital signal to produce high energy outputs representative of the digital signal which are used to reduce the level of the difference signal in a frequency band of interest at the comparator. A low pass filter between the high energy outputs and the comparator attenuates high-frequency noise. A low-pass filter of at least the third order, connected in the closed loop, enhances the signal-to-noise ratio. In a specific application the power controller is a power amplifier and the input signal is in the audio frequency range.
Inventors
- 👤 Onkar S. Modgil
- 👤 Robert G. Nelson
- 👤 Margaret S. Reif
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:44
CPC Classifications
H; H03; H03M; H03M3/00; H03M3/30; H03M3/39; H03M3/412; H03M3/422; H03M3/43; H03M3/432; H03F; H03F1/00; H03F1/08; H03F1/083; H03F3/00; H03F3/20; H03F3/21; H03F3/217; H03M3/436; H03M3/438
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
159 words
A closed-loop system, having an input and an output, for controlling power comprising, means to sum an input signal with a derived output signal to produce a difference signal representative of the polarity of the difference between said input signal and said derived output signal, means for producing an asynchronous digital signal representative of the polarity of said difference signal, at least two switching networks, said switching networks having high energy outputs and being responsive to said asynchronous digital signal to reduce the level of said difference signal in a frequency band of interest at said means of producing the said asynchronous digital signal; and a low-pass filter at least of the third order between said high energy outputs and said means of producing the said asynchronous digital signal to attenuate high-frequency noise, said low-pass filter being in said closed loop to enhance the signal-to-noise ratio at said output of said closed-loop system and modified to maintain loop stability.
Claim 2
Dependent Claim
159 words
A closed-loop system, having an input and an output, for controlling power comprising, means to sum an input signal with a derived output signal to produce a difference signal representative of the polarity of the difference between said input signal and said derived output signal, means for producing an asynchronous digital signal representative of the polarity of said difference signal, at least two switching networks, said switching networks having high energy outputs and being responsive to said asynchronous digital signal to reduce the level of said difference signal in a frequency band of interest at said means of producing the said asynchronous digital signal; and a low-pass filter at least of the third order between said high energy outputs and said means of producing the said asynchronous digital signal to attenuate high-frequency noise, said low-pass filter being in said closed loop to enhance the signal-to-noise ratio at said output of said closed-loop system and modified to maintain loop stability.
Claim 3
Dependent Claim
165 words
A closed-loop system, having an input and an analog output, for controlling power comprising, means to sum a signal applied to the input with a signal derived from the analog output to produce a difference signal representative of the polarity of the difference between said input signal and said derived output signal, means for producing a digital signal representative of the polarity of said difference signal, at least two switching networks, said switching networks having high energy outputs and being responsive to said digital signals, to reduce the level of said difference signal in the frequency band of interest at the means for producing the said digital signals, a low-pass filter between said high energy outputs and the said analog output to attenuate high-frequency noise, and a low-pass filter at least of the third order in said closed loop to enhance the signal-to-noise ratio at said output of said closed-loop system, said low-pass filter at least of the third order modified to maintain loop stability.
Claim 4
Dependent Claim
165 words
A closed-loop system, having an input and an analog output, for controlling power comprising, means to sum a signal applied to the input with a signal derived from the analog output to produce a difference signal representative of the polarity of the difference between said input signal and said derived output signal, means for producing a digital signal representative of the polarity of said difference signal, at least two switching networks, said switching networks having high energy outputs and being responsive to said digital signals, to reduce the level of said difference signal in the frequency band of interest at the means for producing the said digital signals, a low-pass filter between said high energy outputs and the said analog output to attenuate high-frequency noise, and a low-pass filter at least of the third order in said closed loop to enhance the signal-to-noise ratio at said output of said closed-loop system, said low-pass filter at least of the third order modified to maintain loop stability.
Claim 5
Dependent Claim
40 words
A closed-loop system as set forth in claim 2 or 1 in which said switching networks are responsive to said digital signal synchronous with a clock producing pulses at a rate significantly higher than the frequencies of the input signal.
Claim 6
Dependent Claim
15 words
A closed-loop system as set forth in claim 1 wherein said low-pass filter is underdamped.
Claim 7
Dependent Claim
18 words
A closed-loop system as set forth in claim 2 wherein said low-pass filter in the closed-loop is underdamped.
Claim 8
Dependent Claim
155 words
A closed-loop system, having an input and an output, for controlling power comprising, means to sum a signal applied to the input with a signal derived from the output to produce a difference signal, means for generating a reference signal, comparison means for comparing said difference signal with said reference signal to produce a digital signal representative of the polarity difference between said difference signal and said reference signal, at least two switching networks, said switching networks having high energy outputs representative of said digital signal, to reduce the level of said difference signal in the frequency band of interest at the means for producing the said digital signal, a low-pass filter between said high energy outputs and said means for producing the said digital signal to attenuate high-frequency noise, and a low-pass filter of at least the third order in the closed loop to enhance the signal-to-noise ratio and modified to maintain loop stability.
Claim 9
Dependent Claim
155 words
A closed-loop system, having an input and an output, for controlling power comprising, means to sum a signal applied to the input with a signal derived from the output to produce a difference signal, means for generating a reference signal, comparison means for comparing said difference signal with said reference signal to produce a digital signal representative of the polarity difference between said difference signal and said reference signal, at least two switching networks, said switching networks having high energy outputs representative of said digital signal, to reduce the level of said difference signal in the frequency band of interest at the means for producing the said digital signal, a low-pass filter between said high energy outputs and said means for producing the said digital signal to attenuate high-frequency noise, and a low-pass filter of at least the third order in the closed loop to enhance the signal-to-noise ratio and modified to maintain loop stability.
Claim 10
Dependent Claim
22 words
A closed-loop system as set forth in claim 6 in which said low-pass filter of at least the third order is underdamped.
Claim 11
Dependent Claim
19 words
A closed-loop system as set forth in claim 6 or 7 wherein the closed-loop system includes a pulse-width modulator.
Claim 12
Dependent Claim
32 words
A closed-loop system as set forth in claim 6 or 7, wherein said low-pass filter of at least the third order has more than 180 degrees of phase lag at certain frequencies.
Claim 13
Dependent Claim
35 words
A closed-loop system as set forth in claim 1, 2, 3, 4 or 5 wherein said low-pass filter of at least the third order has more than 180 degrees of phase lag at certain frequencies.
Claim 14
Dependent Claim
30 words
A closed-loop system as set forth in claim 8 wherein said low-pass filter of at least the third order has more than 180 degrees of phase lag at certain frequencies.
Claim 15
Dependent Claim
19 words
A closed-loop system as set forth in claim 10 including means for reducing the phase lag below 180 degrees.
Claim 16
Dependent Claim
19 words
A closed-loop system as set forth in claim 11 including means for reducing the phase lag below 180 degrees.
Claim 17
Dependent Claim
19 words
A closed-loop system as set forth in claim 9 including means for reducing the phase lag below 180 degrees.
Claim 18
Dependent Claim
35 words
A closed-loop system as set forth in claim 1, 2, 3, 4, 5, 6, or 7, wherein the closed loop system is a power amplifier and the input signal is in the audio frequency range.
Claim 19
Dependent Claim
27 words
A closed-loop system as set forth in claim 8 wherein the closed-loop system is a power amplifier and the input signal is in the audio frequency range.
Claim 20
Dependent Claim
27 words
A closed-loop system as set forth in claim 9 wherein the closed-loop system is a power amplifier and the input signal is in the audio frequency range.
Claim 21
Dependent Claim
27 words
A closed-loop system as set forth in claim 14 wherein the closed-loop system is a power amplifier and the input signal is in the audio frequency range.
Claim 22
Dependent Claim
27 words
A closed-loop system as set forth in claim 10 wherein the closed-loop system is a power amplifier and the input signal is in the audio frequency range.
Claim 23
Dependent Claim
27 words
A closed-loop system as set forth in claim 12 wherein the closed-loop system is a power amplifier and the input signal is in the audio frequency range.
Claim 24
Dependent Claim
27 words
A closed-loop system as set forth in claim 12 wherein the closed-loop system is a power amplifier and the input signal is in the audio frequency range.
Claim 25
Dependent Claim
27 words
A closed-loop system as set forth in claim 13 wherein the closed-loop system is a power amplifier and the input signal is in the audio frequency range.
References Cited (Backward Citations)
US4724396A
Cited
US5218315A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-10-03 | 1998-04-04 | 1998-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-10-03 | 2002-04-04 | 2002-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-10-03 | 2006-04-04 | 2006-10-04 | $7700.00 | Window Closed / Lapsed |