US4450411A
Expired / Lapsed
US
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Automatic calibration system for signal amplifier circuits
Assignee: Bank One Kentucky NA
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Filing: 1982-07-27
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Granted: 1984-05-22
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Expires: 2002-07-27
Abstract
Abstract An automatic calibration system for signal amplifier circuits uses a single complex power signal to replace the formerly used four separate sinewave frequencies and a square wave signal. In the illustrated embodiment of the invention, the power signal is recorded on a magnetic tape and is played back through reproduce equalizer circuits which apply the reproduced signal to a tracking frequency converter to produce an amplitude measurement of each of the preselected frequency components forming the complex power signal. The amplitude measurements are referenced to the power signal's actual harmonic content to enable an adjustment of the equalizer circuits to produce a minimum error in the playback signal. A bandpass phase response measurement is also performed on the reproduced signal by comparing the phase difference between the reproduced signal and a synthesized power signal after the amplitude compensation produced by the amplitude measurements.
Inventors
- 👤 Robert N. Spurr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 12:35
CPC Classifications
G; G01; G01R; G01R35/00; G01R35/005; G11; G11B; G11B5/00; G11B5/02; G11B5/027; G11B5/035
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
111 words
A calibration system for signal amplifier circuits comprising signal generating means for producing a single complex output signal having a plurality of predetermined frequencies at respective preselected amplitudes, recording means for recording said output signal, reproducing means for reproducing said recorded output signal, signal amplifier means having an adjustable gain characteristic for amplifying said reproduced output signal, frequency conversion means for measuring the frequency components of said amplified output signal corresponding to said predetermined frequencies and means for providing a correction feedback control for adjusting said gain of said signal amplifier means to produce an amplitude correspondence of said amplified output signal to said output signal from said signal generating means.
Claim 2
Dependent Claim
111 words
A calibration system for signal amplifier circuits comprising signal generating means for producing a single complex output signal having a plurality of predetermined frequencies at respective preselected amplitudes, recording means for recording said output signal, reproducing means for reproducing said recorded output signal, signal amplifier means having an adjustable gain characteristic for amplifying said reproduced output signal, frequency conversion means for measuring the frequency components of said amplified output signal corresponding to said predetermined frequencies and means for providing a correction feedback control for adjusting said gain of said signal amplifier means to produce an amplitude correspondence of said amplified output signal to said output signal from said signal generating means.
Claim 3
Dependent Claim
26 words
A calibration system as set forth in claim 1 wherein said single complex output signal includes a plurality of harmonics and a predetermined single frequency signal.
Claim 4
Dependent Claim
47 words
A calibration system as set forth in claim 1 wherein said frequency conversion means includes a phase locked loop, means for locking said loop to a predetermined harmonic of said amplified output signal and means for producing an output representative of the amplitude of said predetermined harmonic.
Claim 5
Dependent Claim
47 words
A calibration system as set forth in claim 3 wherein said means for producing an output includes an RMS voltmeter for displaying an output corresponding to the difference in amplitude between a harmonic in said amplified output signal and a corresponding harmonic from said phase locked loop.
Claim 6
Dependent Claim
37 words
A calibration system as set forth in claim 1 wherein said single complex output signal includes a 0.2 bandedge harmonic, a 0.6 bandedge harmonic, a bandedge harmonic and a low frequency signal below said 0.2 bandedge harmonic.
Claim 7
Dependent Claim
33 words
A calibration system as set forth in claim 1 and further includes means for measuring the phase of said amplified output signal to determine a bandpass phase response of said signal amplifier means.
Claim 8
Dependent Claim
76 words
A calibration system as set forth in claim 6 wherein said means for measuring the phase includes means for synthesizing a duplicate of said single complex signal, means for comparing said synthesized complex signal with said amplified output signal and means for providing a second correction feedback control for adjusting the phase of said signal amplifier means to produce a phase correspondence of said amplified output signal to said output signal from said signal generating means.
Claim 9
Dependent Claim
45 words
A calibration system as set forth in claim 7 wherein said means for producing a second feedback correction control includes a DC voltmeter for displaying an output corresponding to the phase difference between said amplified output signal and said synthesized duplicate of said complex signal.
Claim 10
Dependent Claim
47 words
A calibration system as set forth in claim 8 wherein said frequency conversion means includes a phase locked loop, means for locking said loop to a predetermined harmonic of said amplified output signal and means for producing an output representative of the amplitude of said predetermined harmonic.
Claim 11
Dependent Claim
36 words
A calibration system as set forth in claim 9 wherein frequency conversion means and said means for measuring the phase each includes a respective filter for removing intermodulation products prior to providing a feedback correction control.
Claim 12
Dependent Claim
130 words
A calibration signal for signal amplifier circuits comprising signal generating means for producing a single output signal having a plurality of predetermined frequencies at a preselected amplitude, signal amplifier means having an adjustable gain characteristic for amplifying said output signal, frequency conversion means for measuring the frequency components of said amplified output signal corresponding to said predetermined frequencies, said frequency conversion means including a phase-lock loop, means for locking said loop to a predetermined harmonic of said amplified output signal and means for producing an output representative of the amplitude of said predetermined harmonic, and means for providing a correction feedback control for adjusting said gain of said signal amplifier means to produce an amplitude correspondence of said amplified output signal to said output signal from said signal generating means.
Claim 13
Dependent Claim
130 words
A calibration signal for signal amplifier circuits comprising signal generating means for producing a single output signal having a plurality of predetermined frequencies at a preselected amplitude, signal amplifier means having an adjustable gain characteristic for amplifying said output signal, frequency conversion means for measuring the frequency components of said amplified output signal corresponding to said predetermined frequencies, said frequency conversion means including a phase-lock loop, means for locking said loop to a predetermined harmonic of said amplified output signal and means for producing an output representative of the amplitude of said predetermined harmonic, and means for providing a correction feedback control for adjusting said gain of said signal amplifier means to produce an amplitude correspondence of said amplified output signal to said output signal from said signal generating means.
Claim 14
Dependent Claim
26 words
A calibration system as set forth in claim 11 wherein said single complex output signal includes a plurality of harmonics and a predetermined single frequency signal.
Claim 15
Dependent Claim
47 words
A calibration system as set forth in claim 11 wherein said means for producing an output includes an RMS voltmeter for displaying an output corresponding to the difference in amplitude between a harmonic in said amplified output signal and a corresponding harmonic from said phase locked loop.
Claim 16
Dependent Claim
37 words
A calibration system as set forth in claim 11 wherein said single complex output signal includes a 0.2 bandedge harmonic, a 0.6 bandedge harmonic, a bandedge harmonic and a low frequency signal below said 0.2 bandedge harmonic.
Claim 17
Dependent Claim
33 words
A calibration system as set forth in claim 11 and further includes means for measuring the phase of said amplified output signal to determine a bandpass phase response of said signal amplifier means.
Claim 18
Dependent Claim
76 words
A calibration system as set forth in claim 15 wherein said means for measuring the phase includes means for synthesizing a duplicate of said single complex signal, means for comparing said synthesized complex signal with said amplified output signal and means for providing a second correction feedback control for adjusting the phase of said signal amplifier means to produce a phase correspondence of said amplified output signal to said output signal from said signal generating means.
Claim 19
Dependent Claim
45 words
A calibration system as set forth in claim 16 wherein said means for producing a second feedback correction control includes a DC voltmeter for displaying an output corresponding to the phase difference between said amplified output signal and said synthesized duplicate of said complex signal.
Claim 20
Dependent Claim
47 words
A calibration system as set forth in claim 17 wherein said frequency conversion means includes a phase locked loop, means for locking said loop to a predetermined harmonic of said amplified output signal and means for producing an output representative of the amplitude of said predetermined harmonic.
Claim 21
Dependent Claim
36 words
A calibration system as set forth in claim 18 wherein frequency conversion means and said means for measuring the phase each include a respective filter for removing intermodulation products prior to providing a feedback correction control.
References Cited (Backward Citations)
US3725784A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-05-22 | 1987-11-21 | 1988-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-22 | 1991-11-21 | 1992-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-22 | 1995-11-21 | 1996-05-22 | $7700.00 | Window Closed / Lapsed |