US4038594A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Distortionless sine wave amplification
Assignee: Xerox Corp
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Filing: 1975-09-26
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Granted: 1977-07-26
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Expires: 1995-09-26
Abstract
Abstract A power supply circuit for generating true sine wave signals by regulating the average value of the signal, whereby the RMS value of the signal is regulated accordingly. By monitoring the circuit through the load, represented by a monitored voltage value, a feedback network is coupled to a variable resistor in conjunction with other circuitry to maintain a constant voltage ratio to the power transformer assuring a properly shaped wave at a larger or smaller variation.
Inventors
- 👤 Halsey P. Quinn
- 👤 Donald B. Levinson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 11:31
CPC Classifications
G; G05; G05F; G05F1/00; G05F1/66; G03; G03G; G03G15/00; G03G15/02; G03G15/0266
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
319 words
A power supply for generating true sine wave signals comprising: means for supplying AC current to a load, means coupled to said supplying means for monitoring the amount of current flowing through said load, feedback circuit means coupled to said monitoring means and said supplying means to allow an adjustment of said AC current to said load, said feedback circuit means including variable resistance means for effecting a linear current change in said load to effect said generation of true sine wave signals, said feedback circuit means also including first circuit means coupled between said variable resistance means and said supplying means for adjusting the input supply current to said supplying means, said first circuit means and said variable resistance means comprising a resistance dividing network so that when said variable resistance means is varied the current supplied to said supplying means is varied accordingly, said first circuit means also including an operational amplifier, a pass transistor whose base element is connected to the output of said operational amplifier and whose emitter and collector elements are in series with the supply current to said supplying means, a first resistor connected to said emitter element to complete said series connection to said supplying means, said first resistor-transistor emitter element junction also connected to one input of said operational amplifier, a second resistor connected to the collector of said transistor and the other input of said operational amplifier, this input junction also connected to said variable resistance means, and said operational amplifier, upon change of resistance of said variable resistance means, will cause the ratio of the voltage across said first resistor and said variable resistance means to be constant, and said feedback circuit means also including second circuit means coupled between said monitoring means and said variable resistance means for adjusting the signal applied to said variable resistance means in response to the change in current through said monitoring means.
Claim 2
Dependent Claim
319 words
A power supply for generating true sine wave signals comprising: means for supplying AC current to a load, means coupled to said supplying means for monitoring the amount of current flowing through said load, feedback circuit means coupled to said monitoring means and said supplying means to allow an adjustment of said AC current to said load, said feedback circuit means including variable resistance means for effecting a linear current change in said load to effect said generation of true sine wave signals, said feedback circuit means also including first circuit means coupled between said variable resistance means and said supplying means for adjusting the input supply current to said supplying means, said first circuit means and said variable resistance means comprising a resistance dividing network so that when said variable resistance means is varied the current supplied to said supplying means is varied accordingly, said first circuit means also including an operational amplifier, a pass transistor whose base element is connected to the output of said operational amplifier and whose emitter and collector elements are in series with the supply current to said supplying means, a first resistor connected to said emitter element to complete said series connection to said supplying means, said first resistor-transistor emitter element junction also connected to one input of said operational amplifier, a second resistor connected to the collector of said transistor and the other input of said operational amplifier, this input junction also connected to said variable resistance means, and said operational amplifier, upon change of resistance of said variable resistance means, will cause the ratio of the voltage across said first resistor and said variable resistance means to be constant, and said feedback circuit means also including second circuit means coupled between said monitoring means and said variable resistance means for adjusting the signal applied to said variable resistance means in response to the change in current through said monitoring means.
Claim 3
Dependent Claim
74 words
The power supply as set forth in claim 1 wherein said second circuit means comprises: second operational circuit means coupled to said monitoring means and to a reference voltage source, the output of said second operational circuit being coupled to said variable resistance means, for comparing the voltage signal generated by said monitoring means representative of current flowing therethrough and generating an error signal to said variable resistance means to change its resistance accordingly.
Claim 4
Dependent Claim
65 words
The power supply as set forth in claim 2 wherein said variable resistance means comprises: light emitting diode means for generating a variable light signal in response to the amount of current flowing through said load, and light depending resistance means in close cooperation with said diode means for changing its value of resistance in direct relation to the light output from said diode means.
Claim 5
Dependent Claim
36 words
The power supply as set forth in claim 2 wherein said variable resistance means comprises: field effect transistor means wherein the channel resistance is varied in response to the amount of current flowing through said load.
Claim 6
Dependent Claim
15 words
The power supply as set forth in claim 2 wherein said load is a corotron.
Claim 7
Dependent Claim
65 words
The power supply as set forth in claim 1 wherein said variable resistance means comprises: light emitting diode means for generating a variable light signal in response to the amount of current flowing through said load, and light depending resistance means in close cooperation with said diode means for changing its value of resistance in direct relation to the light output from said diode means.
Claim 8
Dependent Claim
36 words
The power supply as set forth in claim 1 wherein said variable resistance means comprises: field effect transistor means wherein the channel resistance is varied in response to the amount of current flowing through said load.
Claim 9
Dependent Claim
15 words
The power supply as set forth in claim 1 wherein said load is a corotron.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-07-25 | 1981-01-24 | 1981-07-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-25 | 1985-01-24 | 1985-07-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-25 | 1989-01-24 | 1989-07-26 | $7700.00 | Window Closed / Lapsed |