Patent US4080090A successfully refreshed from Google Patents.
Patent US3745477A successfully refreshed from Google Patents.
US3745477A
Expired / Lapsed
US
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Amplifier apparatus for use with an inductive load
Assignee: REDIFFUSION SIMULATION Inc
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Filing: 1972-01-26
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Granted: 1973-07-10
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Expires: 1992-01-26
Abstract
Abstract Amplifier apparatus for precisely controlling current through an inductive load by means of an RC network which produces a feedback signal accurately simulating the load current. The RC network includes a resistor and a capacitor connected in series across the load and having values related to the parameters of the load such that a signal representative of the instantaneous load current is produced between the resistor and capacitor. The RC network may also include a T resistor arrangement to compensate for any lag occurring between the input and output signals of the amplifier.
Inventors
- 👤 J Freeborn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:47
CPC Classifications
G; G09; G09G; G09G1/00; G09G1/04; H; H03; H03K; H03K4/00; H03K4/06; H03K4/08; H03K4/48; H03K4/60; H03K4/69; H03K4/72; H03K6/00; H03K6/02
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
255 words
Amplifier apparatus for use with an inductive load characterized by inductance L and resistance R and having first and second input terminals, said amplifier apparatus comprising: first and second power supplies; first and second current regulating circuits, each for regulating current flow between first and second terminals thereof; a differential control circuit for differentially controlling said first and second current regulating circuits in response to the summation of a control signal and a feedback signal; a source of reference potential; first connecting means for connecting the first terminals of said first and second current regulating circuits and the first input terminal of the inductive load to said source of reference potential; second connecting means for respectively connecting said first and second power supplies between the second terminals of said first and second current regulating circuits and the second input terminal of the inductive load, a positive terminal of said first power supply and a negative terminal of said second power supply being connected to the load; a resistor and capacitor feedback network for produCing an output voltage which is a predetermined time varying function of an input voltage applied thereto; third connecting means for connecting said feedback network between said source of reference potential and the second input terminal of the inductive load so that the voltage across the load is applied to said feedback network as the input voltage; and fourth connecting means for connecting said feedback network to said differential control circuit so as to supply the output voltage as the feedback signal.
Claim 2
Dependent Claim
255 words
Amplifier apparatus for use with an inductive load characterized by inductance L and resistance R and having first and second input terminals, said amplifier apparatus comprising: first and second power supplies; first and second current regulating circuits, each for regulating current flow between first and second terminals thereof; a differential control circuit for differentially controlling said first and second current regulating circuits in response to the summation of a control signal and a feedback signal; a source of reference potential; first connecting means for connecting the first terminals of said first and second current regulating circuits and the first input terminal of the inductive load to said source of reference potential; second connecting means for respectively connecting said first and second power supplies between the second terminals of said first and second current regulating circuits and the second input terminal of the inductive load, a positive terminal of said first power supply and a negative terminal of said second power supply being connected to the load; a resistor and capacitor feedback network for produCing an output voltage which is a predetermined time varying function of an input voltage applied thereto; third connecting means for connecting said feedback network between said source of reference potential and the second input terminal of the inductive load so that the voltage across the load is applied to said feedback network as the input voltage; and fourth connecting means for connecting said feedback network to said differential control circuit so as to supply the output voltage as the feedback signal.
Claim 3
Dependent Claim
88 words
The apparatus of claim 1 wherein: said feedback network comprises a series combination of a capacitor having capacitance C and a first resistor having resistance R'', the capacitor being connected to said source of reference potential and the resistor being connected to the second input terminal of the inductive load; the values of L, R, C and R'' are related in accordance with the equation L/R R''C; and the feedback signal is derived from a first voltage produced between the resistor and the capacitor in said feedback network.
Claim 4
Dependent Claim
54 words
The apparatus of claim 2 wherein: said feedback network further includes a T resistor circuit connected between said source of reference potential and the second input terminal of the inductive load; and the feedback signal is derived from a combination of the first voltage and a second voltage produced by said T resistor circuit.
Claim 5
Dependent Claim
77 words
The apparatus of claim 3 wherein each of said first and second current regulating circuits comprises: a first transistor having emitter, collector and base electrodes; fifth connecting means for connecting said first transistor, through its emitter and collector electrodes, between one of said first and second floating power supplies and said source of reference potential; and sixth connecting means, including an emitter-follower stage, for connecting said differential control circuit to the base electrode of said first transistor.
Claim 6
Dependent Claim
44 words
The apparatus of claim 4 wherein said sixth connecting means further includes a feedback loop comprising a second transistor having a base electrode connected to the emitter electrode of said first transistor and a collector electrode connected to the input of the emitter-follower stage.
Claim 7
Dependent Claim
62 words
The apparatus of claim 3 further including: first and second unidirectional voltage limiting means; and seventh connecting means for connecting said first and said second unidirectional voltage limiting means between the second input terminal of the inductive load and the first and second current regulating circuits respectively so as to limit voltage excursions at the second input terminal of the inductive load.
Claim 8
Dependent Claim
42 words
The apparatus of claim 6 wherein each of said first and second unidirectional voltage limiting means comprises a series combination of a conventional diode and a Zener diode, each diode having one electrode connected to the like electrode of the other diode.
Claim 9
Dependent Claim
157 words
In combination with apparatus of the type wherein an inductive load characterized by inductance L and resistance R is energized by voltage source means and current regulating means connected in series across the load and wherein the current regulating means is controlled in response to the summation of a command signal and a negative feedback signal proportional to the current flowing through the load, the improvement which comprises: a capacitor having capacitance C and a first resistor having resistance R'', the values L, R, C and R'' being related by the equation L/R R''C; first connecting means for connecting said capacitor and resistor in series across said load whereby the voltage across said capacitor is continuously proportional to the instantaneous current flowing through said load; and second connecting means for connecting said feedback network to said current regulating means so as to supply the voltage across said capacitor to said current regulating means as the feedback signal.
Claim 10
Dependent Claim
157 words
In combination with apparatus of the type wherein an inductive load characterized by inductance L and resistance R is energized by voltage source means and current regulating means connected in series across the load and wherein the current regulating means is controlled in response to the summation of a command signal and a negative feedback signal proportional to the current flowing through the load, the improvement which comprises: a capacitor having capacitance C and a first resistor having resistance R'', the values L, R, C and R'' being related by the equation L/R R''C; first connecting means for connecting said capacitor and resistor in series across said load whereby the voltage across said capacitor is continuously proportional to the instantaneous current flowing through said load; and second connecting means for connecting said feedback network to said current regulating means so as to supply the voltage across said capacitor to said current regulating means as the feedback signal.
Claim 11
Dependent Claim
41 words
The apparatus of claim 8 wherein: a series combination of second and third resistors is connected across said load; and the feedback signal is a combination of the voltage across said capacitor and the voltage between the second and third resistors.
Claim 12
Dependent Claim
34 words
The apparatus of claim 9 wherein junctions between the first resistor and the capacitor, and between the second and third resistors are respectively connected to said current regulating means through fourth and fifth resistors.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-09 | 1977-01-08 | 1977-07-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-09 | 1981-01-08 | 1981-07-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-09 | 1985-01-08 | 1985-07-10 | $7700.00 | Window Closed / Lapsed |