Patent US3879411A successfully refreshed from Google Patents.
Patent US3795826A successfully refreshed from Google Patents.
US3795826A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drive circuit for conducting devices
Assignee: CAV Ltd
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Filing: 1972-07-12
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Granted: 1974-03-05
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Expires: 1992-07-12
Abstract
Abstract A drive circuit for effecting current flow in an inductive circuit comprising a coil the circuit including a power transistor having its emitter collector circuit connected in series with the coil, an input transistor for controlling the power transistor and a resistor for providing a signal representative of the current flowing in the coil. A feed back transistor is supplied with the signal developed across the resistor and provides feed back to the input transistor whereby the mean value of current flowing in the coil will depend upon the magnitude of the input signal applied to the input transistor.
Inventors
- 👤 A Adey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 06:30
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/30; F02D41/38; F02D41/40; F02D41/406; F02D41/407; H; H01; H01F; H01F7/00; H01F7/06; H01F7/064; H01H; H01H47/00; H01H47/22; H01H47/32; H01H47/325; H02; H02K; H02K33/00; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/40
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
147 words
A drive circuit for effecting current flow in an inductive circuit and comprising in combination, a power transistor having its emitter collector circuit connected in series with the inductive circuit, an input transistor for supplying base drive to the power transistor, an input terminal to the drive circuit, the base of said input transistor being connected to said input terminal so as to receive an input signal therefrom, a resistor connected in the emitter collector circuit of said power transistor and across which is developed a signal representative of the current flowing in the inductive circuit, and negative feedback means controlled by the signal developed across said resistor for opposing change in the input signal applied to the base of the input transistor whereby the mean value of current flowing in the inductive circuit will depend upon the magnitude of a signal applied to the input terminal.
Claim 2
Dependent Claim
147 words
A drive circuit for effecting current flow in an inductive circuit and comprising in combination, a power transistor having its emitter collector circuit connected in series with the inductive circuit, an input transistor for supplying base drive to the power transistor, an input terminal to the drive circuit, the base of said input transistor being connected to said input terminal so as to receive an input signal therefrom, a resistor connected in the emitter collector circuit of said power transistor and across which is developed a signal representative of the current flowing in the inductive circuit, and negative feedback means controlled by the signal developed across said resistor for opposing change in the input signal applied to the base of the input transistor whereby the mean value of current flowing in the inductive circuit will depend upon the magnitude of a signal applied to the input terminal.
Claim 3
Dependent Claim
43 words
A drive circuit as claimed in claim 1 in which the negative feedback means conTrolled by said signal comprises a feedback transistor arranged to provide a current supply to the base of the input transistor which opposes the action of the input signal.
Claim 4
Dependent Claim
22 words
A drive circuit as claimed in claim 2 in which the emitter of the feedback transistor includes a resistor in series therewith.
Claim 5
Dependent Claim
37 words
A drive circuit as claimed in claim 3 in which a positive feedback path is provided between the power transistor and the input transistor whereby the power transistor and the input transistor operate in the switching mode.
Claim 6
Dependent Claim
23 words
A drive circuit as claimed in claim 4 in which said positive feedback path is connected to the base of the input transistor.
Claim 7
Dependent Claim
22 words
A drive circuit as claimed in claim 5 including means for controlling the rate of change of current in the power transistor.
Claim 8
Dependent Claim
33 words
A drive circuit as claimed in claim 6 in which said means for controlling the rate of change of current comprises a capacitor connected between the base and collector of the input transistor.
Claim 9
Dependent Claim
32 words
A drive circuit as claimed in claim 5 including a diode through which the base of said feedback transistor is supplied with the signal representing the current flow in the actuator coil.
Claim 10
Dependent Claim
52 words
A drive circuit as claimed in claim 1 in which the inductive circuit comprises an actuator coil which forms part of an actuator for a control member of an internal combustion engine, said input transistor being supplied with a signal indicative of the force required to be exerted on the control member.
References Cited (Backward Citations)
US3037130A
Cited
US3704382A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-03-04 | 1977-09-03 | 1978-03-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-04 | 1981-09-03 | 1982-03-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-04 | 1985-09-03 | 1986-03-05 | $7700.00 | Window Closed / Lapsed |