US3829794A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit for reducing the direct current component of an alternating current output signal
Assignee: LAMBDA ELECTRONICS CORP
•
Filing: 1972-11-30
•
Granted: 1974-08-13
•
Expires: 1992-11-30
Abstract
Abstract A feedback arrangement for removing the net direct current component from the output transformer of an inverter due to an unbalanced volt-time characteristic of the output signal, wherein a direct current signal is used to adjust the respective conduction periods of the inverter switching devices. A portion of the total output signal in the primary of the output transformer is sampled by small resistors and filtered to derive an essentially direct current signal that excites an auxiliary winding magnetically coupled to the core of a saturable input transformer so as to change the core operating point and thereby to alter the switching control signal in a manner tending to reduce the direct current component of the output signal.
Inventors
- 👤 G Gautherin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:44
CPC Classifications
H; H02; H02M; H02M7/00; H02M7/42; H02M7/44; H02M7/48; H02M7/53; H02M7/537; H02M7/5383; H02M7/53846; H02M7/53862
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
122 words
In an electrical inverter circuit having an outut transformer including a primary winding, an input transformer excited by an output signal appearing at the output transformer to provide a drive signal, and switching means for connecting the output transformer to a direct current source in response to the drive signal: means responsive to the net direct current component of the output signal in the primary winding of the output transformer, resulting from a volt-time unbalance of said output signal, for developing a control signal; and means for applying the control signal to the input transformer to vary the drive signal so as to regulate the conduction of the switching means in a manner reducing the direct current component of the output signal.
Claim 2
Dependent Claim
122 words
In an electrical inverter circuit having an outut transformer including a primary winding, an input transformer excited by an output signal appearing at the output transformer to provide a drive signal, and switching means for connecting the output transformer to a direct current source in response to the drive signal: means responsive to the net direct current component of the output signal in the primary winding of the output transformer, resulting from a volt-time unbalance of said output signal, for developing a control signal; and means for applying the control signal to the input transformer to vary the drive signal so as to regulate the conduction of the switching means in a manner reducing the direct current component of the output signal.
Claim 3
Dependent Claim
33 words
The electrical inverter circuit of claim 1, wherein: the control signal is a direct current signal; output the applying means comprises a winding on the input transformer operative to bias the input transformer.
Claim 4
Dependent Claim
50 words
The electrical inverter circuit of claim 2, wherein: the input transformer has a core of magnetic material that is saturable in response to the exciting output signal; and the bias varies the values of the respective flux excursions, due to the exciting signal, required to saturate the core with flux.
Claim 5
Dependent Claim
70 words
The electrical inverter circuit of claim 1, wherein: the output transformer includes first and second primary windings: the switching means is connected to provide a pair of alternately conducting series loops including the respective windings and each loop including the direct current source; and the responsive means includes a resistive element in series with each primary winding for sampling a portion of the output signal developed at the primary windings.
Claim 6
Dependent Claim
24 words
The electrical inverter circuit of claim 4, wherein: the responsive means further includes means for averaging the signal portion sampled by the resistive elements.
Claim 7
Dependent Claim
35 words
The electrical inverter circuit of claim 5, wherein: the averaging means comprises an electrical inductance; and the applying means comprises a control winding on the input transformer connected to receive the averaged signal from inductance.
Claim 8
Dependent Claim
111 words
An electronic oscillator circuit of the type including an output transformer, an input transformer excited by the output signal at the output transformer, and a pair of alternately conducting switching devices driven by the input transformer to connect a direct current source to the output transformer, the improvement comprising: a control winding associated with the input transformer to generate a bias flux therein in response to a control signal applied thereto; and means responsive to the output signal for developing a control signal for application to the control winding, said control signal representing the net direct current component of the output signal due to an unbalance in the volt-time characteristic thereof.
Claim 9
Dependent Claim
111 words
An electronic oscillator circuit of the type including an output transformer, an input transformer excited by the output signal at the output transformer, and a pair of alternately conducting switching devices driven by the input transformer to connect a direct current source to the output transformer, the improvement comprising: a control winding associated with the input transformer to generate a bias flux therein in response to a control signal applied thereto; and means responsive to the output signal for developing a control signal for application to the control winding, said control signal representing the net direct current component of the output signal due to an unbalance in the volt-time characteristic thereof.
Claim 10
Dependent Claim
31 words
The electronic oscillator of claim 7, wherein: the control signal developing means includes means for sampling at least a portion of the output signal and means for averaging such sampled portion.
Claim 11
Dependent Claim
58 words
The electronic oscillator circuit of claim 8, wherein: the sampling means includes at least one resistive element connected in series with the output transformer; and the control signal developing means includes means for connecting the resistive element in a current loop including the control winding, and an inductive element in such series loop for averaging the current therethrough.
Claim 12
Dependent Claim
43 words
The electronic oscillator circuit of claim 9, wherein: the transformer includes first and second primary windings connected in a respective current loop with one of the switching devices; and a resistive sampling element is connected in series with each of the primary windings.
Claim 13
Dependent Claim
20 words
The electronic oscillator of claim 10, wherein: each resistive element is connected in a series loop with the control winding.
Claim 14
Dependent Claim
69 words
The electronic oscillator circuit of claim 8, wherein: the input transformer has a magnetic core that is saturable and a pair of secondary windings each connected to a respective switching device to apply a drive signal to each thereof; and the control signal varies the operating point of the saturable core whereby the duty cycle of each drive signal is varied in response to variations in the control signal.
Claim 15
Dependent Claim
59 words
The oscillator circuit of claim 7, wherein the output transformer is connected in a series path with each of the switching devices, the circuit further comprising: a direct current source including rectifier means having output terminals connected to at least two capacitors connected in series and having a center common terminal connected to one side of the output transformer.
Claim 16
Dependent Claim
40 words
The oscillator circuit of claim 13, further comprising: means for establishing a reference potential; and means for connecting the control winding so as to respond to the potential difference between the reference potential and the potential at the common terminal.
Claim 17
Dependent Claim
39 words
The oscillator circuit of claim 13, further comprising: an impedance connected in series with the output transformer for developing a signal related to the net direct current component therein, the control winding being connected to respond to such signal.
Claim 18
Dependent Claim
63 words
The oscillator circuit of claim 14, further comprising: first and second impedances providing a voltage dividing network connected across the direct current source and having an intermediate circuit point providing the reference potential, one side of the control winding being connected to such point and the other side of the control winding being coupled to the capacitor common terminal in a bridge circuit.
References Cited (Backward Citations)
US2861237A
Cited
US2874293A
Cited
US3146406A
Cited
US3134948A
Cited
US3145348A
Cited
US3161837A
Cited
US3219906A
Cited
US3219907A
Cited
US3308397A
Cited
US3373334A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-08-12 | 1978-02-11 | 1978-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-12 | 1982-02-11 | 1982-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-12 | 1986-02-11 | 1986-08-13 | $7700.00 | Window Closed / Lapsed |