US3662216A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Alternating current power modulator with parallel lc circuit controlling the relative phase of voltage and current applied to switching means
Assignee: General Electric Co
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Filing: 1970-06-18
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Granted: 1972-05-09
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Expires: 1990-06-18
Abstract
Abstract A gated, bilateral switch is coupled between a resonant power supply and an alternating current load. A detuned, parallelconnected LC circuit is connected across the switch to control the phase difference between current and voltage applied to the switch and assure commutation. In the absence of triggering signals applied to the switch, the LC current provides a first, low level of energy to the load. A zero-voltage crossover at the alternating switch gates the switch at the beginning of alternate half cycles. Power is modulated in response to a logic circuit which alternately enables and disables the zero-voltage crossover switch at a selectable frequency and a selectable duty cycle.
Inventors
- 👤 Andy M Hildebrant
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:28
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/13; H03K17/136; H05; H05B; H05B41/00; H05B41/14; H05B41/30
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
110 words
In an alternating current circuit for supplying power from an alternating current input waveform source and a resonant input circuit to a load and including, gated bilateral switching means for providing conduction paths in opposite directions in series between the source and the load, the improvements comprising: a parallel LC circuit connected across said switching means, said parallel LC circuit providing a predetermined phase relationship between the current and the voltage applied to said parallel LC circuit at a predetermined time of each half cycle of the input waveform, whereby said LC circuit forms a resonant circuit responsive to the alternating current input waveform and provides a current path therefor.
Claim 2
Dependent Claim
110 words
In an alternating current circuit for supplying power from an alternating current input waveform source and a resonant input circuit to a load and including, gated bilateral switching means for providing conduction paths in opposite directions in series between the source and the load, the improvements comprising: a parallel LC circuit connected across said switching means, said parallel LC circuit providing a predetermined phase relationship between the current and the voltage applied to said parallel LC circuit at a predetermined time of each half cycle of the input waveform, whereby said LC circuit forms a resonant circuit responsive to the alternating current input waveform and provides a current path therefor.
Claim 3
Dependent Claim
50 words
The improvement according to claim 1 in which the values of the components of said parallel LC circuit are chosen to provide a substantially zero phase difference between current and voltage applied to said switching means when the input voltage waveform is in the immediate vicinity of its zero-voltage crossover.
Claim 4
Dependent Claim
29 words
The improvement according to claim 2 wherein said parallel LC circuit includes a saturable reactor having a value such that it operates near the knee of its hysteris loop.
Claim 5
Dependent Claim
26 words
The improvement according to claim 3 wherein said parallel LC circuit includes a resistor connected in series with a capacitor for dampening said parallel LC circuit.
Claim 6
Dependent Claim
105 words
In an alternating current system for providing alternating current power from a resonant LC circuit supplied by an input source waveform to a non-linear load, a modulator circuit for connection between said input circuit and said load comprising: gated bilateral switching means coupled between the source and the load, and a parallel LC circuit connected across said switching means, said parallel LC circuit providing a substantially zero phase relationship between voltage and current applied to said switching means when said switching means is gated, whereby said LC circuit forms a resonant circuit responsive to the alternating current input waveform and provides a current path therefor.
Claim 7
Dependent Claim
105 words
In an alternating current system for providing alternating current power from a resonant LC circuit supplied by an input source waveform to a non-linear load, a modulator circuit for connection between said input circuit and said load comprising: gated bilateral switching means coupled between the source and the load, and a parallel LC circuit connected across said switching means, said parallel LC circuit providing a substantially zero phase relationship between voltage and current applied to said switching means when said switching means is gated, whereby said LC circuit forms a resonant circuit responsive to the alternating current input waveform and provides a current path therefor.
Claim 8
Dependent Claim
25 words
The modulator circuit according to claim 5 in which said switching means comprises first and second oppositely poled, parallel connected amplifying gate silicon controlled rectifiers.
Claim 9
Dependent Claim
94 words
The modulator circuit according to claim 6 further comprising a zero-voltage crossover switch having first inputs coupled to be responsive to the source input waveform and for providing gating signals to said silicon controlled rectifiers, first and second outputs respectively coupled for selectively gating said first and second silicon controlled rectifiers, and a further input coupled to a source of modulation frequency, said source of modulation frequency being coupled to enable said zero voltage crossover switch to provide gating signals when the output of said source of modulation frequency is of a first polarity.
Claim 10
Dependent Claim
29 words
The modulator circuit according to claim 7 wherein said source of modulation frequency comprises an asymmetrical square wave generator having a selectable frequency and a selectable degree of asymmetry.
Claim 11
Dependent Claim
16 words
The modulator circuit according to claim 8 wherein said parallel LC circuit includes a saturAble reactor.
Claim 12
Dependent Claim
49 words
The modulator circuit according to claim 9 in which said parallel LC circuit includes a resistor connected in series with said capacitor, said resistor dampening said parallel LC circuit and forming in combination with said capacitor an RC circuit for controlling dv/dt across said silicon controlled rectifiers upon turn-off.
Claim 13
Dependent Claim
123 words
An alternating current system comprising in combination: a. an input LC circuit for connection to a source of an alternating current voltage input waveform and having first and second terminals; b. gated, bilateral switching means connected in series with a first terminal of said input LC circuit; c. a parallel LC circuit connected across said gated bilateral switching means, said parallel LC circuit providing a substantially zero phase difference of voltage and current applied to said bidirectional switching means when said bidirectional switching means is gated and providing a current path when said bidirectional switching means is not gated; and d. an alternating current load circuit connected in series between said parallel LC circuit and a second terminal of said input LC circuit.
Claim 14
Dependent Claim
123 words
An alternating current system comprising in combination: a. an input LC circuit for connection to a source of an alternating current voltage input waveform and having first and second terminals; b. gated, bilateral switching means connected in series with a first terminal of said input LC circuit; c. a parallel LC circuit connected across said gated bilateral switching means, said parallel LC circuit providing a substantially zero phase difference of voltage and current applied to said bidirectional switching means when said bidirectional switching means is gated and providing a current path when said bidirectional switching means is not gated; and d. an alternating current load circuit connected in series between said parallel LC circuit and a second terminal of said input LC circuit.
Claim 15
Dependent Claim
27 words
The system according to claim 11 in which said gated, bilateral switching means comprises first and second silicon controlled rectifiers oppositely poled and connected in parallel relationship.
Claim 16
Dependent Claim
107 words
The system according to claim 12 further comprising a zero-voltage crossover switch having first and second output terminals respectively connected to the gates of said first and second silicon controlled rectifiers, first and second input terminals coupled for sensing the input voltage waveform, said circuit being for producing gating signals when the input voltage waveform crosses a zero-voltage level, and further input terminals for connection to a source of modulation frequency, said zero-voltage crossover switch including means for providing successive gating signals in succession to said first and said second silicon controlled rectifiers alternately when said circuit is enabled during the provision of a modulating input wave.
Claim 17
Dependent Claim
57 words
The system according to claim 13 further comprises a modulation frequency source being coupled to said zero-voltage crossover switch for enabling the provision of gating signals when the output of said modulation frequency source is of a first polarity, said modulation frequency source providing a selectable frequency and a selectable degree of asymmetry of modulation frequency waveform.
Claim 18
Dependent Claim
18 words
The system according to claim 14 in which said silicon controlled rectifiers comprise amplifying gate silicon controlled rectifiers.
Claim 19
Dependent Claim
22 words
The system according to claim 15 in which said load circuit comprises a saturable reactor connected in series with a discharge lamp.
Claim 20
Dependent Claim
16 words
The system according to claim 16 in which said parallel LC circuit includes a saturable reactor.
Claim 21
Dependent Claim
28 words
The system according to claim 17 in which said parallel LC circuit includes a capacitor connected in series with a resistor, said resistor dampening said parallel LC circuit.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-09 | 1975-11-08 | 1976-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-09 | 1979-11-08 | 1980-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-09 | 1983-11-08 | 1984-05-09 | $7700.00 | Window Closed / Lapsed |