EP0297708A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Resonant inverter system and circuit for controlling the resonant inverter system
Assignee: Spellman High Voltage Electronics Corp
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Filing: 1988-05-11
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Granted: —
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Expires: 2008-05-11
Abstract
Abstract An inverter system has first and second resonating current sources (50-63, 70-83) which are resonant at the same frequency. The currents of the two sources are combined. At lower power levels, the currents are substantially out of phase and the frequency is adjusted. At intermediate power levels, the phases of the currents are adjusted and the frequency is fixed. At high power levels, the currents are substantially in phase and the frequency is adjusted.
Inventors
- 👤 Derek Chambers
- 👤 Andrzej Bortkiewicz
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 01:14
CPC Classifications
H; H02; H02M; H02M3/00; H02M3/22; H02M3/24; H02M3/28; H02M3/305; H02M3/315; H02M3/3155
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
102 words
An inverter system comprising an input for connection to a DC power source and a first resonating current source, characterized by comprising a second resonating current source (70-83) resonant at the same frequency as the first current source (50-63), means for combining the currents in the first and second current sources (50-63, 70-83), and control means (68) responsive to variation of the combined currents from a selected value for adjusting the frequency of operation of the first and second current sources (50-63, 70-83) and the relative phases thereof in directions which tend to cause the combined currents to approach the selected value.
Claim 2
Dependent Claim
102 words
An inverter system comprising an input for connection to a DC power source and a first resonating current source, characterized by comprising a second resonating current source (70-83) resonant at the same frequency as the first current source (50-63), means for combining the currents in the first and second current sources (50-63, 70-83), and control means (68) responsive to variation of the combined currents from a selected value for adjusting the frequency of operation of the first and second current sources (50-63, 70-83) and the relative phases thereof in directions which tend to cause the combined currents to approach the selected value.
Claim 3
Dependent Claim
44 words
An inverter system as claimed in claim 1, characterized in that the control means (68) is arranged to operate in a plurality of distinct modes in respective power ranges and to adjust, in each of the modes, either the frequency or the relative phases.
Claim 4
Dependent Claim
36 words
An inverter system as claimed in claim 1 or 2, characterized in that, at low power levels, the control means (68) causes the currents to be substantially out of phase and the frequency to be adjusted.
Claim 5
Dependent Claim
36 words
An inverter system as claimed in any one of the preceding claims, characterized in that, at intermediate power levels, the control means (68) causes the frequency to remain fixed and the relative phases to be adjusted.
Claim 6
Dependent Claim
74 words
An inverter system as claimed in claim 4, characterized in that, at intermediate power levels, the control means (68) normally adjusts the relative phases in a continuous manner but, in response to the power level reaching a predetermined value, causes a substantial discrete step change in the relative phases, the predetermined value being such that the power level is substantially the same for the relative phases before and after the step change takes place.
Claim 7
Dependent Claim
36 words
An inverter system as claimed in any one of the preceding claims, characterized in that, at higher power levels, the control means (68) causes the relative phases to remain fixed and the frequency to be adjusted.
Claim 8
Dependent Claim
27 words
An inverter system as claimed in claim 6, characterized in that, at higher power levels, the control means (68) causes the currents to be substantially in phase.
Claim 9
Dependent Claim
78 words
An inverter system as claimed in any one of the preceding claims, characterized in that the control means (68) includes first means (100, 101) for adjusting the frequency of operation, second means (110-116) for adjusting the relative phases, means (107) for representing the magnitude of the difference between the combined currents and the selected value, and non-linear circuit means (108) responsive to the representing means (107) to switch control between the first and second means (100, 101; 110-116).
Claim 10
Dependent Claim
22 words
An inverter system as claimed in claim 8, characterized in that the non-linear circuit means (108) has a continuous smooth transfer characteristic.
Claim 11
Dependent Claim
21 words
An inverter system as claimed in claim 9, characterized in that the non-linear circuit means (108) operates in an analog fashion.
Claim 12
Dependent Claim
117 words
A circuit for controlling the signal outputs of a pulse width modulator integrated circuit to exhibit phase and frequency changes which are both functions of an input signal but which change over respective input signal sub-ranges, with only one of the phase and frequency changing over each input signal sub-range, comprising a pulse width modulator integrated circuit having error amplifier input means and a current control input, characterized by further comprising resistor means (100) connected to the current control input (6), Zener diode means (108) having a cathode connected to the current control input (6) and an anode connected to the error amplifier input means (114), and means (105-107) for coupling an input signal to the anode.
Claim 13
Dependent Claim
117 words
A circuit for controlling the signal outputs of a pulse width modulator integrated circuit to exhibit phase and frequency changes which are both functions of an input signal but which change over respective input signal sub-ranges, with only one of the phase and frequency changing over each input signal sub-range, comprising a pulse width modulator integrated circuit having error amplifier input means and a current control input, characterized by further comprising resistor means (100) connected to the current control input (6), Zener diode means (108) having a cathode connected to the current control input (6) and an anode connected to the error amplifier input means (114), and means (105-107) for coupling an input signal to the anode.
Claim 14
Dependent Claim
60 words
A circuit as claimed in claim 11, characterized in that the means (105-107) is arranged to provide the input signal with an overall range with three sub-ranges such that, in the lowest and highest sub-ranges, the signal outputs exhibit frequency changes but not phase changes and, in the middle sub-range, the signal outputs exhibit phase changes but not frequency changes.
References Cited (Backward Citations)
FR2215743A1
Cited
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