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US 5,969,963 AGranted
Power converting device supplying AC voltage of a continuous wave form
AssigneeMatsushita Electric Works, Ltd.
InventorsMasahito Ohnishi, Hiroshi Ogasawara
Life of this patent
Estimating the term…
Abstract
A power converting device includes at least power source section providing a pulsation voltage output of a stepped waveform, and a piezo-electric element for shaping output voltage waveform of the power source section substantially into a sinusoidal waveform and boosting and dropping output voltage value of the power source section. A fundamental wave component of the piezo-electric element is transformed by a boosting and dropping element and a filter element to be applied to a load, whereby it is enabled to apply to the load a required voltage of a substantially continuous waveform, without employing any element of high withstand voltage nor decreasing power conversion efficiency.
Claims8
A power converting device comprising:
- a power source section outputting an AC voltage of a stepped waveform having a plurality of voltage levels at least at a rising part, wherein the power source section comprises
- a switched capacitor including a plurality of capacitors,
- charging switching elements inserted in a charging path from a DC power source to the capacitors,
- discharging switching elements inserted in a discharging path from the capacitors to a piezoelectric transformer,
- a control circuit rendering the output voltage waveform to be a pulsating waveform varying stepwise by controlling ON/OFF timing of the charging and discharging switching elements;
- and
- means for inverting the polarity of an output voltage of the switched capacitor in every cycle of the pulsating waveform;
- the piezoelectric transformer electrically connected to said power source section shaping the stepped waveform of the output voltage of the power source section into a substantially continuous waveform and boosting and dropping the output voltage of the power source section;
- and
- a load to which the output voltage is applied.
7 more elements
A power converting device comprising:
- a power source section for outputting an AC voltage of a stepped waveform having a plurality of voltage levels at least at rising part;
- and
- a piezo-electric transformer including a driving section formed by disposing a piezo-electric element between a pair of opposing input electrodes, and a generating section formed by providing an output electrode to the piezo-electric element as separated from the driving section by a predetermined distance, for shaping the output voltage waveform of the power source section substantially into a continuous waveform and for voltage-converting the output voltage of the power source section;
- the power source section comprising a switched capacitor including a plurality of capacitors, charging switching elements inserted in a charging path from a DC power source to the capacitors, discharging switching elements inserted in a discharging path from the capacitors to the piezo-electric transformer, and a control circuit for rendering the output voltage waveform to be a pulsating waveform varying stepwise by controlling ON/OFF timing of the charging and discharging switching elements;
- and
- means for inverting the polarity of the output voltage of the switched capacitor at every cycle of the pulsating waveform;
- the power source section having an output frequency being set substantially in conformity to a resonance frequency of the generating section of the piezo-electric transformer, and the output voltage of the power source section being applied through the piezo-electric transformer to a discharge lamp.
4 more elements
A power converting device comprising:
- a power source section for outputting an AC voltage of a stepped waveform having a plurality of voltage levels at least at rising part;
- and
- a piezo-electric transformer including a driving section formed by disposing a piezo-electric element between a pair of opposing input electrodes, and a generating section formed by providing an output electrode to the piezo-electric element as separated from the driving section by a predetermined distance, for shaping the output voltage waveform of the power source section substantially into a continuous waveform for voltage-converting the output voltage of the power source section to be appied to a load;
- the power source section comprising a switched capacitor including a plurality of capacitors, charging switching elements inserted in a charging path from a DC power source to the capacitors, discharging switching elements inserted in a discharging path from the capacitors to the piezo-electric transformer, and a control circuit for rendering the output voltage waveform to be a pulsating waveform varying stepwise by controlling ON/OFF timing of the charging and discharging switching elements;
- and
- an inverter circuit for inverting the polarity of the output voltage of the switched capacitor at every cycle of the pulsating waveform;
- the output voltage of the device being varied in the frequency component ratio of the waveform by the ON/OFF timing control by the control circuit in the switched capacitor.
4 more elements
Dependencies are inferred from the claim text.