Method and apparatus for driving capacitive-type load
AssigneesNippondenso Co., Ltd., Nippon Soken, Inc.
InventorsYasuyuki Sakakibara, Toshihiko Igashira, Kiyonori Sekiguchi, Masahiro Takigawa, Yoshimi Natsume
Life of this patent
Estimating the term…
Abstract
A method and apparatus for driving a capacitive-type load using a direct current power source, a charging circuit connected in series to the load, a discharging circuit connected in parallel to the load, and an electric circuit for controlling the charging and discharging circuits, and wherein at least one of the charging and discharging circuits has a primary coil, and a secondary coil coupled to the primary coil restores energy, generated when the charging or discharging is turned OFF, to the power source. This provides a highly efficient driving by a restoration of energy.
Claims15
A method for driving a capacitive-type load in an apparatus including a direct current power source;
- a capacitive-type load expanding and contracting when charged and discharged, respectively;
- a charging circuit having a first coil and a first switching element which are connected in series with said capacitive-type load from said direct current power source;
- a discharging circuit having a second coil and a second switching element which are connected in parallel with said capacitive-type load;
- a third coil electromagnetically coupled with at least one of said first coil and said second coil;
- and a third switching element provided in series with said third coil and said direct current power source;
- comprising the following steps of:
- closing the switching element connected to the coil electromagnetically coupled with said third coil and flowing electric current therethrough to that coil;
- opening the switching element closed by said closing step before the electric current flowing therethrough becomes zero;
- and
- closing said third switching element and restoring fly-back energy which is generated at the coil when the switching element is opened by said opening step, to said direct current power source through said third coil and said third switching element.
An apparatus for driving a capacitive-type load comprising:
- a direct current power source;
- a capacitive-type load which expands and contracts when charged and discharged, respectively;
- a charging circuit connected in series with said power source and said capacitive-type load for charging said capacitive-type load by a direct current from said power source;
- a discharging circuit connected in parallel with said capacitive-type load for discharging same;
- at least one of said charging circuit and said discharging circuit including a primary coil and a switching element connected in series;
- an electric circuit connected to said switching element for controlling a turning ON and OFF of said switching element;
- a secondary coil electromagnetically coupled with said primary coil and connected to said power source for restoring to said power source fly-back energy generated when said switching element is turned OFF by said electric circuit.
Dependencies are inferred from the claim text.