Patent ID: 8222871

Claim:
A charging device for charging an ultracapacitor ( 1 ) from a battery ( 2 ), said ultracapacitor ( 1 ) having a first nominal direct service voltage and said battery ( 2 ) having a second nominal direct service voltage lower than said first nominal direct service voltage, said charging device comprising: a reversible DC/DC converter ( 3 ) arranged between said ultracapacitor ( 1 ) and said battery ( 2 ); a stepdown voltage converter ( 4 ) arranged between said DC/DC converter ( 3 ) and said ultracapacitor ( 1 ), said stepdown voltage converter ( 4 ) formed by a first static switch ( 9 ) arranged between input and output terminals of said stepdown voltage converter ( 4 ) and by a diode ( 10 ) arranged in parallel to said output terminals of said stepdown voltage converter ( 4 ); and switching ( 11 , 12 , 9 ) and control ( 23 ) means provided for putting into service said stepdown voltage converter ( 4 ) and putting out of service said DC/DC converter ( 3 ) when a charging voltage of said ultracapacitor ( 1 ) is lower than said second nominal direct service voltage, and for putting out of service said stepdown voltage converter ( 4 ) and putting into service said DC/DC converter ( 3 ) when the charging voltage of said ultracapacitor ( 1 ) is equal to or greater than said second nominal direct service voltage; said DC/DC converter ( 3 ) comprising a first inductive resistor ( 13 ), a shunt ( 14 ), a first capacitor ( 15 ) and second and third static switches ( 11 , 12 ) both of which form a dividing bridge in parallel to said input terminals of said stepdown voltage converter ( 4 ); a mid-point of said bridge being connected to said first inductive resistor ( 13 ) in series with said shunt ( 14 ) and by said first capacitor ( 15 ) in parallel to said dividing bridge.