Back to results
US 6,719,435 B2Granted
Dc-Dc converter with reduced input current ripples
AssigneeMatsushita Electric Works, Ltd.
InventorToshiaki Nakamura
Life of this patent
Estimating the term…
Abstract
An improved DC-DC converter with reduced input current ripples. The converter includes a transformer, a switch, and a capacitor. The switch turns on and off alternately to store the energy in the transformer. The capacitor is connected in series with a rectifier and a secondary winding of the transformer across an input DC voltage so as to be charged by the energy released from the secondary winding through the DC power source. Accordingly, the circuit sees an input current which continues flowing through the DC power source even the switching element is turned off.
Claims10
A DC-DC converter comprising:
- a converter input which is adapted to receive an input DC voltage;
- a converter output which is adapted to be connected to a load for providing an output DC voltage to said load;
- a switching element which is connected across said converter input and is driven to turn on and off;
- a transformer having a primary winding and a secondary winding, said primary winding being connected in series with said switching element across said converter input to induce an energy at said secondary winding in response to said switching element being turned off,
- a capacitor which is connected in circuit to be charged by said energy released from said secondary winding so as to accumulate said output DC voltage, and which is connected across said converter output to provide said output DC voltage to said load,
- wherein said capacitor is connected in series with a rectifier and said secondary winding across said converter input so as to be charged by the energy released from said secondary winding through said converter input and said rectifier,
- said secondary winding being connected in circuit with said capacitor such that said secondary winding, in response to said switching element being turned-off, releases its energy through said rectifier, said converter input, and said capacitor to charge said capacitor, and
- said secondary winding and said rectifier being connected in series across said converter output such that said secondary winding, also in response to said switching element being turned-off, releases its energy through said rectifier to provide said output DC voltage to said converter output.
5 more elements
A ballast for a discharge lamp, said ballast being a combination of a DC-DC converter and an inverter, said DC-DC converter comprising
- a converter input which is adapted to receive an input DC voltage;
- a converter output which is adapted to be connected to a load for providing an output DC voltage to said load;
- a switching element which is connected across said converter input and is driven to turn on and off;
- a transformer having a primary winding and a secondary winding, said primary winding being connected in series with said switching element across said converter input to induce an energy at said secondary winding in response to said switching element being turned off,
- a capacitor which is connected in circuit to be charged by said energy released from said secondary winding so as to accumulate said output DC voltage, and which is connected across said converter output to provide said output DC voltage to said load,
- wherein said capacitor is connected in series with a rectifier and said secondary winding across said converter input so as to be charged by the energy released from said secondary winding through said converter input and said rectifier,
- said inverter being connected to said converter output and converting said output DC voltage into an AC voltage for operating the discharge lamp,
- said secondary winding being connected in circuit with said capacitor such that said secondary winding, in response to said switching element being turned-off, releases its energy through said rectifier, said converter input, and said capacitor to charge said capacitor, and
- said secondary winding and said rectifier being connected in series across said converter output such that said secondary winding, also in response to said switching element being turned-off, releases its energy through said rectifier to provide said output DC voltage to said converter output.
6 more elements
Dependencies are inferred from the claim text.