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US 2003/0198062 A1Published application
Switching power supply circuit
AssigneeSony Corporation
InventorMasayuki Yasumura
Life of this patent
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Abstract
The present invention relates to a circuit which includes a combination of a current resonance type converter of a switching frequency controlling system with a partial voltage resonance circuit is configured such that, in order to improve the power factor where the load power is 150 W or more and the circuit employs an input double voltage rectification system, a series resonance capacitor or inductor is connected in series to a tertiary winding wound on the primary side of an isolation converter transformer so that the voltage is fed back to a rectification circuit composed of a high speed recovery type diode.
Claims9
A switching power supply circuit comprising:
- rectification smoothing means including a rectifier and a smoothing capacitor connected in series for rectifying and smoothing an ac voltage supplied through two lines for an ac power supply;
- an isolation converter transformer including a core and a primary winding, a secondary winding and tertiary winding wound on said core for transmitting an output on a primary side obtained by said primary winding to a secondary side wherein said secondary winding is wound, said tertiary winding being provided on said primary side;
- switching means including two switching elements coupled in a half-bridge coupling for intermittently outputting an output voltage of said smoothing means to said primary winding of said isolation converter transformer;
- switching driving means for driving said switching elements to perform a switching operation;
- a current resonance circuit formed from a leakage inductance component of said primary winding of said isolation converter transformer and a capacitance of a series resonance capacitor connected in series to said primary winding for making the operation of said switching means operation of the current resonance type;
- a partial voltage resonance circuit formed from a capacitance of a parallel resonance capacitor connected in parallel to one of said switching elements and a leakage inductance component of said primary winding of said isolation converter transformer for performing a voltage resonance operation within a turnoff period of each of said switching elements;
- and
- dc output voltage production means for receiving and rectifying an alternating voltage obtained by said secondary winding of said isolation converter transformer to produce a secondary side dc output voltage,
- wherein said tertiary winding is connected between one of said two lines for the ac power supply and said smoothing capacitor.
6 more elements
A switching power supply circuit comprising:
- a rectification smoothing circuit including a voltage rectifier for rectifying ac current and a smoothing capacitor for smoothing the rectified current from said voltage rectifier;
- an isolation converter transformer including a core and a primary winding, a secondary winding and tertiary winding wound on said core for transmitting an output on a primary side obtained by said primary winding to a secondary side wherein said secondary winding is wound;
- switching means including two switching elements coupled in a half-bridge coupling for intermittently outputting an output voltage of said rectification smoothing circuit to said primary winding of said isolation converter transformer;
- switching driving means for driving said switching elements to perform a switching operation;
- a primary side series resonance circuit formed from a leakage inductance component of said primary winding of said isolation converter transformer and a capacitance of a primary side series resonance capacitor connected in series to said primary winding for making the operation of said switching means operation of the resonance type;
- a partial voltage resonance circuit formed from a capacitance of a primary side partial resonance capacitor connected in parallel to one of said switching elements and a leakage inductance component of said primary winding of said isolation converter transformer for performing a voltage resonance operation within a turnoff period of each of said switching elements;
- a power factor improving circuit including a first high speed recovery type diode element connected between said voltage rectifier and said smoothing capacitor, a series connection circuit of said tertiary winding and a second high speed recovery type diode element connected in parallel with said first high speed recovery type diode element;
- and
- dc output voltage production means for receiving and rectifying an alternating voltage obtained by said secondary winding of said isolation converter transformer to produce a secondary side dc output voltage.
6 more elements
Dependencies are inferred from the claim text.