Computer power supply

• US 6,930,895 B2
• Filed: 10/02/2003
• Issued: 08/16/2005
• Est. Priority Date: 11/01/2002
• Status: Expired due to Fees

• Current Assignee: Nipron Co., Ltd.
• Original Assignee: Nipron Co., Ltd.
• Inventors: Tatsumi, Akira, Yamada, Tomiji
• Primary Examiner(s): Patel, Rajnikant B.
• Application Number:
  US10/676,047
• Publication Number:
  US 20040085054A1
• Time in Patent Office: 684 Days
• Field of Search: 363 2112- 2118, 363/89, 363/72, 363/732, 363/81, 323/222, 323/282, 323/272, 323/207
• US Class Current: 363/21.18
• CPC Class Codes: H02M 1/0048 Circuits or arrangements for reducing losses using snubbers H02M1/34
• CPC Class Codes: H02M 3/33561 having more than one ouput with independent control
• CPC Class Codes: H02M 3/33576 having at least one active switching element at the secondary side of an isolation transformer
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

An object of the present invention is to provide a computer power supply in which, by improving the circuit itself, internal heat loss can be reduced, thereby greatly improving efficiency. A partial resonance circuit 8 is constituted by a primary side winding N1 of a high frequency transformer 3, a resonance condenser 7, and two switching elements Q1, Q2, a secondary side output circuit 4 for driving a load is connected to a secondary side of the high frequency transformer 3 via a winding, and a reverse converter 11 for driving and halting the first switching element and second switching element by causing the respective phases thereof to differ on the basis of a driving signal is provided.

Claims

1. A computer power supply wherein a first switching element and a second switching element operating with a DC voltage as an input are disposed on the primary side of a high-frequency transformer, said first switching element is connected to one end of a primary side winding of said high-frequency transformer, and said second switching element is connected to the same end of the primary side winding as the connection side of said first switching element via a resonance condenser and in a state of differing polarity to said first switching element, said primary side winding, resonance condenser, and two switching elements constituting a partial resonance circuit, a secondary side output circuit for driving a load is connected to the secondary side of said high-frequency transformer via a winding, a first driving circuit and a second driving circuit having a delay element are provided for driving and halting said first switching element and second switching element on the basis of a driving signal by causing the respective phases thereof to differ, and a reverse converter is provided for supplying to the input portion of one of said driving circuits insulation from the other of said driving circuits and a reverse input voltage.

2. The computer power supply according to claim 1, wherein said reverse converter is disposed about an iron core such that the primary side winding and secondary side winding have differing polarities.

3. The computer power supply according to claim 1, wherein a magnetic amplifier having a dead angle is provided in said secondary side output circuit or a magnetic snubber is provided in a synchronous rectifier circuit.

4. The computer power supply according to claim 1, wherein said primary side winding end and an earth side end of at least one of said switching elements are connected in series via two condensers having differing capacitance, and a diode is connected in parallel to the condenser with the smaller capacitance.

5. The computer power supply according to claim 1, wherein two auxiliary windings, which are different to an output winding provided on the secondary side of said high-frequency transformer, are disposed on said secondary side;

two synchronous rectifier driving circuits for transferring the output from the primary side to said two auxiliary windings with little loss are connected to the two auxiliary windings respectively in a state of differing polarities; and

switching elements for said two synchronous rectifier driving circuits are provided, which are bestowed with an ON-OFF signal synchronously with the secondary voltage of said high-frequency transformer.

6. The computer power supply according to claim 1, wherein two resistors for determining the ON periods of said first switching element and second switching element are connected to a PWM control circuit for outputting said driving signal so as to be parallel when a comparator for controlling the ON periods of said first switching element and second switching element is ON.