High-frequency resonant power converter

• US 4,823,249 A
• Filed: 04/27/1987
• Issued: 04/18/1989
• Est. Priority Date: 04/27/1987
• Status: Expired due to Term

• Current Assignee: American Telephone & Telegraph Company (AT&T, Inc.), Bell Telephone Laboratories, Inc. (Nokia Corporation)
• Original Assignee: American Telephone & Telegraph Company (AT&T, Inc.)
• Inventors: Garcia, John D. II
• Primary Examiner(s): Salce, Patrick R.
• Assistant Examiner(s): KINCAID, KRISTINE LYNN
• Application Number:
  US07/043,008
• Time in Patent Office: 722 Days
• Field of Search: 363/17, 363/22, 363/23, 363/24, 363/25, 363/26, 363/47, 363/48, 363/98, 363/126, 363/133, 363/134, 363/16
• US Class Current: 363/48
• CPC Class Codes: H02M 1/44 Circuits or arrangements for compensating for electromagnetic interference in converters or inverters
• CPC Class Codes: H02M 3/3376 with automatic control of output voltage or current
• 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

A high frequency DC to DC converter having at least two phase differentiated pulsed voltage sources, utilizes two phase differentiated unidirectional power flow resonant circuits to permit multiple quasi resonant operation of the converter and thereby gain the benefit of lowered EMI, high efficiency, lowered component stress and increased power throughput.

Claims

1. A power converter comprising:

input means for accepting a dc voltage source,

a power transformer including a primary winding and a secondary winding;

a resonating capacitor having first and second access terminals;

a first switch for applying the dc voltage source to the primary winding in a first direction;

a second switch for applying the dc voltage source to the primary winding in a second direction opposite the first direction;

a first secondary resonant circuit connected to a first terminal of the secondary winding and including, a first inductance derived in part from a leakage inductance of the transformer, a first rectifying diode and a connection to the first access terminal of the resonating capacitor;

a second secondary resonant circuit connected to a second terminal of the secondary winding and including a second inductance derived in part from a leakage inductance of the transformer, a second rectifying diode and a connection to said first access of the resonating capacitor;

the resonating capacitor having resonant operation with both the first and second resonant circuits; and

output means connected to the resonating capacitor, having constant current sink characteristics and adapted for accepting a load to be energized.

2. A power converter as defined in claim 1 wherein the first and second switch connect a first node of the input means to opposite terminals of the primary winding respectively and a second node of the input means connected to a node of the primary winding intermediate the opposite terminals of the primary winding.

3. A power converter as defined in claim 1 wherein the first and second switch are connected in a series connection and the series connection being connected in parallel across the input means.

4. A power converter as defined in claim 1 where the first and second switches are connected in a bridge configuration with a third switch connected in the bridge configuration operating in accord with the first switch and a fourth switch connected in the bridge configuration operating in accord with the second switch.

5. A power converter as defined in claim 1 and further including regulation control circuitry, comprising:

means for sensing an output signal of the load

means responsive to the means for sensing for generating an error signal responsive to a deviation of the output signal from a predetermined regulation value, and

means for converting the error signal into a frequency, and

means responsive to the frequency to generate a driver signal having a fixed interval value and a variable period, and

means for alternately applying the drive signal to the first and second switches.

6. A power converter comprising

inverting means for generating first and second voltage pulses in phase opposition to one another,

output circuitry including signal shaping circuitry, filter circuitry and output terminals to accept a load,

the signal shaping circuitry including first and second resonant circuits, resonant at a switching frequency of the inverting means, each resonant circuit including inductive impedance and a rectifying diode for limiting resonant flow through the inductive impedance to one direction of flow,

a common resonant capacitor shared by the first and second resonant circuits and having one of its terminals connected to both the first and second circuits respectively.

7. A power converter as defined in claim 6 wherein the inventing means is embodied in a push-pull configuration.

8. A power conversion as directed in claim 6 wherein the inventing means is embodied in a half bridge configuration.

9. A power converter as defined in claim 6 wherein the inventing means is embodied in a full bridge configuration.