Resonant forward converter

• US 4,788,634 A
• Filed: 06/22/1987
• Issued: 11/29/1988
• Est. Priority Date: 06/22/1987
• Status: Expired due to Fees

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Casey, Leo F., Schlecht, Martin F.
• Primary Examiner(s): Salce, Patrick R.
• Assistant Examiner(s): Ault, Anita M.
• Application Number:
  US07/065,016
• Time in Patent Office: 526 Days
• Field of Search: 363/20, 363/21, 363/47, 363/48, 363/75, 363/131, 323/266
• US Class Current: 363/21.03
• CPC Class Codes: H02M 3/01 Resonant DC/DC converters
• CPC Class Codes: H02M 3/33538 of the forward type H02M3/3353, H02M3/33569 take precedence
• CPC Class Codes: H02M 3/33569 having several active switching elements H02M3/3353 takes precedence
• CPC Class Codes: H02M 3/3374 with preregulator, e.g. current injected push-pull
• 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 resonant forward converter at a switching frequency of 10 MHz provides a small volume point-of-load converter for distributed power systems. The leakage inductance of a transformer is made negligibly small relative to the magnetizing inductance of the transformer. This enables a resonant controllable switch on the primary side of a transformer and a secondary side rectified diode to be switched either on or off at the same time. The capacitance across the primary side switch and the secondary side diode rings with a resonant inductor connected in parallel with the transformer. Both the switch and diode, therefore, have zero voltage switching transitions. Further, the resonant inductor being connected in parallel with the transformer provides a resonant ring that is independent of load.

Claims