US 8,787,044 B2 · Energy recovery snubber circuit for power converters

Abstract

An energy recovery snubber circuit for use in switching power converters. The power converters may include a switch network coupled to a primary winding of an isolation transformer, and rectification circuitry coupled to a secondary winding of the isolation transformer. The energy recovery snubber circuit may include clamping circuitry that is operative to clamp voltage spikes and/or ringing at the rectification circuitry. The clamped voltages may be captured by an energy capture module, such as a capacitor. Further, the energy recovery snubber circuitry may include control circuitry operative to return the energy captured by the energy capture module to the input of the power converter. To maintain electrical isolation between a primary side and a secondary side of the isolation transformer, a second isolation transformer may be provided to return the captured energy back to the input of the power converter.

Claims21

Dependent claims

An energy recovery snubber circuit for use in a switching power converter having an input and an output, the power converter comprising a first transformer having a primary winding and a secondary winding, a controllable switch coupled to the primary winding, and rectification circuitry coupled to the secondary winding, the energy recovery snubber circuit comprising:

a voltage clamping element coupled to the rectification circuitry;
a capacitive element coupled to the voltage clamping element for storing energy captured by the voltage clamping element;
a second transformer having a primary winding coupled to the capacitive element and a secondary winding coupled to the input of the power converter;
and
control circuitry operably connected to the rectification circuitry, wherein the rectification circuitry triggers the control circuitry to, independent of the amount of energy stored by the capacitive element, selectively cause energy stored by the capacitive element to transfer to the input of the power converter via the second transformer.

2 more elements

Dependencies are inferred from the claim text.

Energy recovery snubber circuit for power converters

Life of this patent

Energy recovery snubber circuit for power converters

Life of this patent

Abstract

Claims21