Power Integrations, Inc.
Methods and apparatus for biasing a magnetic circuit to reduce audible noise from a switching power supply

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Abstract:

Presented herein are methods and apparatus for biasing magnetic circuits to reduce audible noise from a switching power supply. A magnetic component (e.g., a magnet) is constructed and provided to a core (e.g., a ferromagnetic core) to offset (i.e., bias) an applied magnetomotive force. By selecting and/or manufacturing the magnetic component based on a circuit operating condition, the offset may be tailored to advantageously shift a frequency of mechanical deformation outside the audible noise range. In a switching power supply with fixed peak current, the offset to the applied magnetomotive force may be determined, at least in part, by the fixed peak.

Status:
Grant
Type:

Utility

Filling date:

18 Mar 2020

Issue date:

15 Feb 2022