Patent Number: 6,295,213

Title: Circuit for efficiently clamping a power converter's reset voltage and for providing auxiliary power

Abstract: In a power converter whose power is supplied by an input power source, a circuit is disclosed for efficiently clamping the peak reset voltage across a primary switch of the power converter and for recycling the energy stored in the clamp during the OFF period of the switch back to the input power source via a second converter through the operation of a plurality of switching transistors in the second converter. The reset energy of the power transformer in the power converter can also be coupled to an auxiliary power circuit via a winding of a transformer in the second converter. The second converter can thus provide auxiliary or stand-by power to maintain the operation of critical system circuits, when the power converter is turned off, e.g., to conserve power, such as in the sleep mode of a portable PC.

Inventors: Smith; David Anthony (Cummer Hill, GB)

Assignee: Astec International Limited

International Classification: H02M 3/24 (20060101); H02M 3/335 (20060101); H02M 003/315 (); H02M 007/122 ()

Expiration Date: 09/25/2018