Michael E Kurchak

US Patent:

48975222, Jan 30, 1990

Filed:

Feb 6, 1989

Appl. No.:

7/306470

Inventors:

Dale L. Bilczo - Rocky River OH
Larry L. Church - Jefferson OH
Michael J. Kurchak - Eastlake OH

Assignee:

The Lincoln Electric Company - Cleveland OH

International Classification:

B23K 910
H02M 3335

US Classification:

21913032

Abstract:

A control circuit is provided for the output of a high frequency inverter of the type having an output transformer with a core, primary windings and a secondary winding with two sections for creating a first secondary current pulse of electrical current in one section when the primary windings magnetizes the core and a second secondary current pulse in the other of the secondary sections when the primary windings remagnetizes the core. By alternating switch means for passing current through the primaries to magnetize and remagnetize the core at a preselected rate the output current pulses are provided by the two sections of secondary windings. The control circuit of the present invention involves a modification of the output transformer secondary stage. A first auxiliary winding is connected to one of the secondary sections to create an auxiliary current pulse as the core of the transformer is magnetized. A means is then employed for limiting this auxiliary current pulse and for adding the limited auxiliary current pulse to the first secondary pulse created by the secondary section to which the auxiliary winding is connected.