The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 03, 2001
Filed:
Jun. 04, 1999
Tatsuo Toyonaga, Kanagawa, JP;
Yuji Kaneko, Kanagawa, JP;
Sodick Co., Ltd., Kanagawa, JP;
Abstract
A power supply device for an electric discharge machining apparatus, comprising a d.c. power source (,), a bridge circuit (,) having one pair of opposed switching circuits and the other pair of opposed switching circuits, and a controller (,) for alternately turning on either the one pair of switching circuits or the other pair of switching circuits so that high frequency a.c. voltage pulses are applied from a d.c. power source across a gap (G) formed between a workpiece (,) and a tool electrode (,). The four switching circuits (,) respectively include at least two switching transistors connected in parallel, and the controller alternately turns on the least two transistors for each of the four switching circuits.