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:
Jan. 21, 1992
Filed:
Jun. 14, 1990
Mitsubishi Denki K.K., Tokyo, JP;
Abstract
A waveform control device for an electrical discharge machine apparatus which supplies current pulses to the gap between an electrode and a workpiece for machining of the workpiece. A first D.C. source, which supplies at least a part of a voltage that is applied across the gap, is connected in parallel with first and second circuits comprising a series connection of a switch and a diode. Connected between a first and second series circuit is a switched conductive circuit which, together with an auxiliary D.C. source, maintains the current flow at a base current level. Control of operation of the switches in the first and second circuits permit a controlled discharge of current across the gap while permitting the output voltage to be clamped at a safe level. A plurality of inductive circuits may be used to provide selectivity, where the inductances are different and to provide further control of the discharge current shape. A variable inductance, whose value is proportional to the output peak current, may be used to control current ripple.