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:
Dec. 18, 1990
Filed:
May. 25, 1989
Applicant:
Inventor:
David Gurwicz, Gateshead, GB;
Assignee:
Nada Electronics Limited, , GB;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B23H / ;
U.S. Cl.
CPC ...
219 6913 ; 219 6918 ; 323222 ; 323271 ;
Abstract
The power supply circuit has an inductor connected to a DC source through a regulating circuit arranged to maintain a constant current in the inductor. A MOSFET is connected to the inductor and to the spark gap so that when the MOSFET is conducting, current is diverted from the inductor to the spark gap. The frequency and mark-space ratio of switching of the switching device is controlled to control the machining process. A second switching device (40) is arranged to conduct when the voltage across a capacitor (34) exceeds a reference voltage. A diode (46) is used to return excess energy to the DC source.