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:
Sep. 07, 1993
Filed:
Dec. 20, 1990
Applicant:
Inventor:
Keith K Klett, Danville, IL (US);
Assignee:
Hurletron Incorporated, Danville, IL (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02H / ;
U.S. Cl.
CPC ...
361 56 ; 361 55 ;
Abstract
A gravure printing press with an electrostatic assist unit having a fault detection circuit and crowbar circuit in which the crowbar circuit has a transformer with a primary winding and a plurality of secondary windings. Each of the secondary windings has a field-effect transistor which is turned on in response to the detection of a fault condition whereby the voltage applied to the press is substantially reduced to zero and any electrostatic charge is substantially removed. A capacitor is coupled in parallel with the gate and source terminals of each field-effect transistor to lengthen the on-time of the transistors.