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. 02, 1986
Filed:
Dec. 21, 1984
John D Harnden, Jr, Schenectady, NY (US);
William P Kornrumpf, Albany, NY (US);
George A Farrall, Rexford, NY (US);
General Electric Company, Schenectady, NY (US);
Abstract
Zero crossing synchronous AC switching circuits are provided which employ piezoelectric ceramic bender-type switching devices for use in supplying loads of a resistive, inductive or capacitive nature. The circuits include zero crossing sensing sub-circuits for sensing the passage through zero value of a supply source of alternating current voltage and/or current and for deriving zero crossing timing signals representative of the occurrance of the zero crossings. The zero crossing timing signals are employed to control operation of a bender energizing potential control sub-circuit for selectively controlling application or removal of a bender energizing potential across the piezoelectric bender member of the bender-type switching devices. Phase shift networks are included in the circuit for shifting the phase or time of application of the selectively applied bender energization potential so as to cause it to close or open a set of load current carrying switch contacts substantially at or near the naturally occurring zero crossings of the applied alternating current supplying the load.