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:
Feb. 16, 1999
Filed:
Nov. 04, 1996
David G Pounds, Marion Center, PA (US);
FMC Corporation, Chicago, IL (US);
Abstract
An SCR firing circuit is provided which includes a plurality of opto-couplers, diodes, a capacitor and an SCR, utilized to control the AC power applied to a load, such as a vibratory feeder. In various embodiments of the invention, one or more opto-couplers act as solid state switches and also isolate a control signal from the AC line voltage. The capacitor is charged from an AC power source through the diode during a half cycle of the AC line voltage, and remains charged until the SCR is triggered. In response to a control signal rendering the opto-couplers conductive, the capacitor is discharged through the opto-couplers to fire the SCR and provide AC power to the load. A back-to-back SCR firing circuit is also provided which fires a first SCR when a line voltage is positive and which fires a second SCR when the line voltage is negative, which may be utilized to adjust the frequency of the application of power to the load independently of the frequency of the AC power supply.