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:
Oct. 01, 1985
Filed:
Sep. 19, 1983
Dennis J Loring, Pawtucket, RI (US);
Elmwood Sensors, Inc., Pawtucket, RI (US);
Abstract
A magnetically operated AC switching device, such as an AC electrical contactor, is operable with a delay-on-dropout feature to permit safe shutdown of equipment energized therethrough in case of power failure. The device includes an AC pickup winding which is energizable from an AC power source and a DC holding winding which is electrically connected to a rectifier for energization of the holding winding with DC power from the AC source. A capacitor is also electrically connected to the rectifier in parallel with the holding winding for energization with DC power from the AC source. Upon energization of the device, the AC pickup winding moves fixed and movable contacts of the device into engagement, and the DC holding winding maintains them in engagement. The AC pickup winding can remain energized without burnout; and upon power dropout the capacitor supplies DC power to the holding winding for an instant to provide a slight delay in the separation of the contacts.