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:
Apr. 23, 1996
Filed:
Aug. 01, 1994
Gunars Briedis, Milwaukee, WI (US);
Jerome K Hastings, Sussex, WI (US);
Michael R Scharnick, Brookfield, WI (US);
Eaton Corporation, Cleveland, OH (US);
Abstract
A contactor has an armature, a pull-in coil and a holding coil. When the system is energized through a first switch such as a thermostat, the low current holding coil is energized in preparation for holding the armature pulled in after the pull-in coil is energized and the armature has finished its power stroke. A solid-state switching device and the pull-in coil are connected in series between both terminals of a power source. A control circuit causes the solid-state switching device to be conductive the instant power is supplied to the circuit through the first switch. One embodiment of the control circuit is based on logic gates. RC circuits associated with the gates keep the solid-state switching device and pull-in coil conducting long enough for the armature to pull-in. After the solid-state switching device turns on, the transistor is controlled to turn off, deenergizing the pull-in coil while the holding coil holds the armature in until the first switch opens and power input is discontinued. Another embodiment, based on a programmable timer, delivers current pulses to the pull-in coil at uniform periodicity until the armature is pulled in. After the armature is pulled in, pulse signals are shunted from the solid-state switching device so it turns off, and current pulses through the pull-in coil are discontinued, while the holding coil holds the armature in pulled-in condition until the first switch is opened.