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:
Aug. 11, 1992
Filed:
Jul. 13, 1990
Steve Dumbovic, Elmhurst, IL (US);
Illinois Tool Works Inc., Glenview, IL (US);
Abstract
A solid state switch is provided which has the capability of retaining its last state memory in the event of a power failure or interruption. The solid state switch includes an output driver formed of at least one N-channel MOS field-effect transistor, a holding capacitor, a charging resistor, a transistor-connected diode interconnected between a power supply voltage source and the charging resistor for preventing leakage of the holding capacitor. The field-effect transistor has its drain connected to a first output terminal and it source connected to a second output terminal. One end of the holding capacitor is connected to the gate of the field-effect transistor and its other end is connected to a ground potential. The holding capacitor retains the last state between the first and second output terminals in the event of a loss of the power supply voltage source.