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. 04, 1987
Filed:
Nov. 14, 1986
Bruce A Heaston, West Milton, OH (US);
General Motors Corporation, Detroit, MI (US);
Abstract
A power latch circuit uses first and second bipolar transistors responsive to an actuate voltage to latch into a conductive state with power supplied to a computer and a third bipolar transistor powered by the latch circuit and responsive to a deactivate voltage from the computer to place the first and second transistors in a deactivated state to remove power from the computer and itself. It further uses an FET in parallel with the third bipolar transistor and activated directly from the DC power supply when the second transistor is deactivated to latch the first and second transistors in the deactivated state in spite of voltage fluctuations on the deactivate line which might otherwise cause the latch circuit to reactivate. As an FET, it uses little current through its gate compared to alternative bipolar devices while the latch circuit is deactivated.