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:
Mar. 12, 1996
Filed:
Jan. 28, 1994
George F Squibb, Spring, TX (US);
Compaq Computer Corp., Houston, TX (US);
Abstract
A power switch circuit including a small signal transformer and a low power oscillator for detecting the power switch while isolating it from the primary of the power supply. When the power switch is off, or is otherwise pressed to turn off the power supply, the oscillator charges a capacitor. A sensing and control circuit coupled to the oscillator and capacitor grounds a vital signal of the power supply keeping the power supply turned off. In one embodiment, when the switch is turned on, it shorts the signal transformer disabling the oscillator, so that the capacitor is discharged and the sensing and control circuit releases the vital signal. In another embodiment, the power switch momentarily disables the oscillator and discharges the capacitor, so that the sensing and control circuit toggles a flip-flop circuit to turn on the power supply.