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:
May. 24, 1994
Filed:
Jun. 09, 1993
Raphael Rahamim, Orange, CA (US);
Dale E Folwell, Placentia, CA (US);
Rockwell International Corporation, Seal Beach, CA (US);
Abstract
The ACTIVE SURGE REJECTION CIRCUIT uses a FET connected in one of the TIP and RING leads to open and close the lead. A JK flip-flop is connected to a voltage sensing circuit which senses voltage surges and clocks the flip-flop early in the voltage rise. This activates a first circuit to ground the FET gate and hold the FET open. Meanwhile, a second circuit comprising an RC circuit charges a capacitor which maintains the FET in its OFF condition for a period of time longer than the surge, i.e., about 1 m sec, and then clears the JK flip-flop after the capacitor has discharged a predetermined amount. This invention thus provides surge (noncommon mode) protection, and is especially useful in protecting modems from voltage surges while minimizing signal distortion during non-surge conditions.