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. 06, 1982
Filed:
Apr. 07, 1980
Robert Boudault, Limours, FR;
Gerard Pouzoullic, Gif Zur Yvette, FR;
U.S. Philips Corporation, New York, NY (US);
Abstract
The frequency shift modulator comprises an operational amplifier connected so as to form an integrating circuit and followed by a bistable circuit having trigger hysteresis for producing a two-level voltage which is applied to one end of a first resistor whose other end is coupled to an input of the operational amplifier. Logic means are provided for applying a voltage equal or complementary to the said two-level voltage, depending upon the level of the data signal, to one end of a second resistor whose other end is joined with the said other end of the first resistor. Further logic means are provided for applying a voltage equal or complementary to the said two-level voltage, depending on whether the desired modulated signal has either the one or the other central frequency, to one end of a third resistor whose other end is joined with the joined ends of the first and second resistors. Finally, a common resistor is connected between the joined ends of the three above-mentioned resistors and the input of the operational amplifier.