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:
Jul. 08, 1980
Filed:
Oct. 16, 1978
Duane R Bolgiano, Bala Cynwyd, PA (US);
Joel M Benjamin, Jr, Pottstown, PA (US);
Victor Meyer, Jr, Telford, PA (US);
International Mobile Machines Incorporated, Bala Cynwyd, PA (US);
Abstract
A tone detector comprising a non-linear or saturated system that is adapted to receive an input frequency or group of frequencies and to provide an output in the form of turn-on and turn-off signals which are independent of the amplitude of the input, the turn-on and turn-off signals being determined by the presence or absence of a particular frequency or group of frequencies; the system including a transistor connected to a biasing network that is DC referenced to a supply voltage potential of the collector of the transistor and AC referenced to the emitter of the transistor, and a filter connected to the transistor, the filter being substitutable by an input coupling capacitor to determine the presence or absence of the particular frequency or frequencies.