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. 27, 1976
Filed:
Nov. 13, 1974
Kouichi Sekiguchi, Asaka, JA;
Abstract
A two tone generator using switching transistors in two LC resonance circuits each composed of a coil and a capacitor for producing a multifrequency signal in the form of two-tone signal by switching the value of the inductances of the coils in response to the control of push-button switches, in which only one make contact is actuated in response to the depression of each push button, so that the ON-OFF output of the contact is employed to control selected ones of switching transistors in each of the two resonance circuits for determining the oscillation frequencies of a two-tone oscillator associated with the two LC resonance circuits. The switching transistors comprises a first group of either NPN transistors or PNP transistors and a second group of NPN transistors or PNP transistors. The switching transistors are coupled with the two LC resonance circuits to switch the value of the inductance of each coil in response to the turning ON of the collector-emitter path thereof. Each of the switching transistors is turned-ON by flowing a base current more than the peak value of the AC signal developed in the resonance circuit without flowing any DC current in the collector-emitter path thereof.