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. 03, 1977
Filed:
Jul. 02, 1975
Robert R Podowski, Elmhurst, IL (US);
Richard W Citta, Oak Park, IL (US);
Zenith Radio Corporation, Glenview, IL (US);
Abstract
An electronic remote control transmitter employs a two transistor cascade oscillator having positive and negative feedback loops. The oscillator voltage is supplied through a switch assembly containing a plurality of momentary contact switches to a pair of voltage dividers supplying signal voltages in predetermined ratios to a two branch circuit in the negative feedback loop. One branch contains an inductor and the second branch a capacitor. Closure of any switch completes the DC circuits for the transistors. Signal voltage is supplied to the branches to produce a minimum amplitude, zero phase shift condition which establishes oscillation at that predetermined frequency. The output of the oscillator is amplified by a third transistor and supplied to an ultrasonic transducer for generating acoustical control signals.