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:
Nov. 17, 1992
Filed:
Jan. 08, 1992
Timothy W Dittmer, Quincy, IL (US);
Harris Corporation, Melbourne, FL (US);
Abstract
An AC power amplifier is disclosed for amplifying an AC input signal while limiting the current drawn by the amplifier. The amplifier includes at least one transistor having an input circuit for receiving an AC input signal as well as a DC bias voltage and an output circuit connected to the DC voltage source for drawing current therefrom during conductive periods of the transistor. The transistor exhibits the characteristic of being nonconductive when the AC input signal together with the DC bias voltage are less positive than a DC threshold voltage level and is conductive when the AC input signal and the DC bias voltage are together more positive than the DC threshold voltage level whereupon DC current is drawn by the output circuit from the DC voltage source. The DC current is sensed and a sense signal is provided having a magnitude in accordance therewith. The sense signal is compared with a reference current level and a control signal is provided having a value which varies as a function of the comparison. The control signal is decreased in magnitude when the sense current exceeds the reference current level. The DC bias voltage is then decreased to thereby decrease the conductivity of the transistor and thereby limit the magnitude of the DC current to that of the reference current level.