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:
Feb. 28, 1989
Filed:
Jan. 27, 1987
Kelvin Shih, Brighton, MI (US);
Peter A Hochstein, Troy, MI (US);
Other;
Abstract
A method and circuit for supplying power from a constantly available power source (20) to an audio power amplifier (14) for a speaker (12) utilizing input leads (16,18) having an audio signal. A pre-amplifier (24) is used for amplifying the audio signal having a difference in potential between the input leads (16,18). A switch (58) powers the audio power amplifier (14) and pre-amplifier (24) from the power source (20) in response to a control signal. The method and circuit is characterized by sensing (26) the existence of a diminished audio signal by determining a greater difference than the predetermined difference between the input leads (16,18) to produce the control signal which operates a relay driver transistor (62) which, in turn, operates a relay switch (66) to supply power to the pre-amplifier (24) and power amplifier (14).