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:
Sep. 05, 1989
Filed:
Mar. 30, 1988
Applicant:
Inventor:
Thomas H Tichy, Albuquerque, NM (US);
Assignee:
Other;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03G / ; H04R / ;
U.S. Cl.
CPC ...
381 55 ; 381 59 ; 381111 ; 3302 / ;
Abstract
A preferred embodiment of a thermal protection circuit for a piezoelectric speaker includes a PTC resistor connected in series with the speaker and a second PTC nonlinear resistive element, such as a light bulb, connected in parallel with the resistor. This protects the speaker from failure due to overheating caused by excessive drive signals without causing audio distortion during infrequent excessive drive signals of a short duration.