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. 30, 1978
Filed:
Mar. 11, 1977
Katsumi Ishikawa, Tokyo, JA;
Akio Ozawa, Tokyo, JA;
Pioneer Electronic Corporation, Tokyo, JA;
Abstract
A Schmitt trigger circuit including transistors Q12 and Q13 having a common emitter resistor R3 is thermally coupled to a power amplifier A in a monolithic IC chip, and the base of Q12 is biased at a cutoff potential under normal operating conditions. When the temperature rises to a first predetermined level V.sub.BE of Q12 drops below its biasing potential owing to the temperature characteristic of Q12, whereby Q12 conducts, which cuts off Q13 and, through transistor Q14, disables the amplifier. The common emitter feedback provides a thermal hysteresis characteristic, whereby Q12 is not cut off again until the temperature drops below a second predetermined level.