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:
Jul. 07, 1981
Filed:
Apr. 18, 1979
Shunichiro Mori, Koriyama, JP;
Kunio Kimata, Kyoto, JP;
Hirofumi Aoyagi, Habikino, JP;
Hiroshi Horii, Kashihara, JP;
Hidenobu Hasegawa, Kusatsu, JP;
Matsushita Electric Industrial Co., Ltd., Kadoma, JP;
Abstract
A system comprising a heat generating load such as a heater, a power control element for directly or indirectly supplying current to the heat generating load, a temperature detecting circuit for producing an ON signal when the temperature of the heat generating load is lower than a set temperature and an OFF signal when the temperature is higher than the setting, and a control circuit for feeding an ON or OFF signal to the power control element in response to the ON or OFF signal from the temperature detecting circuit. The control circuit includes a failure detecting circuit for logically comparing the signal from the temperature detecting circuit with the terminal voltage across the power control element to produce output when the power control element is in conduction although the signal from the temperature detecting circuit is an OFF signal. Upon the failure of the power control element, for example, due to self-triggering, the failure is detected directly by the failure detecting circuit and, in response to the resulting output therefrom, the power supply to the heat generating load is stopped to assure safety.