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:
Aug. 13, 2002
Filed:
Mar. 01, 2001
Hideo Hashimoto, Saitama, JP;
Takeshi Uchida, Saitama, JP;
Nihon Dempa Kogyo Co., Ltd., Tokyo, JP;
Abstract
An oven-controlled oscillator includes a thermostatic oven having a heat source, a vibrator provided in the thermostatic oven, an oscillation circuit for generating an oscillation signal in response to an action of the vibrator, and a heat source control circuit. The heat source control circuit includes a sensor for detecting an internal temperature of the thermostatic oven, an operational amplifier for controlling current to flow through the heat source in response to a resistance value of the sensor so that the internal temperature of the thermostatic oven may be maintained at a predetermined preset temperature, and a feedback resistor for the operational amplifier. The feedback resistor includes a thermistor whose resistance value drops as the temperature rises, and the thermistor is thermally coupled to the thermostatic oven. Preferably, a quartz-crystal element is used as the vibrator.