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, 2019
Filed:
Jun. 28, 2018
Audio-technica Corporation, Tokyo, JP;
Satoshi Yoshino, Tokyo, JP;
Audio-Technica Corporation, Tokyo, JP;
Abstract
Provided is a condenser microphone circuit that can support variation in power supply voltage of a phantom power supply using a wiring system of two lines. A condenser microphone circuit includes a microphone unit, an FET, a constant current diode, a collector grounding first transistor that generates an operation power supply of the FET, a first resistor that sets base potential of the first transistor, a collector grounding second transistor that amplifies an output signal from the FET, a second resistor that sets base potential of the second transistor, and an output circuit. A base of the first transistor is connected to a source of the FET, an emitter of the first transistor is connected to a drain of the FET, a base of the second transistor is connected to the drain of the FET, an emitter of the second transistor is connected to the output circuit, and the second resistor divides voltage on a cathode side of the constant current diode.