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. 31, 1988
Filed:
Jun. 20, 1986
Wolfgang Kopke, Berlin, DE;
Robert Bosch GmbH, Stuttgart, DE;
Abstract
To provide for permanent calibration of an audiometer, for example, to hold the calibration even in case of an interruption of supply voltage, an electrically erasable programmable and reprogrammable read-only memory (EEPROM) (15) receives calibration data in a closed loop by comparing the output of a transducer (13) with the input to a measuring microphone (31), in digital form and after digitizing, with command outputs stored in a computer (22). A tone generator (11), likewise controlled by the computer, provides control frequencies via a controlled amplifier (12) to the transducer (13). The calibrating EEPROM (15) receives correction data from the computer via a data bus (29) which, in turn, controls the resistance of a switchable resistance (18, 181) to provide a correction voltage to the amplifier (12).