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. 14, 1981
Filed:
Oct. 15, 1979
Joseph W Erker, Aurora, OH (US);
Ohio Nuclear, Inc., Solon, OH (US);
Abstract
The current amplifier with automatic drift correction is designed for use in conjunction with computerized tomographic scanners or other apparatus. The amplifier comprises a differential amplifier with a first input connected to a photodiode or other source of current to be amplified. An integrating amplifier is connected between the differential amplifier output and a second differential amplifier input. The integrating amplifier has a time constant which is long compared with the period during which the diode current is to be amplified to provide automatic drift correction. A feedback loop connects the output of the differential amplifier with the first differential amplifier input. The feedback loop comprises a pair of matched transistors interconnected to form a current mirror. A first resistor connects the current mirror with ground. Current flow through these two resistors is summed to form the current flow received by the current mirror. The mirror current generated by the current mirror forms the amplifier output signal.