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:
Apr. 10, 1990
Filed:
Apr. 03, 1989
Harald Stader, Munich, DE;
Hans W Rudolf, Munich, DE;
Siemens Aktiengesellschaft, Berlin and Munich, DE;
Abstract
An apparatus for separating dc current and ac current signal portions of a composite signal. The apparatus has a main current path for carrying the composite signal. This path splits into a dc current path and into two dc blocked ac current paths. At the node a virtual ground potential for the ac current signal portions is generated with the aid of an inverting amplifier with negative feedback located in one of the ac current paths. Thus, only the dc current portions flow over the dc current path. In a preferred embodiment, the dc blocking is implemented by a capacitor in each ac current path, and the inverting amplifier is an operational amplifier, whose non-inverting input is at ground potential, whose inverting input is connected with the respective capacitor and whose output is connected both with the inverting input via an ohmic negative feedback resistor and with an impedance in the other ac current path.