Accession Number : ADD017849
Title : Balanced, Double-Sided Calibration Circuit for Sensor Element and Differential Preamplifier.
Descriptive Note : Patent, Filed 7 Oct 94, patented 19 Dec 95,
Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC
Personal Author(s) : Hagerty, James D
Report Date : 19 Dec 1995
Pagination or Media Count : 8
Abstract : The balanced, bi-directional calibration circuit of the present invention is joined to a sensor and a differential preamplifier. The sensor has two outputs which are received by the differential preamplifier such that common mode line noise is rejected. The calibration circuit includes a broadband signal generator which provides the calibration signal. The calibration circuit also includes a switching network that allows the calibration signal to be switched to either of the two sensor outputs or isolated from the sensor and preamplifier. A dual state switching control signal is applied via a single control wire to the switching network to select which preamplifier input receives the calibration signal. The calibration signal generator control line is electrically isolated from the preamplifier by an optoisolator. The electrical balance of the bidirectional calibration circuit and electrical isolation of the calibration signal generator preserve the common mode noise rejection of the differential preamplifier.
Descriptors : *LOW NOISE AMPLIFIERS, *PATENTS, *SWITCHING CIRCUITS, INPUT, CONTROL, DETECTORS, PREAMPLIFIERS, BROADBAND, BALANCE, CALIBRATION, ELECTRICAL NETWORKS, REJECTION, CIRCUIT ANALYSIS, SIGNAL GENERATORS
Subject Categories : Electrical and Electronic Equipment
Distribution Statement : APPROVED FOR PUBLIC RELEASE