Accession Number : ADD012765

Title :   Analog Circuit for Simulating a Digitally Controlled Rheostat.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE AIR FORCE WASHINGTON DC

Personal Author(s) : Ott,William E

Report Date : 17 Feb 1987

Pagination or Media Count : 7

Abstract : The simulation of a two-wire rheostat is accomplished by an analog output circuit whose value is digitally controlled. It comprises a four-quadrant multiplying digital to analog converter (MDAC) and a current booster including active elements in the feedback loop of an amplifier. The digital rheostat acts as a variable resistance whose value is controlled by a digital controller and can accommodate either AC or DC excitations. The unit forms a negative feedback loop containing only solid-state devices and relies on fixed resistors for accuracy.

Descriptors :   *PATENTS, *SOLID STATE ELECTRONICS, *CONTROL SYSTEMS, *CIRCUITS, VARIABLE RESISTORS, CIRCUIT ANALYSIS, ELECTRONIC MULTIPLIERS, ELECTRICAL IMPEDANCE, ACCURACY, ANALOG SYSTEMS, DIGITAL SYSTEMS, DIGITAL TO ANALOG CONVERTERS, FEEDBACK, FIXED RESISTORS, LOOPS, OUTPUT, RESISTANCE, SIMULATION, VARIABLES

Subject Categories : Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE