Patent ID: 6522249
Filing Date: 2003-02-18
Classification: G01D,H04B,H04Q

Abstract:
An interface that provides selected information from a sensor mechanism to a utilization mechanism over a two-wire connection, power for the interface and the sensor mechanism being received from the utilization mechanism over the two-wire connection, the interface comprising:a switch circuit connected between first and second wires of the two-wire connection, the switch circuit providing a high impedance between the first and second wires when open and a low impedance between the first and second wires when closed, switch circuit state being selectively controlled by the sensor mechanism, current flow through the switch circuit being sensed by the utilization mechanism as indicative of the selected information from the sensor mechanism; a voltage regulator that provides a selected voltage to at least selected components of the interface and the sensor mechanism; and a current regulator, operative at least when the switch circuit is open, that regulates output current provided to the voltage regulator from the first and second wires to below a predetermined level.