Incremented Overcurrent Fault Detector Circuit
Original Publication Date: 1985-Feb-01
Included in the Prior Art Database: 2005-Feb-18
This article describes an easy-to-implement and low-cost version of an analog circuit for the detection of overcurrent fault conditions in a machine environment where the overcurrent fault may be relatively small compared to the current capacity of the affected supply voltage. With reference to the figure, amplifier A1 and resistors R1, R2, R3 and R4 comprise a differential amplifier. The inputs A01 and B01 are connected across a current shunt resistor (R shunt) such that A01 is equal to or positive with respect to the potential at B01. In this configuration the output of amplifier A1 will be a positive-going voltage level that is proportional to the magnitude of the current flow in the shunt resistor.