Patent ID: 6696846
Filing Date: 2004-02-24
Classification: G01R

Abstract:
A self-balanced active current bridge for measuring the impedance of an external device or an output current, comprising:an input signal source; an operation amplifier connected to said input potential source via a first input terminal of said operation amplifier; a balancing bridge coupled to a first output terminal and a second output terminal of said operation amplifier; a controlled potential source coupled to said balancing bridge and used to maintain the balance state of said balancing bridge; a resistance connected between said balancing bridge and an output terminal of said controlled potential source; wherein said external device connects a first node between said balancing bridge and a second input terminal of said operation amplifier; wherein said controlled potential source is coupled to said balancing bridge to maintain the balance state, thereby constructing the self-balanced active current bridge for measuring the impedance of said external device or the output current by means of measuring the potential variation of said resistance.