Pp. Bey et al., STABILITY ANALYSIS OF AN AUTONULLING AC BRIDGE FOR USE WITH SILICON-BASED SENSORS, IEEE transactions on circuits and systems. 1, Fundamental theory andapplications, 41(3), 1994, pp. 210-239
A novel circuit incorporating integral feedback to automatically null
an ac bridge is analyzed and discussed. Stability of the feedback sche
me is examined by linearizing the system near the critical point (null
) of the bridge using a standard perturbation method. Solutions of the
nonlinear coupled differential equations that describe the operation
of the autonulling ac bridge were obtained by numerical integration. A
prototype was constructed using integrated circuits and discrete comp
onents to measure the transient response; test results of the circuit
from transient impedance changes are compared to the time-dependent nu
merical solutions.