AUTOMATIC BALANCE CIRCUIT FOR IMPEDANCE MEASUREMENT, ADJUSTING METHOD FOR IT AND DETECTION RESISTANCE MEASURING METHOD OF THE AUTOMATIC BALANCE CIRCUIT

摘要

PROBLEM TO BE SOLVED: To easily obtain a balance state by digital control.;SOLUTION: A second oscillator 106 having the same oscillation frequency is provided on the signal detection side separately from a first oscillator 101 of a signal applying side. Three different phase angles are sequentially set to the second oscillator from the CPU 109, and at each phase angle, voltage appearing the L terminal side is measured to obtain the phase angle θ min as a first establishment factor in the balance state by a specified first computing expression. The phase angle of the second oscillator 106 is fixed to θ min and then the amplitude of the second oscillator 106 is sequentially set to two different amplitudes. The voltage appearing on the L terminal side at every amplitude is measured to obtain an amplitude B min as a second establishment factor in the balance state by a specified second computing expression. The amplitude of the second oscillator 106 is B min.;COPYRIGHT: (C)2003,JPO