MAGNETIC MODULATION TYPE AMPERE-TURN COMPARATOR OF COMPOSITE CONSTITUTION

摘要

PURPOSE:To increase a response speed and to improve precision and stability by using an amplifier and a DA converter that are superior in responsiveness as a compensating circuit for responsiveness in a negative feedback circuit, and synthesizing outputs to supply to a feedback winding. CONSTITUTION:The modulation output voltage of a double-frequency component generated owing to an ampere-turn difference of an input to a magnetic modulator 10 is amplified selectively by an AC amplifier 12 and a demodulation output is obtained by a synchronous detector 14. The compensating circuit 18, on the other hand, mixes a sampled value voltage, which corresponds to a current supplied to the input winding Ni of the magnetic modulator 10, as a compensation signal to the detection output of a circuit 16 to flow a feedback current to the feedback winding Nf of the magnetic modulator 10 through an amplifier 22. The DA converter superior in responsiveness is used for the circuit 18.