Reaearch on the precise measuring circuit of ULF voltage
SONG E-nuo, LIU Yuan-yi, DONG Cui-lian(Heilongjiang Institute of Science and Technology,Harbin 150027,China)
The paper introduces the precise measuring circuit of ultra-low frequency voltage based on the characteristics of the measurement of ULF. The circuit can measure and disply the effective value and frequency of the voltage. The single-chip microcomputer is the core of the system. The paper narrates the structure and work theory of the system.