To reduce a measurement error caused by a parasitic capacity existing in a semiconductor element constituting a voltage measuring circuit, and to heighten furthermore measuring speed, without requiring an expensive high-capacity capacitor.
This voltage measuring device has a charging circuit 100 having semiconductor elements P1, P2 of the first switch group for dividing a plurality of voltage sources Vcn connected in series into a plurality of blocks and connecting the voltage of each block to a charging capacitor Cn, and semiconductor elements N3, N4 of the second switch group for connecting a block voltage accumulated in the charging capacitor Cn to an output terminal; and an A/D converter 120 and a CPU 130 connected to an output terminal of the charging circuit 100. The CPU measures beforehand a floating capacity including the parasitic capacity of the semiconductor element N4, calculates an error voltage caused by the charge accumulated in the floating capacity, and calculates a true value of the voltage of each block by subtracting the calculated value of the error voltage from a measured value of a terminal voltage of the output terminal of the charging circuit 100.
AIZAWA KAZUYA
Iwa Saki Kokuni
Akira Kurihara
Kawamata Sumio
Masakazu Ito
Shunichi Takahashi
Toshio Takamatsu
Next Patent: PARTICLE MEASURING DEVICE