| 摘要 |
A voltage monitor circuit, wherein a high voltage is not applied to a monitor circuit even if a series circuit of plural batteries (1a, 1b, 1c and 1d) connecting a battery pack (1, 11, 21) is cut off, is provided. When a current breaking switch (3, 14) is turned off, a high series voltage with reversed polarity of plural batteries (1a, 1b, 1c and 1d) is generated across the current breaking switch (3, 14). Subsequently, a solid state switch (5a, 5b, 5c) with a negative voltage is turned off. Further, as a wire on the side of a battery pack monitor circuit (4, 24) also has a negative voltage, another solid state switch (5a, 5b, 5c) biased by a voltage of the wire is turned off likewise. Consequently, a high voltage is not generated between the wires (P1, P2, P3, P4) on the side of the battery pack monitor circuit (4, 24) even if the current breaking switch (3, 14) is turned off. |
