| 摘要 |
PURPOSE:To obtain a specific gravity sensor which is stable and accurate for a long period of time by connecting the Pb electrode to the negative electrode terminal of the cell which is at least the second cell from the central cell having the specific gravity sensor, on the negative electrode terminal side of the group of the cells, and also by connecting the PbO2 electrode to the positive electrode terminal of the cell which is at least the second cell from the central cell in the opposite direction. CONSTITUTION:The terminal of PbO2 electrode is connected to the cell terminal of the cell which is at least the second cell on the positive terminal side of the group of the cells, via a diode 5 for prevention of discharge and also via a resistance 6. On the other hand, the pb electrode is connected to the PbO2 electrode of either one of cells placed on the negative terminal side of the group of the cells in the same manner. Accordingly, a specific gravity sensor 4 is charged by the battery consisting of the group of cells 1. The terminal voltage of the specific gravity sensor 4 is connected, by changeover switch 8, to the measuring device 7 which, in turn, is connected to the charger 2 through a control circuit. Then, the charging circuit to the specific gravity sensor 4 becomes open and the polarization of each electrode of the specific gravity sensor due to the charging current is dissipated. |
