| 摘要 |
PROBLEM TO BE SOLVED: To provide a switch box for surely detecting an open failure or a short circuit failure in each of switching transistors connected in parallel.SOLUTION: The switch box includes: a pair of switching transistors connected in series to connect a pair of cells in parallel; a pair of diodes respectively connected to the pair of switching transistors in parallel and connected to an anode terminal in common; an individual driving circuit for individually performing ON/OFF operation of the pair of switching transistors; and a driving circuit which when turning on either one of the pair of switching transistors, sets a drive voltage to be applied to a control terminal of the one switching transistor to be turned on so that a voltage of a node of the pair of switching transistors becomes a voltage capable of preventing flow of a current to a cell of the switching transistor in OFF operation through the diode.SELECTED DRAWING: Figure 2 |
