摘要 |
PURPOSE:To detect the breakage of a wire for each lamp by setting only one among a number of driving means for controlling the lighting of a number of warning lamps into OFF-state and detecting the potential on the grounded side of each lamp through a common line. CONSTITUTION:Each one edge of a number of warning lamps L1-Ln is connected with an Ig line 1 and applied with a battery voltage, and the outer edge is connected with the collectors of a number of transistors T1-Tn as shift means. The other edges of the warning lamps L1-Ln are connected wit one common line 2 through a number of diodes D1-Dn in parallel to the transistors T1-Tn. A CPU 3 sets only one among the transistors T1-Tn into OFF state, and operates as detecting means for detecting the potential which is outputted from the warning lamps L1-Ln corresponding to the transistor in OFF-state into the common line 2. |