| 摘要 |
<p>PURPOSE:To detect the filament open circuit of a winker without consuming the wasteful electric power by detecting the open circuit of multiple lamps in response to the rising speed of the charged voltage generated by the charging of a capacitor when a switching element is turned off. CONSTITUTION:When one of the filaments of a winker 11L is broken, the current fed to a capacitor 21 is decreased, thus the rising speed of the voltage across the capacitor 21 is made smaller than that prior to the open circuit, the time interval after a transistor 19 is turned off until the voltage across the capacitor 21 reaches the reference voltage Vr, i.e., the time width of the high-level pulse from an AND circuit 25, is made longer, thus the count value C of a counter 27 is made larger than the reference value Cr. Accordingly, the output level of a comparing circuit 30 becomes a high level, a transfer switch 17 is driven, the first oscillation signal from an oscillator 15 is relayed to the base of the transistor 19, the transistor 19 is turned on or off in response to the first oscillation signal, the flash frequency of the other winker is increased, and the open circuit of one of the filaments of the lamp 11, is informed to a driver.</p> |
