| 摘要 |
<p>PURPOSE:To improve safety at the time of a blackout failure when a low beam goes out due to filament blowout or the like by automatically turning a high beam on by means of an electrical circuit including a reed switch, transistors, etc. CONSTITUTION:When a power source voltage is applied to a low beam 1 by means of a changeover switch 4, the low beam 1 is turned on and at the same time a low beam pilot lamp 6 is turned on by means of a reed switch 3. On the other hand, if the filament of the low beam 1 blows out, the reed switch 3 is turned off and a current flows from the base of a transistor 10 to the emitter. Due to this, the power source voltage is applied via a diode 7 and a beam attenuation resistor 8 to a high beam 2 to be lit. And when the high beam is lit, the diode 7 prevents the low beam from being lit simultaneously.</p> |
