| 摘要 |
<p>PURPOSE:To prolong the life of head light lamps by connecting filaments in the head lamps between the collectors and emitters of large capacity transistor in series, and by applying turn-on and off control signals to the bases. CONSTITUTION:When a switch 8 is turned so as to deenergize a controller 9, the controller 9 delivers a suitable voltage to a series circuit composed of a resistor 11 or 12 connected between the base and emitter of a transistor 4 or 5 so that a predetermined current runs through the base of the transistor. Accordingly, a predetermined current corresponding to the base current runs through filaments 21, 31 connected to the collector of the above-mentioned transistor so as to turn on lamps 2, 3. That is, even during the initial stage of turn-on during which the resistances of the filaments 21, 31 are extremely low, and the filament currents are restricted by the transistors 4, 5 so that it is not raised exceeding a predetermined value, thereby it is possible to prevent breakage of the filaments 21, 31.</p> |
