一、车灯警告器 汽车在断开点火开关而忘记关车灯时,车灯警告器能发出警报,提醒驾驶员关灯。 警告器的主电路是由一只2N217晶体管组成的电感反馈低频振荡器(图1)。当双刀双掷开关K倒向“正常”位置时,点火系的电源(正极)与晶体管的集电极相通,车灯系的电源(正极)经二极管1N34与发射极相通。这时集电极与发射极电位相同,振荡器不工作。 First, the lights alarm Car off the ignition switch and forget the lights, the lights warning lights to alert drivers to turn off the lights. The main circuit of the alarm is an inductive feedback low frequency oscillator consisting of a 2N217 transistor (Figure 1). When the double-pole double-throw switch K is turned to “normal” position, the power supply of the ignition system (positive) is connected to the collector of the transistor, and the power supply (positive) of the lamp system is connected to the emitter through the diode 1N34. At this moment collector and emitter potentials are the same, the oscillator does not work.