白炽灯瞬时启动电磁冲击力的研究

Study on Electromagnetic Force of Incandescent Lamp Instantaneous Startup

由于金属材料钨的电阻率与温度为正特性关系，灯丝额定工作状态时的电阻是冷态电阻的十多倍，因此启动时白炽灯的瞬时电流远大于额定工作电流。我们采用电磁动力学的方法计算了瞬时启动时灯丝螺旋线圈所受到的磁场力，并就瞬时冲击电流对灯丝寿命的影响进行了讨论。

Because the resistivity of tungstenic filament in incandescent lamp is positive dependant on the temperature,the filament resistance under operation is about eighteen times larger than those at room temperature,that means the electric current through the filament at starting stage is far greater than those in operation.Since the filament is coiled,the increase of the filament current will consequently induces a larger electromagnetic force between the coils.We calculate the electromagnetic force of incandescent lamp at start up and idscuss its effect on filament life.