论文部分内容阅读
中学物理教科书一般都采用示教电流表来显示电感线圈和电容器组成的LC振荡电路的电流.要使LC振荡电路中振荡电流使电表指针的左右偏转跟电表自由阻尼振动有明显的区别,LC振荡电路的周期T_振必须远大于或远小于电表指针的固有周期T_振固·据LC振荡电路的周期T_振=2π LC~(1/2)可知,若使T_振>>T_固必须选用合适的数值较大的电感线圈和电容器,中学不易办到.若使,T_振<<时,应采用电感量较小的电感线圈和电容量较小的电容器,在这种情况下仍不易看到表针左右摆动的现象,其原因有两点:其一,是由于表针的惯性,这跟直流电表无法测交流电流相似;其二,是LC选用过小,电路中初始能量过小,表针来不及偏转已将能量耗尽,所以看不到表针的左右
Middle school physics textbooks generally use teaching electric current meter to display the current of the LC oscillating circuit composed of inductor coil and capacitor. To make the left and right deflections of the meter pointer in the LC oscillating circuit make a significant difference with the free damping oscillation of the meter, the LC oscillating circuit The period T_vibration must be much greater or much smaller than the natural period of the meter pointer T_vibration. According to the period of the LC oscillation circuit T_vibration=2π LC~(1/2), the T_vibration>>T_ The solid must use suitable inductors and capacitors with relatively large values. It is not easy to do this in high schools. If T_, please use inductors with smaller inductance and capacitors with smaller capacitance, in this case Still not easy to see the phenomenon of the left and right hands, there are two reasons: First, due to the inertia of the hands, which is similar to DC current meter can not measure AC current; Second, the LC is too small, the initial energy in the circuit Small, too late to deflect the needle has exhausted energy, so I can’t see the left and right hands