我们的学校位于农村中,由于没有发电厂和其他设备来供给交流电,所以当初中物理课讲到变压器的原理的时候,往往因为没有交流电源而不可能通过演示实验使学生直观地认识变压器的原理及其应用,尤其关于升压和降压的演示。故学生所获得的知识不能深化,并且有关变压器的其他原理的解说,也由于没有交流电而感到困难。我过去曾经使用一具电铃或蜂声器以及齿轮断续器来使蓄电池的直流电变成脉冲,通过变压器的初级线圈使次级感生电流。但是由于蜂音器的振动片振动次数和手摇齿轮每秒次数很少,虽可使变压器的次级电压升高,但是功率小,在没有交流电表(指高压)设备情况下,只能用110 v、15 w的电灯泡来代替,接入次级只能使灯泡变红。怎样来改进这个缺点呢?这是我 Our school is located in rural areas, because there is no power plant and other equipment to supply AC, so when the physics class talked about the principle of the transformer, it is often impossible to demonstrate the principle of the transformer intuitively because of the absence of AC power And its applications, especially on buck and buck. Therefore, students’ acquired knowledge can not be deepened, and explanations on other principles of transformers are also troublesome due to lack of AC power. I used to use a bells or buzzer and a gear interrupter to pulse the battery’s DC to induce secondary current through the transformer’s primary coil. However, since the vibration frequency of the buzzer and the number of hand gears per second are small, the secondary voltage of the transformer can be raised but the power is small. In the absence of an ammeter, it can only be used 110 v, 15 w light bulb instead, access to the secondary only make the light bulb red. How to improve this shortcoming? This is me