一、电学“黑箱”的种类电学“黑箱”可分为纯电阻黑箱、纯电源黑箱、由电源和电阻组成的黑箱、含电容器和二极管的黑箱等.二、具体的操作步骤1.用电压表来判断黑箱内的电源连接情况①若有的接线柱之间的电压为0,有的接线柱之间存在恒定的电压且不为0,则说明黑箱内有电源;②若2 1. Types of “black boxes” for electricity The “black boxes” for electricity can be divided into pure resistance black boxes, pure power supply black boxes, black boxes composed of power supplies and resistors, black boxes containing capacitors and diodes, etc. II. Specific operation steps 1. Using voltmeters To judge the power connection in the black box 1 If the voltage between the terminals is 0, and there is a constant voltage between some terminals and it is not 0, there is power in the black box; 2 if 2