I was lucky enough to get the EE self-study manual. After I got it, the color of the text gave me a sense of weight.For the improvement section, the content is commonly used in work:These contents are
The following figure is a screenshot from "Northwest Model King" - a constant current source circuit composed of an op amp.Figure 1 is the original figure, the output current Io=2.5/(1/40+1/R1);Figure