What major and diploma do you need to design a circuit diagram that can realize a certain function?

This question you asked is not easy to answer. Generally speaking, junior college students should be able to read general circuit diagrams and designs at a higher level if they follow the educational syllabus and requirements formulated by the Ministry of Education. Undergraduate and graduate students should be able to design more.

But in fact, if you think about our current education situation, I estimate that graduate students can't design independently after graduation, or they may just be flexible about a small piece of knowledge in their own field. Think about it, how many students are very clear about the working characteristics of diodes, triodes and operational amplifiers? In addition, there are MOSFET circuit, power amplifier circuit, rectifying and shaping power supply circuit, waveform generation circuit and so on. It is even more difficult to have a little comprehensive knowledge. The above is aimed at students majoring in electronic and electrical engineering.

If it is not this major, if there is no interest and no study, I think it is impossible to do design. Coupled with the progress of chip technology and the actual situation of the project, very few people can really understand this set. To tell the truth, I'm not afraid of your jokes. I have studied the automatic control of strong current and weak current, that is, I am engaged in related majors. Maybe I'm stupid. I haven't started for 2 years. It takes six years to look at the system circuit diagram and connect the lines back and forth. Of course, our circuit diagram is a little more complicated. For this picture, some careless comrades who have worked for more than ten years can't explain it to me flexibly and often need to consult relevant materials. Because many people are molded products, they only know how to use them and don't know how to design them. I can probably describe our circuit diagram to you. This is a servo control system. First of all, we need to know something about motor and mechanical transmission. Who knows the transfer function of the motor? Don't turn over the books now, it's rare. Secondly, its control circuit, position control, speed control and torque control form its own closed-loop system. Who will calculate in frequency domain? Then the thyristor rectifier circuit, who will realize it, including sawtooth wave generation, pulse generation and bridge circuit, who will draw the circuit in one breath. This is the framework, including power generation, protection logic implementation, chip selection, actual heat dissipation considerations and so on. Maybe the principle is right, but it always fails to work. Who will analyze it with principle? Not much, really. So I personally think that the real design needs practical work experience and engineering accumulation, not what the textbook says. We intend to improve our own control system and explain the principle clearly first, but in actual operation, we find that the book is full of block diagrams, and no one knows how to realize it. What can we do? We can only stand on the shoulders of giants, buy similar products first, learn, learn from and understand everything, then imitate and transform. This is our way. Fantasy can't produce products, and it can't produce results. So Confucius said: "I often think all day, it is better to learn what I have learned in a short time." It is also said that "it is not bad to study from time to time (when practicing)." A student can't acquire design ability without his own practice. I think so!