Professor Wang Limin's footsteps were a little anxious, after all, it was late today.

As a professor, he has a lot of work, imparting knowledge is only one of the aspects, he still has his own scientific research work to do, today was originally the weekend, is the time to solve the exercises agreed with the students, but it, because of the delay in scientific research, when I looked at the watch, I found that the time had already passed, so I hurried over.

Who knows, before entering the door of the classroom, he heard Bai Jiuming's words, and immediately felt a little stunned.

Someone from outside? Say you're wrong?

Halfway home?

For the latter sentence, he agrees with some of them, yes, he is a halfway monk.

The establishment of electronics is not long, it is a breakthrough in this century, and it is not as historical precipitation as other technologies, and at the same time, it also means that it is a discipline that continues to innovate and develop.

When Wang Limin was in school, there were only analog circuits, and it was mainly the era of using electron tubes, and when he went to the Soviet Union to study, he began to come into contact with the knowledge of transistors.

The whole country, in terms of electronics, almost all has only the basis of analog circuits.

However, the times are constantly developing and progressing, digital circuits, in these years of rapid development, the country is also starting from scratch, a few years ago, Wang Limin purchased a few books on digital circuits at his own expense, began to learn by himself, but also self-taught.

As a result, by last year, the first year of the official college entrance examination to select talents, at the same time, colleges and universities have officially resumed teaching, and the Institute of Technology has made some improvements and added some courses.

This digital circuit is an additional course, after all, this is to follow the trend of the world, universities, is to cultivate talents, must be in line with the world, in this regard, can not be left behind.

However, after opening it, I found that I couldn't find a teacher at all! The only people in China who are proficient in digital circuit technology have been hired by other universities, especially colleges and universities like Tsinghua University, and the School of Technology cannot compete at all.

Therefore, he is also teaching in his first year, and he encountered some problems, which was also in his expectations, and now, when he heard Bai Jiuming say that someone questioned his teaching, his face did not have the slightest dissatisfaction after his authority was questioned, and after the initial stunned, a smile appeared on his face: "Oh? Is it? Who is it? ”

As he spoke, he had already walked to the door of the classroom, and then he saw under the podium, it was his proud student Wang Xiaoyu, this child, the score in the exam was the highest, but that was only because there were a lot of points in foreign languages, and the real science knowledge was not even solid, and she also chose her current major, which is not suitable for a girl like her, but Wang Xiaoyu was not discouraged, and she has been studying seriously, which makes Professor Wang Limin very satisfied.

And next to her, there were several people, two men and one woman, one of whom had a special temperament, which immediately attracted his attention.

"That's him, that's him." Bai Jiuming was full of joy at this time, Professor Wang came too timely, I want to test you, if you don't accept the offer, then let Professor Wang test you! Hmph, now it's up to you to get off the stage!

If it was someone else, Bai Jiuming might save face for the other party, but now it is Qin Zhenhua, an existence like a rival in love who can only talk about it, of course he wants to press Qin Zhenhua to death.

"Professor Wang, look at the blackboard, he just said that the circuit diagram you drew is a snake and erased part of the circuit." Bai Jiuming continued.

He wasn't lying, that's what Qin Zhenhua said, so he was very proud, now, look at how Qin Zhenhua denies it.

At this time, Wang Xiaoyu's heart was a little flustered, biting her lip with her teeth, wanting to explain something, but she felt that it was difficult to say, for fear that if she said something wrong, she would hurt Qin Zhenhua's heart again, so she would not come to herself in the future.

"Oh?" When he saw this circuit diagram, Wang Limin's eyes suddenly lit up.

In this era, university education is not particularly standardized, there is no higher authorities to review and issue all kinds of teaching materials, especially this newly opened discipline, it can be said that everything is to feel the stones to cross the river, handouts, that is Wang Limin carved steel plate wax paper during the holiday, and then took it to print, directly used as a textbook, of course, this is also from the materials he bought at his own expense, collected and sorted out, quite a lot of effort.

As for this circuit diagram, Wang Limin remembers very well that in his information, it is the way it is now, erasing the other parts, leaving a rather concise part.

However, he always felt that this was a blind eye, he could only see the part, and he didn't know how it worked, so in order to deepen his understanding, he used the precipitated knowledge of the original analog circuit to supplement it, and when he lectured, he also focused on it, and there was a sense of complacency at that time.

But now, he was erased by the other party, saying that he had added to the snake, and he was not annoyed, but was full of excitement about the thirst for knowledge.

"Tell me, young man, why aren't those important?" Wang Limin said to Qin Zhenhua.

Bai Jiuming was on the side, and his heart was happy, okay, look, our Professor Wang has come to teach you, see what else you can say!

Wang Xiaoyu nervously pinched the corner of her clothes, this, how will Brother Zhenhua explain? Don't hurt your peace.

After all, on one side is Brother Zhenhua, who thinks about him day and night, and on the other side, there is a highly respected and respected professor.

"Professor Wang, what kind of class is this?" No one expected that Qin Zhenhua would actually start asking Professor Wang!

"Digital circuits." Wang Limin was asked rhetorically, and he didn't have too much dissatisfaction, so he replied directly: "Abbreviated as digital electricity, the previous analog circuit, referred to as modular electricity." ”

"Yes, Professor Wang, this is a digital circuit!" Qin Zhenhua pointed to the blackboard and said: "In digital circuits, all variables are reduced to two opposing states: 0 and 1. This can be expressed in terms of the presence or absence of a signal, the high or low level, the switching on or off, and so on, and we only care about its state, not the detailed value of a variable. For example, a small change in the amplitude of the level can be meaningless. ”

"But what about you? You've spent half a day here just to tell you how electricity flows? This, we don't need to know, we only know, whether it is 0 or 1 when it goes in, and 0 or 1 when it comes out, and that's enough, and the rest is mixed in, which is meaningless, and will cause extreme chaos. Qin Zhenhua shook his head helplessly: "Digital electricity is digital electricity, and modular electricity is analog electricity, even if you talk about AD and DA conversion (analog electricity digital electricity conversion), it can't be mixed!" ”

When he said this, there was already a tone of hatred for iron and steel, this teaching is a mess, and it is misleading.