Sister Doudou clicked the mouse again, and quickly opened various folders, which was dazzling, just looking at all kinds of things jumping around on the screen, and I didn't know what I was looking for.

Lu Jiaren had a bitter gourd face, he had been waiting for ten minutes, and he couldn't understand what she was doing at all, so he reminded: "Senior sister! ”

Sister Doudou looked at the computer screen for a while, and even took a copy of "Motor Dragging" from the desk to quickly find the catalog, flip through it, then scan from top to bottom, flip through the catalog again, and then look at Han Jiaren blankly, "Oh, junior brother, what's the matter?" ”

Lu Jiaren is about to cry, I really want to say, sister, your acting skills are definitely powerful, what about my information?

Liu Ze looked at him embarrassed like this, and said: "Didn't Mr. Lin say just now, the model research of the communication between the fan pitch system and the main control, the pitch system is to change the windward angle of the fan, and the main control is the control of the generator. ”

"Okay, if you don't understand, you can ask me." Sister Doudou replied very seriously, her eyes were still looking at the scientific and technological literature on the computer screen, and occasionally flipped through the book next to her, as if she was verifying.

Liu Ze is such a cold person, he can't hold back and wants to burst into laughter, Sister Doudou, are you funny? The mess of documents on the screen doesn't match the book in your hand.

"Okay, I'll go back and search." Lu Jiaren said helplessly.

Successfully sent him away and kept the "top secret" information, Sister Doudou's interest also increased, she is the group flower of this research group (there is no way to be a woman), and said with a smile: "Gao Bo, Liang Shen, Huang Jin, the junior brother is here, you don't get up to say hello, people are big bulls, and they start to work on papers as soon as they come in." ”

It's a bit ridiculous and sarcastic.

Lu Jiaren also took the opportunity to say hello to them, "Senior Brother Gao is good, Senior Brother Liang is good, Senior Brother Huang is good." ”

Liu Ze also politely said hello and paid attention to Dr. Gao.

Dr. Gao is a Ph.D. who has just graduated from a master's degree, is a Ph.D., is very strong, is also very arrogant, has rich experience in hardware, is proficient in the use of DSP, DSC, PLC hardware programming, has some attainments in motor control and switching power supply, and is taking the two paste brothers to engage in hardware development.

The two senior brothers were often reprimanded by Dr. Gao, and every time they spoke fiercely, without saving face at all, the two of them were very in awe of him.

"Hello junior brother."

"Hello junior brother."

Liang Shen was completely lost temper by Dr. Gao, and that Huang Jin was also cowardly.

Dr. Gao didn't even look at Lu Jiaren and Liu Ze, nor did he respond at all, still staring at the computer and carefully drawing a two-layer PCB (printed circuit board) with Protel.

Lu Jiaren frowned, a little unhappy, and said in his heart, why are two doctors so weird in this laboratory, a female doctor likes to click the mouse and pretend to be stupid, this third kind of person doesn't care, a male doctor even ignores people at all, damn, am I coming to the wrong place?

The two were about to say goodbye, Dr. Gao put down the work in hand, and said: "As soon as the graduate school comes in, I want to write a thesis, don't be ambitious, first lay a solid foundation, now many masters can't even draw a circuit board, PI and PID feedback can't figure it out, soldering a component, even capacitors, inductors can't be distinguished, conventional switching power supply circuits don't understand, what kind of papers?" ”

This is obviously talking about himself, Lu Jiaren's face changed slightly, and after thinking about it, he was a newcomer for the first time, and if he didn't bother with him, he might indeed be a little anxious.

Liang Shen and Huang looked at each other, afraid of Dr. Gao and did not dare to say anything.

Dr. Gao stood up with a circuit board in his hand, glanced at Lu Jiaren, and asked lightly, "Did you ever do actual hardware circuits when you were an undergraduate?" Nowadays, many people who graduate from undergraduate school do a Simulink, build a model, and do a simulation. ”

"The hardware has also been exposed to some, and I made a PMSM driver board after my undergraduate graduation, but it is very common and very simple, directly copying the ready-made circuit in a book, heh, I have been drawing it for several months, and it took more than a month for the motor to rotate." Lu Jiaren replied in a relaxed tone as much as possible.

"It's okay to be able to debug it," Dr. Gao said with a cold face, "What about you?" ”

"Me?" Liu Ze pointed to himself and said, he didn't expect Dr. Gao to ask him.

"Is there anyone else but you? What projects have you worked on? Isn't it funny to run to the lab at the beginning of the sophomore year? Dr. Gao's brows furrowed in displeasure, and his voice became sharper.

"I've done two projects, one is a music player, and the other is a DC power supply, and I can play with it myself."

"The music player has no technical content, there are few components, a lot of work is done in programming and algorithms, far less complex than the PMSM driver board, is the DC power supply buck or boost structure?" Dr. Gao snorted and asked with a cold face.

Lu Jiaren smiled a little, and said in his heart, hey, my hardware level is very good, my senior brother has praised me, that's not it, our Bingda has always adhered to: strict specifications, kung fu to the home school motto, are real technology, do not play false.

The driver board of PMSM, I drew eighteen versions before finalizing it, and each component was soldered by myself, and it was debugged again, ha, it's really great.

Liu Ze frowned slightly, he was a little displeased with Dr. Gao, people can be arrogant and self-improving, but such arrogance to others is over, and always holding this kind of mentality that Lao Tzu is the best in the world will only limit himself.

"Since you have done a DC power supply, you should know what buck and boost are, Huang Jin, what do you say buck is?" Dr. Gao was even more dissatisfied with Liu Ze's delay in answering.

Huang Jin is really afraid of this senior brother, his temper is too big, but the graduation project and small paper all rely on others, and he doesn't dare to say a word, especially Senior Brother Gao's face is very ugly today, and he doesn't know what gunpowder he has eaten, so he said with a smile: "Brother Kai also told us yesterday that buck is a step-down chopper circuit, which reduces the DC voltage through the duty cycle." ”

"How?" Dr. Gao asked.

"This, you have to have a thyristor, the switch can also do, and then turn on and off."

"That's it?"

It doesn't seem quite right, Huang Jinjin can't remember it for a while.

Dr. Gao raised his voice and said, "I just said yesterday that I can't remember today, is it to add an inductor?" ”

"Yes, yes, there's an inductor."

"How does it work?"

Huang Jin's forehead was about to sweat, so many people looked at it, and the two junior brothers, give me some face.

Dr. Gao said angrily, "What can you learn well? Add an inductor, the switch conducts to form a path to supply power to the load, the switch is disconnected, the parallel diode forms a path, and the freewheeling effect of the inductor continues to be conducted. ”

"Yes, yes, Brother Kai is right." Huang Jin accompanied the smiling face, he must not touch his senior brother's moldy head today, otherwise he will suffer.

"Liang Shen, you talk about boost."

Liang Shen was nervous, "This ...... This is a DC boost chopper circuit with a switch, a diode, and a capacitor. ”

"Is that all right?"

"Poor...... Almost. ”

"How do you boost DC?" Dr. Gao's tone was aggressive, venting the frustration in his heart, he had a good reason to be unhappy today, the girl he had been chasing, just this morning, when he passed by the girls' dormitory, he saw her hugging a boy, and they kissed, the shameless boy hugged her waist tightly, and the two were completely together.

One summer vacation, he is struggling to chase others, the girl is very beautiful, the height is 167, the third year of the media institute, the two of them went out to eat together a few times, watched two movies, the sister even went to the laboratory to study a few times, he occasionally took the opportunity to cross the road or something to grab his arm and did not resist, the girl's skin is delicate and cold, let him be intoxicated, no matter how you look at it, it looks like the rhythm of the future, and even last night's chat is no different from the past, but ...... I saw this thunderbolt on a sunny day.

He thought that the relationship was already very intimate and ambiguous, and the girl was completely regarded as an ordinary friend, and it was only the beginning of the new semester, when he really wanted to rush over and beat the unruly boy, the hand grabbed the handlebar tightly, and the white forehead was bruised, and finally he rode fast to the river and slammed a tree.

"That switch forms a loop every time it opens and breaks, and the duty cycle controls the voltage."

Liang Shen said cautiously.

"You can only lower blood pressure like this, and you can't even lower blood pressure, don't you think something is missing? Don't you want an inductor? Dr. Gao's eyes were terrifying.

"Isn't it an inductor for buck and a capacitor for boost?"

"Do you understand? How is it possible for a capacitor to be boosted? How does the voltage out of thin air come out? Dr. Gao almost roared.

Liang Shen and Huang Jin are also aggrieved, especially the circuit in this book, you can just take a look at it when you use it, who has nothing to remember this thing.

"Inductance, there is also an inductor, the switch conduction power supply is charged to the inductor, the capacitor supplies power to the load, the switch is disconnected, and the power supply and inductor together supply power to the load through the diode unidirectional conduction, so as to achieve the effect of voltage boost."

"Oh, yes, Brother Kai is right, I remember it thoroughly this time."

Dr. Gao glared, Liang Shen and Huang Jin both looked down, he turned to look at Liu Ze, and asked arrogantly, "What kind of structure do you make of DC power supply?" ”

"It's not buck, it's not a boost, because the voltage transformation amplitude is too large, it's the structure of DC-AC-DC."

"How much does the voltage go up?"

“200kV。”

"How often?"

"Less than 100k."

……

After asking a few questions in a row, Liu Ze answered them indifferently, and he was concise and to the point, Dr. Gao, who didn't get out of his breath, frowned, he was very familiar with low-power power supplies, and he had never done this kind of structure, so he couldn't ask any in-depth questions, so he had to give up.

I was still very unhappy in my heart.

Sister Doudou also saw that Dr. Gao was not quite right today, and said with a smile: "What's wrong with Gao Bo today, did you quarrel with that little girl in your family?" ”

It's okay not to ask, as soon as he asked, Gao Bo's face turned red, and the two of them went in and out of the pair many times, whether it was the laboratory or the classmates, they thought it was his girlfriend, and he acquiesced, which undoubtedly embarrassed him, exhaled a few heavily, suppressed his anger, and said: "You are too careful, you think everyone is the same as you, and you will drop things in the laboratory when you quarrel with your boyfriend." ”

Sister Doudou's temper is also very hot, she has a boyfriend who has been talking for many years, but she has been hiding, sometimes she claims to be single and asks for an introduction, she drops her mobile phone directly in the laboratory, and sometimes she suddenly cleans up her things very loudly, which is a quarrel.

After a summer vacation, Gao Bo is naturally clear.

Sure enough, Sister Doudou was very angry, and she didn't dare to reply when she saw Gao Bo's posture of breathing fire, so she stood up and slammed a very thick hard-shell book on the table, followed by several books, and there was a lot of noise.

Lu Jiaren was dumbfounded, this ...... What kind of laboratory is this, isn't it called the group under the fiber optic laboratory? This...... The atmosphere is too different.

"You two come here, what kind of bullshit circuit is designed, common component op amps can be drawn wrong!" Dr. Gao yelled disapprovingly.

The two guys who wanted to graduate stood up helplessly and walked over, Liang Shen took over the counselor of the freshman year, obviously going to stay in school and take the ideological and political route, and there is no point in engaging in technology, Huang Jin is a child of electric power, and he will return to his hometown and the provincial capital power supply bureau after graduation, so naturally he doesn't need to do this.

Gao Bo snorted and said: "We are discussing analog circuits, you two should also listen to it, analog circuits are not like simulation, which can be dragged directly on the computer, and it is not so easy to have good results if it seems to be a simple function." ”