Xin Zhai

Two weeks later, the finished board arrived.Ye Li and his two senior brothers started to do the test.The results of the first two days of testing were close to the simulation results.On the third day, the waveform in the oscilloscope changed suddenly.What was supposed to be a square wave, or a rising edge, turned out to be an exponentially rising curve.

Tong Yan came over and spent a day looking it up, but he could only understand that the chip or a certain component was broken, which was an accidental event.So the board can only be re-made.This time he found a few more manufacturers of circuit boards and divided the time slots.In this way, even if there is a problem with the board, there is always a spare, so you don't have to wait.

As soon as the new board arrived, several people worked non-stop.As a result, only a few correct waveforms were seen this time, and the next day's results went wrong again.

By this time a month had passed.The department holds a project progress meeting every two weeks, at which teachers report on the progress of their projects.Tong Yan, a project that everyone is staring at, has not made any progress since the end of last semester. This time, he was named and criticized by the leader.

Tong Yan had to suspect that there was a problem with the parameters of the circuit, so he began to modify the parameters.It is still the previous steps, design and simulation, and then make the board.Because the parameters cannot be completely determined, they are all crossing the river by feeling the stones, so the modification process is very cumbersome.

Ye Li spends all his time and energy on projects these days, except for classes and tutoring, he spends all his time with Tong Yan.After working for so long, everyone is very anxious.Yang Ziyue was sick for several days.Zhou Tongyan's voice is also hoarse this week.

Tong Yan came here with a hoarse voice for two days, and on the third day, he sent a message to Ye Li, saying that he went to the hospital, the doctor told him to rest, and told Ye Li to work quickly in the department hall.

Ye Li replied, "Shall I go see you?"

"Don't come, you're helping me by finding out what's wrong with the board. It's the flu, so I won't infect you."

Ye Li thought that his dormitory was very close to the cafeteria, so a cold should not be a big deal, so he concentrated on working in the laboratory.

The day after Tong Yan didn't come, Yang Ziyue came and Zhang Zhen fell ill again.Yang Zi was more unfamiliar with the progress, so he helped Ye Li by the side.Ye Li tested again according to the two circuit parameters updated by Tong Yan, and the results were the same.

He was very discouraged. Something must have gone wrong, but what was the problem?Is there a problem with the quality of the chip?So why is it good to start?

"Where's Teacher Tong, isn't he here?"

The two were busy, Ye Li turned his head and saw that Dean Li walked into the room slowly.

"Hello, Dean. Teacher Tong is sick."

"Ill? What kind of illness?"

"I can't speak from my throat, I have a bad cold."

"How can we rely on the students if the teacher doesn't come? Hurry up."

Ye Li smiled and said: "Teacher Tong was still there the day before yesterday, don't worry, we will not stop without Teacher Tong."

Ye Li actually wanted to see Tong Yan, but today's test results negated all the parameters that Tong Yan had modified before.He didn't want to tell him the news.Even if there is a little bit of good results, he can proudly tell Tong Yan that the project has progressed.

Ye Li checked the components one by one, and there was no problem, that is to say, it can basically be concluded that the chip is broken.Now that they had no spare chips in hand, he called the chip manufacturer and asked them to send more samples, and asked the manufacturer how to judge whether the chip was good or bad.The manufacturer gave him a table, dozens of pins, each pin is loaded with a certain voltage, and the corresponding waveform should be obtained.

The pins of the chip are very small, and the two of them nestled on the table all afternoon and tested all the chips in the circuit.All the chips were spared and all were broken.

Yang Ziyue said, "Tell Teacher Tong about it."

"Okay." Seeing that it was already nine o'clock, Ye Li sent a text message first because he was afraid of disturbing Tong Yan's rest.

"The test is over today, and the result is still the same. It has been determined that the chip is broken."

Tong Yan replied quickly: "Contact the manufacturer and ask them to check."

"Okay. How are you?"

"Better."

Ye Li knew that Tong Yan was suffering from a sudden illness.The laboratory is full of computers and instruments, the air is very dry, and the environment is not good.The most urgent task now is to find out the cause. If there is a problem with the design of the chip and it cannot be improved in a short time, it will face the problem of changing the chip and reprogramming.

Ye Li thought about it, and called the manufacturer's technical consultant again.

"Zhang Gong, what might be the reason why the chip is broken? Is there a quality problem?"

"This does not rule out this possibility. After all, we are also a newly developed product. When we tested you last year, did such a thing happen?"

"No, but last year's test circuit was simpler."

"Well, it's possible that the voltage load is too high. You send back the damaged samples, and we'll check, but it will take time."

"We are in a hurry now." Ye Li asked again, "What are the common reasons?"

"Well, the possibility of electrostatic breakdown is not impossible, but it should not be great."

"Static breakdown?"

"Yes, the voltage of static electricity is very high. This has to be measured with an instrument, and it can be measured."

The next day, Ye Li spent the whole morning looking up things related to static electricity and electromagnetic compatibility.This is a completely new field. So far, only some mobile phone manufacturers and a few universities have done relevant research.But the conclusion is very certain, static electricity can cause damage to chips and electronic components.Usually when doing circuit tests, they will do a certain degree of electrostatic protection, but some sensitive components will still be affected.

The more Ye Li looked at it, the more he lost his mind. This seems to be completely beyond the scope of Tong Yan's research.

At this time, the phone rang suddenly, and Ye Li saw that it was Liu Na calling.

"Ye Li, is Teacher Tong sick?"

"Yes, I have a cold."

"Shall we go and see him?"

"He told me not to let me go." Ye Li thought for a while, "Let's go, let's go together."

Ye Li called Yang Ziyue to go to Xinzhai.It was a cloudy day early in the morning, and the wind was very cool.At this moment, thicker and darker clouds came from the east.

When they arrived at Xinzhai, Liu Na, Zhou Shi, and Lin Congshan were already waiting at the door.

"Come on in, it's going to rain."

Several people walked in, passed through the dark corridor, and arrived at the door of Tong Yan's house.

"Teacher Tong."

Several people knocked on the door and entered the house.

Although it was daytime and the room was very dark, Ye Li watched for a long time before he could tell where Tong Yan was.Tong Yan was lying on the bed, unable to see his face clearly.

"Why are you here? Don't tell me a word." Tong Yan's voice was still hoarse.Ye Li found the light switch on the wall and turned it on.

The moment the light came on, Ye Li looked at Tong Yan and saw that he was also looking at himself.His heart skipped a beat, and he immediately regretted it.He should have come earlier, he should have come as soon as Tong Yan didn't go to the office on the first day.

The corners of Tong Yan's eyes were red, his face was also flushed, his hair was messed up, and a large blister formed at the corner of his right mouth.

When everyone saw it, they quickly surrounded it.Ye Li stood behind, scolding himself ten thousand times in his heart.

Tong Yan was so sick that he couldn't go to work, it must be very serious.He didn't let him come, why did he listen.

"Ye Li," Tong Yan pointed to the drawer of the desk, "There is a mask inside, get me one, don't infect you."

"I saw that you said you didn't go to the department hall, so I guess you must be seriously ill." Liu Na took the mask from Ye Li and put it on for Tong Yan.

Tong Yan put on a mask, his eyes were bent, and he said slowly: "I haven't been sick for several years, and a cold is so bad. Just take a look and go, this room is full of viruses."

Several people chatted for a while, asked about his condition, and reported on the recent situation in the class.

Zhou Shi poured water for Tong Yan, and asked if he would like to buy him some food.

Tong Yan said lazily, "No, I can't eat anything."

Everyone sees that he is not in good spirits.Liu Na said, "Let's go, don't disturb his rest."

Ye Li has been squeezed behind by them all the time, unable to speak.Yang Ziyue turned off the light, and the room became dark again.

Several people quietly turned and walked towards the door.Ye Li stayed where he was, and was about to say "I'll stay a little longer", when Tong Yan said, "Ye Li, don't go yet."

So he changed his mouth and said "OK".

It was getting darker now, as dark as five o'clock in winter.The branches of crabapple trees outside the window began to sway.

Ye Li took a few steps and walked to the bed.

The bed was one of those old-fashioned ones with a very low bottom bunk.Ye Li then squatted and knelt beside him.The room was extremely dark, he leaned over and saw Tong Yan's eyelashes blinked, and there was only blackness in his eyes.

Ye Li didn't ask Tong Yan why he called him, and Tong Yan didn't say either.

"Take off the mask, it's uncomfortable to wear." Ye Li said softly.

"Ah."

Ye Li gently took off the mask for him, revealing Tong Yan's thin face.

"I'm so stupid, you believe everything you say."

"This is the first time for me to have such a bad cold. The doctor asked me to go to the hospital for an infusion, but I didn't even have the energy to do it."

Ye Li's heart ached as if being grabbed by someone.He finally understood that when someone said "willing to be sick for him", it was not selfishness, but a self-interested choice made by his heart unable to withstand the pain.

"Are you sleepy? Go to sleep for a while." Ye Li had a lot to say, but was afraid that he would lose energy.He didn't ask Tong Yan why he asked him to stay, and Tong Yan didn't mention it either.

Tong Yan shook his head: "I've been lying down for two days. I'm groggy and can't sleep. It's uncomfortable to lie down. The countdown is like years. It's better to be in the laboratory."

Ye Li thought, the laboratory where you are not there is just a place for instruments.He didn't speak, got up and went out, wet the towel, and wiped Tong Yan's face when he came back.

When wiping his face, he touched Tong Yan's forehead, it was cold.So he was relieved and began to report to Tong Yan about the past two days in a low voice.

"I wanted to tell you that the board had a good test result, but I didn't expect it to be the same again. I called the people from the manufacturer yesterday and they said it might be an electrostatic breakdown."

"I have been checking the information this morning. Indeed, some notebook and mobile phone manufacturers are currently considering adding electrostatic protection components to the circuit. But the chip we use still needs to be tested to be sure."

After listening, Tong Yan said, "Ms. Zhou from the Institute of Electrostatics, Department of Physics, you can look for him."

"Okay, I'll go tomorrow." After Ye Li finished speaking, he changed his words and said, "I'll stay here with you when you get better."

"No, you think I'm dying." Tong Yan smiled, "The project is progressing, and you are helping me the most."

"But you don't even have a pourer."

Tong Yan was silent for a while, then answered irrelevantly, "I'm not a child."

At this time, the wind was strong, and the window was blown open with a bang.The wind gushes in, mixing the smells of sea water, mud, grass, crabapple leaves, and the rubber track of Xi'an.Ye Li got up and closed the window, and went back to Tong Yan's bed.

His heart was swollen by the sea breeze, and the words he had been wanting to say beat in his heart.He felt that he had to say it at this moment, otherwise he might never have the chance.

"Teacher Tong," Ye Li had no place to put his hand, so he tightly grabbed Tong Yan's bed sheet, "If you like boys, you can like me!"