Chapter 849: Genius, really good at making decisions!

Regardless of whether he is confused or not, testing circuits is a delicate job. This is the first step in the Russians' long march, and they still have a lot to do.

Several guests came to the 16th Laboratory of the Institute of Electronics, brought by the dean himself.

"Old Li, I have brought you a distinguished guest. Look, I have brought you some good news." The dean of the Institute of Electronics smiled happily as he walked into the office of Director Li of the Sixteenth Laboratory.

"Oh, Comrade Dean, you finally remembered to support us. Thank you so much." Director Li didn't ask what it was about first, but instead used a bunch of nice words to push the dean over the wall. If you don't get some practical benefits today, you will be going back on your word and enriching your comrades!

The dean was very confident about his behavior of taking advantage of the situation. He said, "Don't worry, it's definitely a good thing. It depends on whether you can handle it. If you don't have the ability, you can't blame me for not taking care of you."

Director Li immediately changed his expression: "Don't worry, Dean, I will complete the task!"

The dean, who was somewhat amused by his face-changing skills, introduced: "This is Director Pan and Chief Engineer Cui from Factory 1218. They brought you this mission. If you want to thank someone, thank them."

In fact, Director Li and Chief Engineer Cui know each other. They are both technicians and senior talents in the system. They have dealt with each other many times. However, he is not familiar with Director Pan. The dean cannot introduce only one of them, so he simply introduces them as if they do not know each other.

"Oh, thank you so much, both of you. Come, come, sit down and have some tea." So you didn't even give me tea if I didn't give you any tasks, right?

Several people sat down and the dean did not leave. He still had to let Director Li take the helm of matters such as these that involved multiple units. If there was something that Director Li was not comfortable saying, there would be no problem if he said it out loud.

"Here's the thing. We received several tasks from Chief Engineer Gao. We think one of them is very suitable for your company. It would be a pity if we don't invite you in. So we discussed it with Chief Engineer Gao, and he thought it was a good idea, so we came to bother you."

Director Pan explained the situation first, which was very informative.

The matter was Chief Engineer Gao's, but the recommendation was made by us, and the approval was given by Chief Engineer Gao.

"Chief Engineer Gao? Is that the Chief Engineer Gao?" Director Li's spirits immediately perked up when the name was mentioned. No, he had to confirm it, otherwise his excitement would be in vain.

Chief Engineer Cui smiled and said, "Yes, that Chief Engineer Gao." Who else could it be if he didn't mention the company? It had to be him.

"Oh, thank you so much, leaders. I've done it. Director Pan, Chief Engineer Cui, you've brought me great news." He didn't ask what it was, but thanked them first. These two were higher in rank than him, so it wasn't strange for him to call them leaders.

He had never dealt with Gao Zhendong, but he had met him many times at the Lightning Technology Awards. They just didn't communicate much, but he had a great reputation in the 12th Ministry of Machine Building.

Director Li knew very well that as long as the research project came from Chief Engineer Gao, it would not be a trivial one, but mostly new things. Isn't this much more exciting than copying others' work every day?
He agreed without even asking any questions, so that the two of them would not go looking for someone else.

If you don't decide which unit is most suitable for you, you will feel unsafe.

He knew that there were several units doing the same work as his laboratory. If he had to mention the advantages, perhaps the only one was that he was in Beijing. This was his biggest advantage. However, the Guangyang Factory, which was directed by Chief Engineer Gao, was also not in Beijing. But this did not prevent the Guangyang Factory from winning many awards under his guidance. They even made a lot of use of a rotary encoder.

I heard that now they can be self-reliant and develop more product categories based on the theoretical and practical experience gained.

This is called the master leading you to the door. The practice is up to the individual, but leading you to the door is very important.

"Haha, it's all for work. Lao Cui, please introduce the specific matters to Director Li." Director Pan said with a smile.

Director Li opened his notebook, sat upright, and said, let's get down to business, be serious.

"Chief Engineer Gao wants to develop a new power electronic device, which is an improvement on the thyristor." Thyristors and thyristors are the same thing, just look at which name you are more comfortable with.

"SCR? Great, this is our specialty. What are the main improvements?" Director Li was satisfied when he heard it! It is something he is good at, or at least familiar with, and it has new features and improvements. This kind of work is so exciting.

"According to Mr. Gao, there are not many improvements, just two. One is that it can shut down itself, and the other is that the operating frequency is higher than that of ordinary thyristors." Chief Engineer Cui said.

Isn't that enough? Director Li's eyes almost popped out.

There are two biggest problems with the current application of thyristors.

First, the thyristor is a semi-controlled device. It can only be turned on but cannot be directly turned off by a control signal. If the thyristor wants to be turned off, it can only be done through a complex and large external circuit to perform current or phase switching. This method is slow, the system is complex, large and heavy, costly, inefficient, energy-intensive, and has limited applications.

The second is the low operating frequency, which sometimes makes it difficult to perform transmission and transformation tasks.

"Isn't that enough? Mr. Cui, the two problems that Chief Engineer Gao improved are basically the biggest problems of SCR at this stage. The remaining problems are relatively easy to solve. It's amazing that we can solve these two problems."

Director Li sighed inwardly, thinking that Chief Engineer Gao was both generous and too modest.

I didn't solve many problems, just two. But this modesty made him feel uncomfortable, because it was too modest.

Maybe in other people's eyes, it really isn't much.

Even the director of the Institute of Electronics was stunned when he heard this answer. At first he only knew that there was work to be done from Chief Engineer Gao, and that it was closely related to Office 1218, so he hurried over with his comrades from Factory .

Who would have thought this would be such a big deal!

For those who work on power electronic devices, being able to solve these two problems of SCR is like opening up a new path.

"Director Pan, Chief Engineer Cui, is this true?" He couldn't believe it, even though Gao Zhendong's reputation was here.

"Anyway, that's what Chief Engineer Gao said. I don't think it's a big problem." Chief Engineer Cui thought happily about the optocoupler and MOSFET in his hands, thinking that this thing was absolutely reliable.

"Don't worry, even if I have to mobilize all the manpower of Room 16, I will definitely complete Chief Engineer Gao's project." Director Li patted his chest and said, "Copy, copy for a living!" Even if he had to stop the copying work, he had to do a good job on this end.

"Well, the hospital supports you!" The dean was also very clear. It would be a pity to miss such a good opportunity.

Seeing their attitude, the two people from Factory 1218 smiled, as expected: "Well, since you have no objection, let's go and see Chief Engineer Gao."

"No problem! Absolutely no problem. Let's go now?" It's too fast. I'm not ready yet.

"Let's go now. We have an appointment with Chief Engineer Gao in the next two days. We can meet anytime in these two days. After today, it will be hard to say."

When the Dean and Director Li heard this, they realized that this was true. As for Chief Engineer Gao's work arrangement, the fact that 1218 could be arranged like this showed that Chief Engineer Gao attached great importance to this matter and it could not be delayed.

"Let's go, Dean. I'll go first." Director Li didn't hesitate. He picked up his bag, grabbed a copy of the overview of his laboratory, and ran after the comrades from 1218.

An hour later, he was sitting in the reception room of the Third Factory with his comrades from 1218.

"The third rolling mill and the third branch factory, Tsk~~~~" Looking at this place, he and other comrades from the system sighed as if they were here for the first time. Talking about such things in this place, and it was the other party who was in the lead, always felt a little unreal. It seemed that this profession was not right.

When they saw the young Gao Zhendong, the feeling of unreality became even stronger. Although they had met him many times, many comrades were still not used to his youth.

"Come on, come on, now that we are here, let's get started. Let's make GTO, gate turn-off thyristor."

The full name of this thing is really long, so Gao Zhendong simply used its English name and abbreviation.

Gao Zhendong drew a structural diagram of GTO directly on the blackboard.

This is his choice. Under the current environment, it is the most easily realized fully controlled high-power power electronic device, which has a wide range of applications, a long life cycle and a relatively appropriate cost.

This product can still stand the impact of IGBT and has a wide range of applications, which shows its capabilities.

In terms of the limit, at the same frequency, its power is slightly lower than that of SCR, but the difference is not very large. We probably don’t need such a high power now, but it can work at a frequency that SCR cannot reach. For us at the current stage, this is even more important than the maximum power.

Looking at the structural diagram gradually taking shape on the blackboard, Director Li felt very familiar at first, because this part was simple and Gao Zhendong had drawn this part first.

In terms of principle and structure, he could tell at a glance that the beginning part was exactly the same as the two layers of the typical four-layer three-terminal PNPN structure of SCR.

Oh, this thing is called a gate turn-off thyristor? That's fine, the structure is almost normal.

But when Gao Zhendong painted the third and fourth layers, things changed.

The third gate and fourth cathode of SCR are clearly divided into two layers, but the cathode of GTO is divided into many layers, each of which is surrounded by the gate, which is a multi-cathode structure.

"Let's use the dual-transistor model to analyze it..." Gao Zhendong patted the chalk dust off his hands and started teaching them directly. This is the most core part, so they must listen carefully.

"…From the above, we can see that when a sufficient positive pulse signal is applied to the gate, it is enough to make the cathodes of the GTO enter a large-area conduction state. However, due to the structure, the conduction of the GTO is a critical conduction, which provides the conditions for the gate negative pulse signal to turn off. Correspondingly, the device saturation of the SCR is deeper and there is no turn-off condition. This is the biggest difference between the two."

Genius! This was the only thought in Director Li's mind.

(End of this chapter)