Chapter 538 Be strong and then be small

The reason why the American YF-22 was able to beat the YF-23 and become the first mass-produced fourth-generation aircraft was because it was very stable. Although the YF-22 used so many black technologies that other countries considered, such as LPI radar, stealth coating, stealth aerodynamic shape capable of supercruise, and dual vector engine, it was really very stable and relatively conservative compared to the YF-23.

Oh, by the way, there’s also the 2.0 lift-to-drag ratio, which doesn’t count!

——Comments from a certain country.

Therefore, the mechanical part of the Guangyang Factory did not do any fancy tricks or come up with any original ideas. Instead, it honestly followed Gao Zhendong's requirements and produced the photoelectric encoding disk.

There were no problems with the optoelectronic and mechanical parts, so Gao Zhendong turned his attention to the signal reading and output circuit.

Signal amplification, shaping, pulse output...

Gao Zhendong nodded as he looked at it, which made the comrades at Guangyang Factory feel a lot more at ease. It seemed that President Gao was satisfied with our work.

Gao Zhendong quickly finished reading the signal circuit and looked up.

"Well, it's generally well done. Most of the necessary considerations for the entire circuit have been taken into account. There are a few places that you can take note of and make some modifications."

Mr. Yang immediately turned to a new page in his notebook: "Mr. Gao, please go ahead."

"First of all, don't use electron tubes for this amplifier. Use transistors instead. The current production of transistors is still relatively optimistic. If you are worried about the shortage of raw materials, you can come to me."

I don't know if it was due to design inertia, unfamiliarity with triodes, or fear of insufficient transistor production capacity, but the comrades at the Guangyang Factory used vacuum tubes in the signal amplification part. Gao Zhendong decisively asked to replace it. It's not a power amplifier, so why should he pursue the taste of tubes?

The biggest use of transistors - DJS-59 is now only for export, so the pressure is less. With the increase in 1274 production capacity and the easing of raw material supply, it is not a problem to squeeze some out.

The comrades from Guangyang Factory agreed and secretly admired Gao Zhendong. Mr. Gao is giving us face. We are actually used to it, but we didn't expect that the production of transistors would take such a long time.

As for the benefits of replacing vacuum tubes with transistors, they know it without being told. Not to mention the long-term benefits, the fact that it is sturdy and reliable is enough.

After saying this, Gao Zhendong pointed to several locations on the circuit and said, "Here, here, add a capacitor. It doesn't have to be too big, 104 will do."

The comrades at Guangyang Factory did not quite understand Gao Zhendong's intention: "Mr. Gao, what are the uses of these capacitors? We don't quite understand this. Can you give us some guidance?"

This is a rare opportunity, so just ask. There is nothing to be embarrassed about.

"Anti-interference: If there is a high-power inductive load running nearby, its alternating electromagnetic field will easily generate an induced electromotive force on the line, which will be amplified and turned into a signal output. Using capacitors for filtering can largely swallow these small interference signals."

"Inductive load?"

Without Gao Zhendong's reply, Mr. Yang glanced at his people and said, "Electric motor!"

Oh, I see. It is quite normal to have an electric motor in the use environment of the photoelectric encoder.

"Then can we use a larger capacitor, Mr. Gao?" Bigger is better.

"No, it's too big and will swallow up normal signals. Judging from the characteristics of this circuit, 104 is enough."

Every advantage has its disadvantages, and applied research is often a process of weighing and choosing between trade-offs.

"I understand. Thank you, Mr. Gao." The young comrade from Guangyang Factory wrote it down happily.

Gao Zhendong pointed to the signal output part again, which was also a place that required major changes.

"Here we use two transistors to make a bistable circuit to achieve state flipping and shaping. Now the direct shaping is not very good."

Bistable circuit? This made Mr. Yang confused.

Gao Zhendong took out paper and pen and started drawing a circuit diagram on the paper.

If there is a NAND gate, two NAND gates can make a bistable circuit, but it can be done without it, two transistors will do. In fact, it is the same principle. Gao Zhendong does not have the idea of ​​making a digital circuit just for the sake of a digital circuit. SZ61XXX has not been made yet, so he can't just sit there and wait.

While drawing the picture, Gao Zhendong explained to his comrades at the Guangyang Factory the principles, states, truth tables and other related knowledge of the bistable circuit.

"Using this circuit, firstly, it can further ensure the reliability of the flipping, and secondly, it can also resist interference to a certain extent." After explaining, Gao Zhendong pointed to the circuit diagram and summarized the reasons why this circuit was used here.

Mr. Yang looked at the paper in front of him and felt that he had gained a lot: "Well, I understand. This circuit can indeed ensure the reliability of the flip, but please tell us more about the anti-interference."

Gao Zhendong pointed to a few calculation formulas and said, "In order for the bistable circuit to flip, the incoming signal must meet certain requirements."

After that, he pointed at the two core transistors: "Either the signal polarity must ensure that the saturated tube exits the saturation region, or the polarity must ensure that the cutoff tube exits the cutoff region. At the same time, the pulse signal amplitude that triggers it must be large enough and the pulse width must be wide enough." Mr. Yang thought for a while: "Ah, so that's how it is. The positive and negative of the signal, the energy it carries, and the action time, none of them can be missing, so that the flip can be guaranteed. In this way, it is difficult for the interference signal to meet these requirements at the same time, and the circuit cannot be flipped, which further ensures the accuracy and reliability of the output."

Mr. Yang is also a technician with many years of experience. He may not have seen as many tricks as Gao Zhendong, but he has solid basic skills and figured it out in no time.

"Oh, right, add a peak clip after the output to control the signal level at +5V. You may add a digital control circuit to the subsequent stage of this signal, so there must be a unified level."

"Okay, Mr. Gao." It's not that they couldn't think of this, but they didn't know how much to cut.

After reading this, I learned more about other aspects of the photoelectric encoder and found that there was no big problem.

After the discussion, Gao Zhendong saw them off. The comrades from Guangyang Factory also knew that Gao Zhendong was very busy. Today they were able to solve many hidden dangers of the photoelectric encoder being susceptible to interference and determine the signal output standard. It was already a great gain.

Gao Zhendong returned to the office and looked at the overall plan of the second-generation tank on the computer in front of him. Suddenly, he remembered something, or to be more precise, two things.

He immediately picked up the phone and called the guard at the Third Rolling Mill.

Mr. Yang and his entourage were in high spirits and were walking towards the gate of the Third Rolling Mill. However, they had no car to bring them here, so they had to walk to take a bus and then a train.

As soon as I reached the gate of the Third Rolling Mill, I was stopped by the guard.

"Comrade from Guangyang Factory, please wait a moment." The security guard has an advanced skill - among millions of people, he can recognize at a glance that the person is not from his factory. If the person has entered through his factory, then it is even easier.

"Hello comrade, is there anything we can cooperate with?" Mr. Yang and his colleagues stopped.

"It's like this. Just now, Mr. Gao from the Third Branch called and asked you to go back. He has something to discuss with you."

"Oh, okay, okay, thank you!" After hearing this, Mr. Yang decisively led the team to turn around and return, without any thought of being troubled.

"Mr. Yang, you said that Mr. Gao asked us to go back. What's the matter?" An employee was a little confused.

Mr. Yang thought it through: "It must be a good thing. He probably just remembered it. It's not within the scope of this project. He has a lot of things to do. We are lucky that he remembered it so quickly. Let's move quickly and don't let him wait anxiously."

It took Mr. Yang and his group some time to get back to the reception room of the Third Factory. The procedures they used to enter the first time had become invalid since they left the gate of the Third Factory. It was only after the guard of the Third Factory called Gao Zhendong that they were allowed in.

Gao Zhendong was sitting in the reception room waiting for them. When he saw them come in, he looked embarrassed and said, "I'm sorry, comrades. I just remembered when I got back to the office that there is something that is very suitable for you to do. I had to invite you back. Thank you for your hard work."

Look, how polite Mr. Gao is.

"It's not hard, not hard at all. Just tell me if you have something to say." Mr. Yang said with a smile.

Is there something suitable for us to do? Look, this is something going to happen, haha.

It is indeed a good idea to report work more often.

Gao Zhendong didn't waste any words. After expressing his apology, he immediately stated his request.

“They are still photoelectric encoders, but these two types of photoelectric encoders are special.”

Mr. Yang was delighted. Since it was a photoelectric encoder, the existing technical capabilities of his factory were basically sufficient. As for projects with the word "special" in them, it meant that the purpose was either very special or the requirements were high. These were all good projects that could produce results.

And there are two types! The technical department of Guangyang Factory has solved the workload for the next year.

And with Chief Engineer Gao leading the way, we can definitely cover our situation, and there won't be that embarrassment of wanting to show our face but showing our butt instead.

"Great! Mr. Gao, if you have any requests, please tell me."

"For the first type, based on the existing encoder, there are two requirements, that is, it must be strong! It must work in high temperature and vibration environments, and it must have extremely high reliability under such conditions. At the same time, it cannot be too big. Go back and think about it first. I will contact you later about the specific size requirements."

No wonder the first thing Mr. Gao did when he came up was to replace the electron tube. The electron tube itself is a big light bulb, and it cannot withstand high temperature and vibration, or rather, the things around it cannot withstand it.

"Okay, Mr. Gao." Mr. Yang carefully wrote down Gao Zhendong's request.

"The second one has only one requirement: small! The resolution doesn't need to be high, 3 bits will do, and the zero mark can be removed, but the photoelectric encoder part cannot be larger than 1 cm square. If there is no other way, the maximum can be relaxed to 1.5 cm. The signal recognition output circuit is also required to be as small as possible. By the way, this thing should use at least two channels at a time. You can start from this perspective and consider sharing some things in the signal circuit part."

3-bit accuracy refers to 3 binary bits, which means it only needs to output 8 signals for one rotation. At worst, he can use small gears for acceleration.

(End of this chapter)