Chapter 773: We have solar cells, but what about batteries?

The happiest people, of course, are the comrades working on PD radars. As for the comrades working on other radars, even those working on early warning aircraft radars, they are not worried about replacing the digital signal processing board with a digital signal processing chip, at least if the demand is not extremely urgent. For them, this news is like the sound of nature.

The original 8 to 16 circuit boards can now be solved with one circuit board of similar size. After calculating the weight, it will be at least 200 kilograms if not 150 kilograms.

As happy as they were were the comrades at the Military Communications Institute who were working on individual soldier communication radios. Originally, for them, digital signal processing boards were meaningless. Once the size reached a certain size, they lost their meaning. They couldn't be installed anyway, so it didn't matter if they were bigger or smaller.

So even though I was envious of the many capabilities brought by the digital signal circuit, I still rationally gave up using this thing on a device at the level of a single-soldier radio.

Even so, the necessary encryption circuit combined with digital logic circuits still makes today's individual radios look a bit bloated.

But now all of a sudden, there is only a little bit left of that large circuit board.

Oh, Heaven and Earth, good things happen every year, and today they come to my home.

They even have an urge now.

"Boss, how about we delegate the overall function to a lower level?"

"Decentralize the overall functions to a lower level?" This proposal even moved the usually rigorous boss.

"With this, now the main thing is the power circuit and power supply." If the other circuits had a foundation laid before, then the small-volume power circuit and power supply immediately gave him trouble.

"The power circuit should not be a big problem. Factory 1274 is not only making ultra-fine large-scale integrated circuits, but also developing power devices that can handle higher currents and higher powers."

"Oh? Really?" The boss turned and looked at him.

If the power circuit problem can be solved, then the remaining power supplies will be slightly easier to deal with. At most, we can bring a few more. Just treat this thing as ammunition. Originally, this was also a weapon for the communications soldiers.

"Really, I have classmates working in Factory 1274. They are very powerful now." The researcher even revealed a mischievous look like a child.

"Well, let's do this. Ask the committee to ask the 12th Ministry of Machinery if they have any new ideas for batteries. If they do, that's even better. If not, this is fine. A smaller circuit means less power consumption. Maybe the power saved by the digital signal can even help to subsidize other functional parts."

They don't have Gao Zhendong's face, and they can directly mobilize resources between these ministries without the need for coordination with their superiors.

For them, electricity is never enough.

"okay!"

When the chief engineer of the Defense Work Committee heard the request of the comrades from the Military Communications Institute, he took the letter requesting assistance and read it for a while. Then he seemed to remember something, stood up and walked directly to the leader's office.

"Leader, take a look at this."

He handed the military communication office's request report to his leader.

The leader looked at it and seemed to remember something: "Oh, I remember, the comrades working on satellites also raised this question not long ago. Last time, we discussed everything except this."

"Yes, Gao Zhendong didn't even mention this. It seems that it is still technically difficult."

For today's satellites, it doesn't really matter what kind of battery the first satellite is equipped with. For the time being, that satellite will just be launched into space to let the whole world hear it.

It’s just that this sound is very important.

Therefore, Gao Zhendong strongly agrees with the idea of ​​taking a short, quick and easy approach for the first launch without delving into technical feasibility and practicality.

Some enemies are very courageous, but as long as they prove that they have basic capabilities, they will be more restrained at certain times.

But the second one is different. It is a technical test satellite prepared for the third photographic meteorological satellite. The technology on it must be well inherited with the third satellite.

"What do the satellite comrades say?"

"The battery they selected for the first one was a silver-zinc battery."

"Silver-zinc battery, this thing doesn't sound cheap." The leader of the Defense Work Committee was still very simple. Half of the materials require silver? That must not be cheap.

"Yes, it is not cheap. This is one of the characteristics of this battery. But the most troublesome thing is not here."

"Oh? Not here? I think the high cost is the biggest problem. But we can still afford to use some of the radio and satellite. We have quite a lot of money on hand." The leader of the Defense Work Committee said with a smile.

The chief engineer shook his head. "The biggest advantage of this thing is its high energy density. It is the battery material with the highest energy density that we know of now, and it can also be used in disposable or rechargeable batteries."

“That’s great! It has a high energy density and can be recharged. This thing is naturally designed for satellites.” The leader was a little puzzled.

"The problem lies in the charging process. Although the silver-zinc battery can be charged and has decent charging and discharging characteristics, its other parameters are not very good. It has a short lifespan and is prone to internal short circuit failures. In addition, it is very expensive..."

For the leaders, now they understood everything. This thing is fine to use on the first disposable satellite, and it can also be used on basically disposable electric torpedoes, but it is not reliable at all for satellites and individual communication equipment that need to be repeatedly charged.

In Gao Zhendong’s previous life, he saw that the lifespans of our earliest satellite platforms were short, but there was actually no mysterious reason for this.

——The projected weight is insufficient, and other equipment is backward. Even if the same weight is projected, the fuel, batteries, and solar cells will be much less, so the life span will be shorter.

You may be able to give dozens or hundreds of specific reasons, but at the root of it are just these few.

"What about using lead acid? At least it can store some electricity." The leader laughed.

The chief engineer was so angry that he laughed. This thing won’t work.

"Leader, that won't work. The energy density of lead-acid is too low."

"The energy density of lead-acid is about 30~50Wh/kg, while the theoretical energy density of silver-zinc is 120~300Wh/kg."

The leader smiled and asked a question: "What is our lead-acid and silver-zinc?"

The chief engineer blushed: "Not far from the lower limit."

Well, you asked about the key points, which made people feel embarrassed.

"It's not far from the lower limit... It seems that it really can't be used." The leader nodded. Although he didn't know the specific technical details, if a relatively poor one could only take the lower limit, then it would undoubtedly lose its meaning.

"Do you want to bring this matter up for discussion?" "Yes, I want to ask Gao Zhendong what he thinks first."

"What does he think? He didn't bring it up during the last meeting. Judging from his style, it's likely that he doesn't really understand the matter."

"That's because the comrades working on batteries didn't mention it. Gao Zhendong didn't know that he was facing such a situation. If he knew, maybe there would be a turnaround?"

"Well, you do have a point. If I remember correctly, when he talked about solar cells, he said something like 'let's put aside the battery part for now'. There are many possibilities for this sentence."

The leader laughed.

The chief engineer was shocked by the leader's attentiveness, and you are just thinking about this?
After the agreement, he called the Third Rolling Mill's Third Branch, and Gao Zhendong answered the call.

"Batteries? Oh, rechargeable batteries, right? Sure, sure. Please ask them to come over. I'll take a look at the situation first."

Gao Zhendong agreed readily and patted his chest.

"Well!"

For Gao Zhendong, the last result of the little black book is still in his hands.

He now remembered that the last time he attended the functional satellite planning meeting, he always felt that he had forgotten something when he came back, but he just couldn't remember it. It turned out to be this matter.

Don’t underestimate this matter, as it determines the life of the satellite, because solar panels cannot be designed with maximum redundancy, otherwise they will not be able to bear the projected weight.

At this time, smaller size and weight come in handy.

People came very quickly. They were not from satellite industry or military communications, but from the Ministry of Chemistry.

Well, the first two departments are just for use, but this ministry is the one that really deals with batteries.

The comrades from the Department of Applied Chemistry walked into this place with some curiosity. They had never heard of this unit or this person before.

But it looks like it belongs to the 17th Ministry of Machine Building, so I guess it's also in the materials business?
It's just that the difference between the two materials is a bit big.

They sat down in front of Gao Zhendong, and Gao Zhendong asked him directly without any hesitation.

"Comrade, let's not talk about the individual radios for now. What kind of batteries are you considering for the satellites?"

"Silver-zinc, but with our silver-zinc battery technology, if we use silver-zinc for the second one, the lifespan and reliability will be very poor. So we are still looking for a suitable material."

This is what the chief engineer of the Defense Work Committee said before they came.

"Just answer whatever is asked truthfully. There is no need to hide anything, no need for permission again, and no need to report again. This will save a little time."

This slightly outrageous request made them all curious about who this great god was.

But when they saw Gao Zhendong, some people realized that they knew him! Isn't this Comrade Gao Zhendong who works in computers? Why did he come to him for batteries?
However, the Defense Work Committee would not let them down, so they felt relieved.

"Silver-zinc does have some problems, and it's right not to force a choice." Gao Zhendong had no intention of forcing the promotion of silver-zinc to show off. This thing is inherently flawed, and forcing it would be digging our own grave.

Just like lithium sulfur and lithium air, are they strong?
But can it be used? In this day and age, Gao Zhendong feels that even mentioning it is a sin.

Forget about those things today. It took decades to solve the problem of lithium dendrites, and the battery may short-circuit after just a few charges.

Seeing that Gao Zhendong agreed with their inference, the comrades from the Department of Applied Chemistry were very happy. No matter what, the first step was that the experts recommended by the Defense Work Committee recognized their judgment. This sense of recognition was very refreshing for the technical personnel.

"So what do you prefer now?" Gao Zhendong asked with a smile.

"Nickel-cadmium battery!" As expected, nickel-cadmium batteries are already available these days and have begun to be promoted and used in China.

The comrade from the Department of Applied Chemistry was obviously an expert at giving reports. He stated the reasons before Gao Zhendong asked for them.

In addition to the fact that all other requirements are basically met, the most important thing is that the energy density of cadmium nickel batteries can be 0.5 to 1 times higher than that of lead-acid batteries!
Of course, how much higher depends on the specific plan, but in short, it is undoubtedly superior to lead-acid.

Gao Zhendong smiled and said, "Well, this is a good idea, but there is only one problem that is a bit troublesome. How do you solve the memory effect?"

The memory effect of cadmium-nickel batteries is extremely notorious. Even some strange habits of other batteries when used later were left by the cadmium-nickel batteries at that time.

This is the key issue.

"According to the working status of the satellite, it is best to use floating charging to ensure that there is power at any time if possible. However, this will conflict with another characteristic of nickel-cadmium batteries, the memory effect."

Simply put, floating charge means charging with a little bit of electricity. This method is used on cadmium nickel, and it can basically destroy cadmium nickel quickly.

If you charge after discharging, you need to consider whether the satellite can shine on the sun. If not, what should you do in advance? In short, the charging management algorithm is very troublesome.

"Ah... this... we are considering using a more complex charging management algorithm. Now that we have a single... single-chip microcomputer, we can afford to arrange a separate computer to run our charging management program and other comrades' solar panel direction control functions."

Oh, I almost forgot that the single-chip microcomputer was also invented by the young chief engineer in front of me. The Defense Work Committee and the 12th Ministry of Machine Building did not hide this matter.

"Well... this is a good idea, but overly complex control is not good. For automatic control, to complete a specific function, I prefer the control system to be as simple as possible."

Although I don’t know where Gao Zhendong gets the confidence to say this, he is not wrong.

"So Chief Engineer Gao, what is your suggestion?"

"Let's make a new battery. I've already made a prototype battery. The charge and discharge characteristics are not bad. The energy density is 30% to 50% higher than that of nickel-cadmium. The charge and discharge times have been tested to 500 times, and it's still normal. We're still continuing the test."

"Chief Engineer Gao, this is impossible!!! Is the energy density of this thing almost catching up with that of silver-zinc batteries?"

"It's still a little worse, but it's more reliable than silver-zinc. Of course, compared to cadmium-nickel, it has one biggest advantage, which is that the memory effect is much milder!"

"What kind of battery is this?" The comrade from the Department of Applied Chemistry was completely interested! But he had no idea what kind of battery this thing was, because this battery had not been invented until then.

"Nickel-metal hydride battery!" Gao Zhendong said with a smile.

(End of this chapter)