Chapter 773: We have the solar battery, but where is the battery?
The most exciting thing is, of course, comrades who are engaged in PD radars. If we talk about comrades who are engaged in other radars, even comrades engaged in early warning aircraft radars, it is okay to replace the digital signal processing board with a digital signal processing chip, at least if the demand is not very, very urgent. , then for them, this news is equivalent to the sound of nature.
The original 8 to 16 circuit boards can be solved with one circuit board of about the same size. Calculating the inside and outside, there is not only 150 kilograms but also 200 kilograms.
Just as happy as them were the comrades working on the individual communication radio station at the Military Communications Institute. Originally, to them, the digital signal processing board was meaningless. Once the size reaches a certain level, it loses its meaning and cannot be installed anyway. It doesn't matter if it's bigger or smaller.
Therefore, although I am eager for the many capabilities brought by digital signal circuits, I still rationally gave up using this thing on equipment of the level of individual radio stations.
Even so, the necessary combination of digital logic circuits and encryption circuits still make today's individual radio stations a bit bloated.
But now suddenly, only a little bit of such a large circuit board is left.
Heaven, earth, good things happen every year, and they came to my house today.
They even have an urge now.
"Boss, what do you think of us delegating the overall functions to one level?"
"Decentralize the overall functions to one level?" This suggestion made the always rigorous boss tempted.
"With this, the main thing now is the power circuit and power supply." If other circuits have a foundation laid in front, the small power circuit and power supply immediately gave him a problem.
"The power circuit should not be a big problem. Factory 1274 is not only making ultra-fine large-scale integrated circuits, but also power devices that can bear larger currents and higher powers are also developing simultaneously."
"Oh? Really?" The boss turned to look at him.
If the power circuit problem can be solved, then the remaining power supplies will be slightly easier to deal with. At worst, how many more power supplies should I bring? Just treat this thing as ammunition. Originally, this was also a weapon for the signal corps.
"Really, I have classmates in Factory 1274, and they are so powerful now." The researcher even showed a naughty look like a child.
"Well, in this case, you entrust the committee to ask the 12th Machinery Department if they have anything new about batteries? If they have it, it would be better. If not, this one will do. Anyway, the circuit is smaller. It brings smaller power consumption, and maybe the power saved by the digital signal can also subsidize other functional parts.”
They don't have the face of Gao Zhendong. They can directly mobilize resources among these ministries without coordination from superiors.
For them, electricity is never enough.
"Okay!"
When the chief engineer of the National Defense Working Committee heard the request from the comrades of the Military Communication Office and read the letter requesting assistance for a while, he seemed to remember something, stood up and walked directly to the leadership office.
"Leader, look at this."
He handed the general office's request report to the leader.
The leader looked at it and seemed to remember something: "Hey, I remembered it. The comrades working on satellites also raised this issue not long ago. Everyone discussed everything last time, but this was the only one that was not discussed. ”
"Yes, Gao Zhendong didn't even mention this matter. 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 is just installed so that the whole world can hear about it.
It's just that this sound is very important.
Therefore, the first one went short and fast, without delving into the technical feasibility and practicality. From Gao Zhendong's perspective, he also fully agreed.
Some enemies may be bold or petty, but as long as they have proven their basic abilities, they will be more restrained at some point.
But the second one is different. It is a technical test star prepared for the third photographic meteorological satellite. The technology on this must be well inherited from the third satellite.
"What do the comrades who work on satellites say?"
"The battery they selected for the first one was a silver-zinc battery."
"Silver-zinc batteries, these things don't sound cheap." The leader of the National Defense Work Committee is still very simple. Half of the materials use silver? That's definitely not cheap.
"Yes, it is not very cheap. This is also one of the characteristics of this battery, but the most troublesome thing is not here."
"Oh? Not here? I think the cost is already the biggest trouble. But if you use a few radios and satellites, they are still affordable. We have a lot of them on hand." The leader of the National Defense Work Committee laughed.
The chief engineer shook his head: "The biggest advantage of this thing is that it has high energy density. It is the battery material with the highest energy density that we know now, and it can also be used in disposable or rechargeable batteries."
"Isn't that great! It has high energy density and can be recharged. This thing is designed for satellites." The leader was a little confused.
"The problem lies in the charging. Although the silver-zinc battery can be charged and has good charge and discharge characteristics, its other parameters are not very good. It has a short lifespan and is prone to internal short-circuit faults. In addition, the cost is very high..."< br>
For the leader, it is now fully understood. This thing is fine for use on the first disposable satellite, and it can also be used on basically disposable electric torpedoes, but for satellites and individual soldiers that need to be recharged repeatedly. Communication equipment is not reliable at all.
In Gao Zhendong's previous life, he saw that our earliest satellite platforms had short lifespans. In fact, there was no very mysterious reason.
——The projection weight is insufficient, and other equipment is lagging behind. Even if the weight is the same, the fuel, battery, and solar cells will be less, and the lifespan will be shortened.
There may be dozens or hundreds of specific reasons, but these are the fundamental reasons.
"What about using lead-acid? At least it can save some electricity." The leader laughed.
The chief engineer was very happy, this thing is not good.
"Leader, that's not possible. 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: "How much are our lead-acid and silver-zinc supplies?"
The chief engineer blushed: "It's not far from the lower limit."
Yes, asking about joints makes people feel embarrassed.
"It's not far from the lower limit...then it seems that it really can't be used." The leader nodded. Although he didn't know the specific technical details, he could only lower the limit for an already relatively poor one, which would undoubtedly lose its meaning.
"Do you want to bring this matter out to tackle the problem?" "Well, I want to ask Gao Zhendong's thoughts first."
"What's his idea? He didn't take the initiative to bring it up in the last meeting. Judging from his style, there is a high probability that he doesn't quite understand this matter."
"That's because the comrades who worked on the battery didn't mention it. Gao Zhendong didn't know that he was facing such a situation now. If he knew, maybe there would be a turn for the better?"
"Well, what you said makes sense. If I remember correctly, I remember that when he talked about solar cells, his original words were roughly 'leave aside the battery part first.' There are many possibilities for this sentence."
The leader smiled.
The chief engineer was shocked by the leader's attentiveness. Are you just thinking about this?
After the agreement, he called the third rolling mill and Gao Zhendong answered the call.
"Battery? Oh, rechargeable battery, right? Okay, okay, no problem. Please invite them over. I'll understand the situation first."
Gao Zhendong agreed and patted his chest.
"That's good!"
For Gao Zhendong, the little black book from last time still has the last result in hand.
Now he remembered that when he went to attend the functional satellite planning meeting last time, he always felt that he had forgotten something when he came back, but he just didn't remember it. It turned out to be this.
Read the original text in Liu#9@书/吧!
Don't underestimate this matter. This matter determines the lifespan of the satellite, because it is impossible to design solar panels according to maximum redundancy, and the projected weight cannot be carried.
At this time, the smaller size and weight can come in handy.
The people came very quickly. They were not from satellites or military communications, but from the Ministry of Chemical Industry.
Well, the first two departments are just for use, and this ministry is really engaged in batteries.
Comrades from the Chemical Department walked into this place with some curiosity. They had never heard of this unit or this person before.
But it seems to be affiliated with the 17th Machinery Department, so it can be considered as a material supplier?
It's just that the difference between the two materials is a bit big.
They sat down in front of Gao Zhendong. Gao Zhendong didn't delay and asked him very directly.
"Comrade, let's not talk about the individual radio stations. What batteries are you considering for the satellites now?"
"Silver-zinc, but with our silver-zinc battery technology, if the second battery uses silver-zinc, the lifespan and reliability will be very poor. So we are still looking for suitable materials."
Before they came, the chief engineer of the National Defense Work Committee said this.
"You answer truthfully whatever is asked. There is no need to hide, no need to give permission again, no need to report again. This can save some time."
This slightly outrageous request made them all curious as to which great god this was.
But when they saw Gao Zhendong, some people realized that they knew him! Isn't this Comrade Gao Zhendong who works on computers? Why are we looking for him for batteries?
However, the National Defense Working Committee will never cheat them, and they have made up their minds.
"Yinzinc, there are indeed some problems. It is right not to force the choice." Gao Zhendong has no intention of forcing Yinzinc to show off. This thing has inherent shortcomings. If we push it hard, we are cheating ourselves.
Just like lithium sulfur and lithium air, are they stronger? powerful!
But can it be used? In these days, Gao Zhendong feels that even mentioning it is a sin.
Forget about those things this year, the solution to lithium dendrites will not be solved for decades, and it may be short-circuited after a few charging cycles.
Seeing that Gao Zhendong agreed with his own inference, the comrades from the Ministry of Chemical Industry were very happy. In any case, the first step was that the experts recommended by the National Defense Work Committee recognized their own judgments. This sense of recognition was important to the technical staff. It's very cool.
"Then what are you leaning towards now?" Gao Zhendong smiled.
"Cadmium-nickel battery!" As expected, cadmium-nickel batteries are already available these days, and their use has begun to be promoted in China.
The comrades from the Chemical Department were obviously experienced in reporting. They gave the reasons before Gao Zhendong asked.
In addition to basically meeting other requirements, the most important thing is that the energy density of cadmium-nickel batteries is 0.5 to 1 times higher than that of lead-acid batteries!
Of course, how much higher it is depends on the specific plan. In short, there is no doubt that it is superior to lead-acid.
Gao Zhendong smiled and said: "Well, this is a good idea. There is only one problem that is a little more troublesome. How do you solve the memory effect?"
The memory effect of nickel-cadmium batteries is extremely notorious, and even some weird habits when using other batteries later were left behind by nickel-cadmium batteries at this time.
The key question is here.
"According to the working status of the satellite, it is best to use float charging to ensure that power is always available when possible. But this will conflict with another characteristic of cadmium-nickel batteries, the memory effect."
To put it simply, float charging means charging a little bit. This method is used on cadmium and nickel, and it can basically kill the cadmium and nickel quickly.
And if it is recharged after it is discharged, then when charging, you must consider whether the satellite can shine on the sun. If it cannot, 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 have the luxury of charging our management program and controlling the direction of other comrades' solar panels. Arrange a separate computer to run it.”
Yes, I almost forgot, the young chief engineer in front of me also made the microcontroller. Neither the National Defense Work Committee nor the 12th Machinery Department concealed this matter.
"Well... this is a good idea, but too complex control is not good. For automatic control, to complete a specific function, my tendency is that the control system is as simple as possible."
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Although I don’t know where Gao Zhendong got the confidence to speak so loudly, he was right.
"General Engineer Gao, what is your suggestion?"
"Well, let's make a new battery. I have already made a principle battery. The charge and discharge characteristics are not bad. The energy density is 30% to 50% higher than that of cadmium nickel. The number of charge and discharge has been tested up to 500 times, and it is still normal. Yes, we are still testing.”
"General Engineer Gao, it's impossible! Is this thing about to catch up with the energy density of silver-zinc batteries?"
"It's still a bit worse, but it's more reliable than silver-zinc. Of course, compared to cadmium-nickel, it has one of the biggest advantages, that is, the memory effect is much lighter!"
"What kind of battery is it?" The interest of the comrades in the Chemical Department was completely aroused! But he would never have guessed what kind of battery this thing was, because this battery had not been invented until this time.
"Ni-MH battery!" Gao Zhendong laughed.
(End of chapter)