"By the way, there is one more thing."

After the meeting, Wei Qingfan was about to leave when Xiao Jiasheng suddenly said, "About the fast charging plan for mobile phones."

Wei Qingfan sat down again, motioned for others to leave, and asked, "What's wrong?"

Based on the low voltage and high current direction given by Wei Qingfan, the company's first-generation fast charging solution adopted a 5v*2a solution. It is currently working with the Jinjiu 2 engineering machine for safety verification and improvement. The second

Alternative solutions are under development.

"The R&D team has proposed a new plan."

Xiao Jiasheng explained, "They speculate that when the voltage reaches about 10v, there will be a bottleneck for fast charging of mobile phones. When the current reaches about 5a, it should also reach the bottleneck. In this case, they assume that we will reach 50w fast charging power in a few years.

.

"Because Mr. Wei required that subsequent fast charging solutions be compatible with the previous generation, they reversed several solutions. From a compatibility perspective, it would be better for the second generation to increase the voltage, so in addition to the original 5v*3a 15w solution

In addition, a 9v2a 18w plan was proposed..."

Because he was worried about what would happen after the rebirth plug-in disappeared, Wei Qingfan had been working hard to avoid the situation of overthrowing the situation. To this end, he even consciously used his "majesty" to exchange for everyone's enthusiasm and encourage different voices.

Therefore, in the fast charging plan, although he gave the direction of low voltage and high current, he has also been emphasizing that there are other ideas that can be proposed.

Different mobile phone manufacturers have a long history of developing different charging protocols. For safety reasons and to have a minimum charging standard when the protocols do not match, the USB Alliance has stipulated the standards very early. The USB2.0 protocol stipulates that the standard voltage is 5V.

Maximum current 0.5a, total power 2.5w.

Entering the era of smartphones, the charging power is too slow, and smartphones all use standard USB interfaces. Therefore, the USB Association supplemented the BC1.2 charging protocol in October 2010, increasing the maximum current to 1.5A.

, the power is increased to 7.5w.

Subsequent different versions of charging protocols are basically developed on this basis.

At this time, smartphones all use micro usb interfaces. There are 5 pins in this interface, only one of which is used for charging. The maximum safe current of this pin is 2a.

Wei Qingfan already knew these things, and he also knew that Qualcomm would soon propose a 9v*2a 18w fast charging solution, but he also knew that the type-c interface would be coming in mid-2013, and he would be able to make a breakthrough by then.

The micro usb interface is limited, but there is no way to tell.

He originally proposed a low-voltage solution. On the one hand, he wanted the 5v*2a solution to be implemented as soon as possible. On the other hand, he wanted to follow Oppo's original route of directly modifying the micro USB interface and adding an additional charging interface.

The original saying of Oppo R7 that "charge for five minutes and talk for two hours" was achieved by modifying the micro USB interface to achieve 20W fast charging of 5V*4A.

In the other direction, Huawei at the time quickly changed to the type-ate9 and also achieved a 22.5w charging solution through the 4.5v*5a solution. Then in 2018, it came up with a 10v*4a 40w super fast charging solution.

.

Everyone has switched to type-c interface. Especially after the emergence of charge pump technology, high voltage and high current solutions have become mainstream. Fast charging power has developed to 100w, 120w or even higher, but the mainstream is still 50w.

Around 60w, the slight difference is just a propaganda, the real charging power is even lower, and most of them are "five-second real men", which means the power is lowered instantly.

Wei Qingfan listened to Xiao Jiasheng's speech and asked: "What about the safety if 9V voltage is used?"

The standard voltage of the general lithium batteries used today is 3.7v, and the full voltage is 4.5v. Many people claim that the 5v voltage is actually not reachable at all. The 9v solution has two standard voltages.

Xiao Jiasheng would put forward this plan, and the R&D team naturally had an idea and immediately replied: "Use an inductor to adjust..."

Wei Qingfan immediately realized that this was basically the idea of ​​Qualcomm's 18W fast charging solution, which also used an "inductor" to adjust. Simplified and simplified, it was adjusted by using the characteristics of the inductor that does not allow current mutations to ensure safety.

This principle is just "coupled" with the principle of the later "charge pump". The core of the charge pump is the capacitor, and the characteristic of the capacitor is that it does not allow voltage mutations.

Wei Qingfan felt like he was stabbed in the back by his high school physics knowledge. He patted his head, thought for a while and said: "Then let's do research and development first, research on both sides..."

"good."

Xiao Jiasheng nodded in agreement. Although he knew that Wei Qingfan would most likely give such an answer, he still breathed a sigh of relief when he actually heard it.

Even if "disobeying" your boss has happened several times before, it does not mean that it will be safe and smooth the next time.

According to this idea, after switching to the C port, there is a high probability that the charging power can reach more than 20W. Then we have to get a C port low-end version, both 18W and 10W, and delegate it to other models.

But this one is relatively simple.

After getting rid of this episode, Mr. Wei was finally able to return to the office. When he passed by Jiang Qinghuai's office, he saw no one at her desk. He went back to his office and saw Secretary Jiang cleaning up in his office. There were some things on his desk.

Two stacks of documents.

"so much?"

Wei Qingfan was a little depressed, "How many things are there?"

"Half a month, what do you think?"

Jiang Qinghuai was cleaning the cabinet for him, wiping the collected mobile phones and books one by one, and then carefully put them back to their original places, "The pile outside is for reading, and the pile inside is for signing... You sign slowly

Bar."

This chapter is not over yet, please click on the next page to continue reading! "Okay, as ordered..."

Wei Qingfan sighed and sat down at his desk. He didn't remember to do any work. He took out his cell phone and looked at his unread messages.

The work content was directly filtered by him, and he first looked at the two women.

Li Miaoyu: "I'm out of class!"

Li Miaoyu: "Where should we eat at night?"

Wei Qingfan patted the documents on the table, sent them to her, and typed:

"Mr. Wei is still working hard."

"Just make up your mind. I believe it tastes wonderful."

Look at what Li Wanyi sent again: "Miaomiao is going to have a dinner party tonight, please ask Jiang Qinghuai to come with her."

Wei Qingfan: "Why am I calling?"

Wei Qingfan: "I want you to scream."

Li Wanyi: "Then stop barking."

Wei Qingfan: "???"

Wei Qingfan: "It would be boring if you don't shout. Let's just scream."

Wei Qingfan: "You called."

Li Wanyi: "Then let Miaomiao scream."

Wei Qingfan: "That's okay, either of you can call me."

After sending it, Li Miaoyu also replied:

"I'm already home, so you didn't reply until I got home."

"Then work hard and make money."

Wei Qingfan: "I know, make money to support your family, and you can't live up to my family's wonderful beauty."

Li Miaoyu: "It rhymes quite well, very conscious."

Li Miaoyu: "I'll drive to pick you up later, okay?"

Wei Qingfan: "No, I don't dare."

Wei Qingfan: "You dare to go on the road by yourself?"

Li Miaoyu: "I don't dare, but your company is not far away, and I will go now, there are few cars."

Wei Qingfan: "There are a lot of cars now."

Wei Qingfan: "But it's okay. You can also drive here. Just go slower. It's okay to crash. Don't hurt anyone."

Wei Qingfan: "It's a pity that you had to change to a BMW at that time, otherwise you should have bought a more expensive one so that others would not dare to hit you easily."

Li Miaoyu: "The BMW 750 is also very expensive. Do you really think that the streets in Beijing are filled with millionaire luxury cars?"

Li Miaoyu: "Besides, I'm driving well, why did you hit me?"

Wei Qingfan: "Just in case, just in case."

Li Miaoyu: "Also, why did you ask me to call you Qingqing again? Then the senior sister scolded me again."

Wei Qingfan: "Why do I scold you?"

Li Miaoyu: "She is a bad woman. She doesn't need a reason to scold me."

Li Miaoyu: "Last time I told Qingqing about Duce Safari Park, she scolded me."

Wei Qingfan was a little funny, so he typed and asked: "Why are you scolding you?"

Li Miaoyu: "It's too much to say that I have a bone in the back of my head and that my head can't control it!"

Wei Qingfan: "Hahahahaha"

Wei Qingfan: "Then don't say it next time."

Wei Qingfan: "It's okay to shout about eating, everyone is used to it."

Li Miaoyu: "Then I won't shout, I will ask you to shout."

Wei Qingfan: "It's okay, just scream."

Li Miaoyu: "Don't bark."
To be continued...