In order to further increase the screen area, Huawei Samsung launched a folding screen mobile phone. Although effective, manufacturing is not only costly, but also difficult.

In particular, Motorola, a fan of cold food, has proposed a folding screen mobile phone, which is naturally a folding screen, which is perfect. But the cost of making screens is still high.

In order to further increase the air gap surface area (proportional to the torque), scholars (such as Qu Ronghai of Huake and Christopher Lee of Nanyang Technology) proposed a double stator structure. Although effective, manufacturing is not only costly, but also difficult.

In particular, some scholars who like to stir fried rice have proposed that the axial flux motor, which has existed for a long time, is not naturally suitable for double air gap. It is simply perfect! But manufacturing costs are still high.

Some phones have a screen on the front and a screen on the back. However, the power consumption is so large that it is inexplicable.

There is a kind of motor called double mechanical port motor, which has two rotors, one rotor inside and one rotor outside. For example, this kind of motor can replace planetary gear in theory. But it's inefficient. What's the picture?

Huawei believes that the "4G band" between the mobile phone and the base station is too low, and it can move forward to the "5g band" of higher frequency band. (for 5g science popularization, I recommend the video released by IEEE spectrum on YouTube two years ago)

There are many problems with 5g technology after the frequency is increased.

Some of the problems are already existing, but now they are more serious. For example, 4G has higher frequency than 2G, and the wave length will lead to poor penetration. Now the penetration is even worse. In order to ensure that your mobile phone can receive the signal, a stupid way is to raze the trees and flowers of high-rise buildings.

At present, the switching frequency of silicon elements used in the inverter for motor power supply is too low. The emergence of wide band gap (not the broadband used in your home, but wide gap band) switching elements (such as silicon carbide, SiC) has realized the further improvement of inverter carrier frequency.

There are many problems in the broadband gap technology after the switching frequency is increased.

Some of the problems are already existing, but they are more serious now. For example, compared with thyristor, the chopping frequency of MOSFET is higher, the DV / DT is larger, and now it is larger. For safety, a silly way is to crazy increase the thickness of winding insulation material.

A motor manufacturer claims that its products can achieve accurate position servo control without coding disk. In fact, the hall element is hidden in the motor casing, and the coding disk is replaced by Hall element, and the accuracy is also reduced. Kalman filter is needed to supplement the waveform.

Xiaomi and oppo have launched the invisible front camera, which can't be seen in normal use. It's just that when taking photos, due to a layer of glass, it's a little sticky, so it needs to be corrected with software.

The essence of mobile phone is to transfer information between two devices by modulating signal.

Most mobile phones support Bluetooth protocol.

A Huawei mobile phone supports not only Bluetooth communication, but also near-field communication (NFC) with higher frequency band.

Google has a modular mobile phone, you can remove the Bluetooth module, install the NFC module, and then, only support NFC.

The essence of motor is to produce magnetic field to transfer energy between stator and rotor.

Most motors support the use of fundamental magnetic fields to produce torque.

A vernier machine not only supports the use of fundamental torque, but also supports the use of higher frequency tooth harmonic magnetic field to generate torque.

Linear motor is highly recommended to be modular. Because it must be fractional slot, it only supports torque generation by harmonics, and fundamental wave is not used.

The battery of Samsung note 7 will explode, but no one seems to have been killed. As a result, note 7 is not allowed to be taken on the plane.

Samsung has launched a fire-fighting vase, which usually contains flowers. When note 7 explodes, it can extinguish the fire by throwing the vase on note 7 instantly.

The Tesla Model s battery will explode, but fortunately the owner is not in the car.

The founders of ABB or Siemens were kicked out of the company. Later, the company installed and updated the software of frequency converter to reduce the bus voltage, resulting in the decrease of maximum motor speed. After it was discovered, the company launched a capacitor replacement service, but refused to transfer the software back.

ABB or Siemens insist on using advanced switching elements for their own power converters. In this way, when new products are launched, it can be said that the latest power converters use wide band gap switching elements. Sounds great, doesn't it? The expensive thing is a cent of goods! However, the fact is that this wide band gap switch element is used in the rectifier part, and the inverter part has not changed. You have to use the motor as a generator to give full play to its strength.

After Jobs's death, Apple's mobile phone actively reduced the operating frequency of the processor through software updates, causing the phone to jam, suggesting to buy a new phone. After it was discovered, it was unrepentant to launch a battery replacement service, which did not support operating system degradation.

Apple insists on using the best processor for its products. In this way, when launching new products, it can be said that the latest Apple computers use Intel's latest i9 processor. Sounds great, doesn't it? The expensive thing is a cent of goods! However, this computer has to run in the refrigerator to keep the processor running at high load. If you turn off the overheat protection system, this is a light iron plate burning device.

Some mobile phones support wireless charging, that is, the charging line is replaced by coil (inductive type) or capacitor (capacitive type).

Users have higher and higher requirements for the charging speed of mobile phones, but the speed of wireless charging is also higher