First of all, don't confuse concepts. HUB and USB interface are two different things, but USB HUB is inserted on the USB interface.

The computer USB interface 2, USB3.0, represents the USB specification on behalf of the computer motherboard, representing different speeds, and the 3 interface is much faster than the 2 interface. The maximum transmission bandwidth of USB2.0 is 480Mbps (i.e. 60MB/s), while the maximum transmission bandwidth of USB3.0 is as high as 5.0Gbps (500MB/s).

Again HUB, the Chinese name is called the hub, the image point, called the USB expander, can be a USB interface on the computer, extended to a number of USB interfaces, easy to have a number of USB equipment players.

Why use HUB, many computer USB interface is insufficient, or distance is too close, conclusion a device, universal USB equipment will not be able to get in.

What is the difference between the USB interface on the computer and the interface on the HUB divider?

The USB hub is the USB divider, which is to separate a USB interface from a computer to multiple USB ports so that more USB devices can be connected. There is no big difference between them.

USB hub is divided into three types: active, passive and hybrid.

Dynamic: the function of regenerating and amplifying the signal on the connected network medium, the length of the connected medium can reach the maximum effective length, and the power is needed to work. Most of the HUB types are available for this purpose.

Passive: as a connector, it can work without power supply, and it is rare in the market.

Hybrid: it can connect various types of cables, such as shaft and twisted pair.

The current size of the interface on the computer's USB interface and the HUB splitter is different from the signal fidelity. The USB interface on the computer is stable, the signal attenuates little, the interface current on the USB c dock divider will be smaller, and the attenuation of the signal is larger than the USB of the computer. The attenuation of USB signal is larger with the extension of the transmission line.

It is one of the necessary products for outdoor travel to start the car when the automobile emergency start power is used for the car loss or other reasons that can not start the car. At the same time, the LED high light emergency lighting is one of the necessary products.

1, the vehicle car jump starter can fire all the cars exported by 12V batteries, providing emergency rescue services.

2, standard LED super bright white light, flicker warning lamp, and SOS signal lamp, travel travel good helper;

3, auto emergency start power not only supports auto emergency start, but also supports a variety of output, 5V output (supporting mobile products such as mobile phones), 12V output (supporting routers and other products), 19V output (supporting the vast majority of notebook PC products), increasing the wide application of life.

4. The high performance polymer lithium ion battery is built in the emergency starting power of the automobile. It is not the ordinary lead-acid battery. The lead-acid battery is large and heavy. It is not conducive to the carrying and use of the battery. It is also not conducive to the application of life.

5, the car emergency start power supply has long service life, charge and discharge cycle can be more than 500 times, full of electricity (electricity display 5 grid) can start the car 20 times.

6, the amount of electricity required to be more than 3 grid can give the car a fire, so as not to burn the car to start the car jump starter power bank mainframe, remember that the charge is.

USB car charger: usually referred to as USB car charger. It takes advantage of the versatility of USB to be widely applied to various charging interfaces. Then combine the 12V DC and 24V DC to USB and the common DC 5V voltage of each charging appliance. This makes it possible to use the standard power supply on the car and the USB interface to charge the DC 5V appliances. Such as: mobile phones, MP3, navigators, game machines and all other 5V DC appliances.

Car Charger Working principle

First of all: USB car charging must comply with a principle. For the battery charging of small consumer electronic devices, the USB port is an economical and practical power source. To fully comply with the USB 2 specification, the load connected to the USB port must be capable of two-way communication with the host. The load must also meet the power management requirements, including low power mode, and facilitate the host to determine when to draw large current from the port. Although some compatible systems can adapt to most USB hosts, sometimes unexpected results occur. Only with a good understanding of USB specification requirements and load expectations can we achieve a good balance between specification compatibility and load complexity.

Therefore, USB car charging, from interface conversion to voltage conversion, and current power requirements match the needs of electrical appliances. Sometimes you will encounter the USB you bought and cannot charge your appliance, so there may be a matching problem. For example, whether the electrical voltage you use is USB DC 5V voltage. If the voltage is correct, that is, your electrical power may be larger. USB car charging power may not match, there may be no charge, or insufficient electricity. At this point, it is necessary to confirm whether the charging current is large or small.

USB is based on the above factors: it first turns the power supply DC 12V or DC 24V into DC 5V in the car, and then transfers the output of DC 5V to the corresponding electrical appliance with the unified interface of USB. Based on the different electrical power, the power of dual USB car charger is different, which is different from that of USB.

USB car charger specification

USB car is filled with common specifications: output: 5V DC 500mA; 5V DC 700mA; 5V DC 1000mA; 5V DC; it can be found that the current has a variety of specifications after understanding the voltage of its specification output. The different current specifications are easy to use and choose to be applied to different electrical appliances. Such as: the previous mobile phone is basically 500mA current; but with the development of the times, mobile phone, game mobile phone, music, Internet mobile phone and so on, its power is big. So the charger needs a relatively large current. The different specifications of the USB car charger allow users to choose the appropriate matching specifications.

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Since last September Apple conference, the discussion on wireless charging has never stopped. One of the most important reasons is that Apple has released a 7.5W wireless fast charger AirPower at the same time, but it has been in a difficult state, and as a third party accessory manufacturer, it is also very difficult to attack apple 7.5W wireless fast charging.

AirPower is coming out, apple is also gradually opening up the receiving end to the 7.5W wireless fast charging support, the market has also appeared to support the apple 7.5W wireless fast filling parts, including apple recommended third party accessories brand Mophie, Belkin, also Anker, RAVPower and other well-known charging accessories brand.

At the time, the apple mobile phone system has also been updated to iOS11.3, and many iPhone users are still annoying for the selection of wireless charging parts. On the one hand, AirPower is far away and the price is very expensive. On the other hand, third party accessories are not worried about incompatibility. Whether mobile phone shell will affect wireless charging is doubtful.

Recently, the small editor at the same time got the Mophie, Belkin, Anker three wireless charger, just can give you a contrast test, but also to solve the problems you encountered in the choice of iPhone wireless charger.

Let's take a look at the outer packing of the three products from left to right in order of Mophie, Belkin and Anker. Mophie and Belkin need not be said more. Cook was named by iPhone at the press conference. Here is a brief introduction to the Anker wireless charger, which is a Anker wireless fast charger that supports apple 7.5W on MWC2018, named "PowerWave 7.5 Pad" (hereinafter referred to as Anker).

The three main parts of the wireless charger are round bread appearance. Mophie is a black appearance, the volume is slightly smaller than the other two, and a soft rubber material is used around the body. So no matter how it is used, there is a skin touch. Belkin is a pure white panel, it also uses skin material and a soft silicone antiskid pad in the middle. The edge is a small circular point as a state indicator; the Anker body is on the edge. With gray color matching, the front is a piece of anti skid pad, which is similar to silica gel. It is light grey. It feels the same feeling of skin. The state indicator is also designed at the edge, similar to the shape of "period".

In terms of volume, Mophie is the smallest and Belkin is similar to Anker. Mophie wireless charging parameters, only marked the input parameters, 19V/1.3A; CE and RCM authentication. Anker wireless model A2514, passed FCC, RMC, CE, RoHS authentication. In addition, we can see that in the three wireless charger, only a number of small holes are designed on the back of the Anker. This is because the Anker wireless charger is filled with the active fan, and the active cooling fan can cool down in the process of charging the mobile phone to ensure that the charger and the hand machine do not overheat so as to reduce the charging power. In order to ensure long time high power charging, the purpose of wireless fast charging is achieved.

Of course, it is far from enough for wireless fast charging to rely solely on the cooling fan, and the efficiency is also a big factor, so the internal components of the product are also very important.

In short, in terms of appearance, the three products have their own strengths and trade-offs. However, as a wireless charging component, the three products in the mobile phone charging safety is still more in place, with the desktop, and mobile contact with the mobile phone are anti-skid processing, can effectively prevent the mobile phone in the charging process because of some small vibration slipping. If the power adapter is removed, the portability is good, even if the Anker wireless charger with built-in cooling fan can still maintain a thin appearance.

After talking about wireless charging, look at three power adapters that are equipped with wireless charger. The power adapters of Mophie and Belkin on the hand are all British gauge plugs (also have national standard), Anker is the US regulation plug, and is compatible with the national standard. It is necessary to point out that because of the fixed DC voltage input of the two Mophie and Belkin chargers, the power adapters are all customized products, and the interchangeability is poor. And Anker is the QC3.0 fast charging standard charger, the interchangeability is strong; in addition, the charger also uses Anker's own IQ intelligent identification technology to support the APPLE2.4A charging protocol. So, even if not with the use of Qi wireless charger pad, it can be used directly for iPhone, millet, SONY, Samsung and other brands of mobile phone fast charging, very practical.

For charging cable, Mophie line length 155cm, Belkin line length 150cm, Anker line length 90cm; Mophie, Belkin are circular interfaces, Anker Micro USB interface. Anker this charging line has enough materials, and the diameter of the wire is coarse, and the Anker data line is used for the design of water droplets. It has strong bending resistance and durability. It is worth mentioning that the Anker charging cable is equipped with a magic ribbon line, which is more intimate. Having said so much, the appearance of the three products has basically been summed up. Next, we will look at the actual performance of the products through a series of tests.

summary

1, in the aspect of design, as the few parts on the market, Mophie, Belkin and Anker are designed with flattened appearance and easy to carry. Three products of the product wireless charger use a lot of anti-skid materials, and the part of the contact with the mobile phone are soft rubber, in the process of charging the cell phone will not be scratched, and will not cause the mobile phone to slide because of the midway shock.

2, the actual charging test, the three products all support the mobile phone at any angle charging, that is, charging, high sensitivity, supporting the mobile phone with the shell charging, the actual use of the experience is very good. Anker built-in active cooling fan, the control of temperature in the charging process is better, especially after 15 minutes of charging, the temperature advantage is more obvious, and the charging speed of the mobile phone is also obviously improved. When charging the iPhone 8 Plus, the overall charging time of Anker is at least half an hour faster than that of Mophie and Belkin.

3, charging accessories, three wireless charger are equipped with power adapter, users do not need extra preparation. However, it is necessary to point out that Anker is a more common QC3.0 charger and MicroUSB data line, which is more interchangeability than Mophie, Belkin, and more practical.

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We surveyed more than 1000 readers and added our own research findings to the criteria for selecting the best USB hub. A great USB hub must have a USB 3 port, and there should be a dedicated power supply. It requires reliable, practical design, compact, and (for portable hub) light. Each port's LED indicator and a decent warranty are also useful.

The cost of USB 3 hub is often higher than that of USB 2 Center, and the 3 standard has 2.4 GHz interference. However, we chose to focus on the USB 3 hub because the USB 2 standard was old - it was launched in April 2000, and USB 3 made its debut in November 2008, many times slower than 3. For example, our favorite desktop hard disk drive transfers about 150 megabytes per second on the USB 3 connection, but on USB 2, its maxes is only 40 MB- if you think you will always need to insert USB 3 – capable external hard drive or flash drive into the data hub, and you will need USB 3 The extra speed provided by the.0 hub.

Dedicated power supply is necessary for most hubs, but not all. The kind that doesn't need it at a certain time. To explain why, we first need to discuss how power flows through the USB hub. According to official USB 3 specification, each USB 3 port must provide 900 ma current at 5 volts, or 4.5 watts. If your USB 3 hub is powered only by the USB 3 port of the computer (in other words, there is no dedicated power line or adapter), this means that there are four devices in your theory running on the amount of power normally provided to one. Such an arrangement may cause the device to lose power and disconnect from the computer, which may cause damage to the driver and data loss.

However, it is important to recognize that this theoretical setup has great flexibility. The 900 ma current requirement of USB 3 port is a minimum value instead of a fixed level, and manufacturers usually provide more power for their hub ports. The power consumption of the device varies greatly due to the USB type hub and the operation you do at a given time. For example, in the user's manual, Anke provides the following estimates of power consumption according to the device: the mouse consumption is about 100 Ma, the keyboard uses up to 500 mA, and the portable USB 3 hard drive consumes 900 ma.

These are very generous estimates designed to encourage caution in order to avoid overloading your hub by accident. When you first insert them into a hub and transmit data, the device usually gets the maximum power, but rarely draws the maximum theoretical value, especially during the extension period. However, it is a wise idea to use a dedicated power line or adapter, if you don't want to take the risk of careless damage to everything on your hard drive; for a USB hub with more than 4 ports, a dedicated power line or adapter is absolutely necessary. (for a travel friendly four port USB hub, this is not entirely necessary, but the unpowered installer needs to be careful to avoid the greater power of the device to try than the USB 3 port of a portable computer. Here we will discuss this topic in more detail.

In addition to the minimum power, we know from our study of USB chargers that people prefer ports that can recharge mobile phones and tablets faster; an informal Twitter survey of readers confirms this. So we look for a hub for high speed charging ports, a function that requires an external AC power supply, and we end up focusing on the power model in addition to the portable hub.

With these power requirements, we eliminate any USB hub and do not have enough juice to give full play to all its ports. For example, we have seven USB 3 ports and three 2.4 amps charging ports at the top. According to the USB 3 specification, this means that the hub may require up to 47 watts of power to make all its ports in its maximum theoretical upper limit - because it includes a 12 volt, 5 ampere (60 Watt) power, it gets enough electricity, and its all ports are at its maximum upper limit. Many hubs that do not have enough power are not significantly smaller,

lighter or cheaper to make up, so we exclude these models.

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