1、 Preface

As the main source of green energy, solar power generation technology is usually used in large power generation systems, which are connected to the power grid after energy storage by batteries and inversion. In addition, there are also corresponding applications in the power supply of some small embedded devices. For example, Mobike uses solar panels to charge batteries. But in the field of mobile digital, there are basically no decent products to support it. Recently, however, Beijing Times Minxin Technology Co., Ltd., a subsidiary of China Aerospace, launched a product - Sun Cube, which focuses on the mobile power market for charging mobile devices. I'm lucky to win the lottery@ Love to play computer games We would like to thank you for the opportunity to try out the "Sun Cube". Today we will learn about this black technology product.

2、 Unpacking

The outer package of the product uses a thick hard paper shell, and a large China Aerospace logo on the upper right corner of the front shows that the product is from a "rich family". Under the product name Sun Cube, "a solar mobile power supply that can be freely spliced" accurately describes the characteristics and functions of the product.

The specifications of the product are described on the back of the packaging box. The main parameter is output 5.2V 0.9A, which is 5.1W in total.

Open the box and see the logo paper sticker for @ machine trial. Below is the product manual. The cover and bottom of the packaging box are both provided with thick soft adhesive protective layer, which can play a good role in protecting the product.

The user manual is not too much. It uses very thick coated paper, which describes the overview and operating instructions of the product. In addition, the precautions and performance indicators are also very detailed.

Take away the manual, you can see the true face of the sun cube.

Most of the mobile power supply is solar panel, and the external plate is the back plate of the solar panel. It is similar to the glass texture, and it is very comfortable to feel. It is said that it is the Kevlar back plate.

Each of the four sides has two metal magnetic contacts, which are connected in series and parallel with the instant noodles. The rest of the left part is the metal texture sandblasted shell, which is the circuit board.

The layout on the back is the same as that on the front, and the manufacturer and product model are marked. The model is M5100.

A LED screen is embedded in the window of the metal texture shell to display the current information.

At the four corners of the mobile power supply, there is a hole. This hole is a hanging hole, which can be hung by threading.

On the top of the side, there is a standard USB Type A interface for power output.

From the side view, the power supply is very thin, which is thinner than the mobile phone. This is the thickness of two panels.

It requires some skills to disassemble two groups of panels. Slightly separate two layers of panels on the side, and then pull your hands up and down to separate them.

The real solar panel is inside after being separated. The two panels can be automatically combined after being opened and flattened. Magnetic contacts play a key role in this process.

It is still firm after being combined. This process is actually equivalent to paralleling two panels.

In this process, it was found that the gap at the junction of the metal texture shell of the mobile power supply was still quite large, and there was still room for further improvement of the precision or process of the abrasive tools.

3、 Disassembly

Due to professional habits, I really want to know what scheme is used for internal circuit boards. Then let's simply disassemble it.

The panel shell uses 1.5mm socket head cap screws. This specification is relatively rare in China. I didn't have proper tools in my toolbox, so I went to the hardware store to buy a set of socket head cap screws. The minimum specification is exactly 1.5mm. It can be disassembled by rotating counterclockwise.

The removed screws can be placed on the magnetic panel contacts to prevent them from being lost, and can be just absorbed.

First, open the secondary board without LED screen. The circuit board inside is very simple. The circuit board uses six elastic metal contacts to connect with the solar panel. Both ends of the PCB board are provided with an opening for fixing and positioning. There are only some capacitance and resistance devices on the A side. The most prominent one is the 5.5V 0.1F supercapacitor of KAMCAP on the left, which should be used as a buffer for electric energy.

Two chips with the model of IV0300D were found on the B side of the PCB, and no relevant information was found on the Internet. It should be the MPPT (maximum power catch) power management chip independently developed by the manufacturer. I learned about MPPT when I was working on a power supply scheme, but I still have some technical content. Two miniature inductors L1 and L2 should be used together with these two chips.

Next, disassemble the motherboard with LED. The motherboard and solar panel are also connected by several metal elastic contacts. The PCB of the motherboard is divided into two parts. One part is a pure USB interface board, and a USB TypeA mother seat is welded. The other PCB is the main control part. The two parts are connected by three wires.

On the A side of the motherboard, the largest chip VK1024B is a LCD driver, and the 7533-1 is a 3.3V output three terminal regulator. The five pin chip with screen printed RC1K is an operational amplifier of TI.

There are also two IV0300D chips on the B side of the motherboard, which are also used for power management. There is a small LCD screen in the middle.

The largest 20 pin chip is the main control MCU of the whole system. The chip model is PIC16F1509, which is a 16 bit microcontroller of Microchip. Although the performance is average, the main MCU as a mobile power supply is enough.

Through disassembly, it was found that the materials used for the mobile power supply were regular, and the PCB board and welding processes needed to be further improved.

4、 Trial

After a certain understanding of the product, the next step is the practical application. After splicing the two panels, place them in a sunny place. After several decades, the LCD will light up and display a current of 0.00A.

At this time, try connecting the USB cable to the iPad, and the charging current is 0.05A.

Then take it outside and adjust the angle continuously to make the panel face the sun, and the charging current reaches 0.38A. This is the limit. It's not that the efficiency of solar panels is too low. It's really the sunny day in my city in recent days. The sky is also gray. The weather is really not good. At the same time, this also exposes a major limitation of the solar power charger. The availability of solar mobile power will be directly affected by the weather and the environment.

5、 Summary

Through disassembly and trial, I got a general understanding of this solar power charging bank. It has many advantages, such as green energy, which can be charged as long as there is sunshine. It is very environmentally friendly and portable. However, there are also some shortcomings. First, the mold is relatively not fine, the gap size is irregular, and some places are large. Secondly, the charging efficiency is relatively low, especially when the weather is not so good, and the full power output cannot be achieved. Today, the battery capacity is increasing, it may take a long time to fill the phone, which can only be used as an emergency. In any case, the introduction of solar mobile power is also a great attempt of Time Minxin Technology. I hope that the product will become more perfect and practical after several iterations.

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