My favorite mobile phone NOKIA 6500, which was bought about half a year ago, was not initially charged. Were held renovation work, after which the phone worked for about a month. The main problem was that the phone had to be charged using a universal charger, and it is inconvenient to constantly remove the battery.

It was in this connection that I decided to install a wireless charging system on my phone. The system was assembled according to its own idea within a couple of hours.

How wireless charging works

The principle of operation of such a wireless charging scheme is quite simple. The role of the charger is played by the transmitting circuit, the device itself consists of two circuits - a transmitter and a receiver.

The receiving circuit (flat coil) is located in the phone itself, the transmitter is made in the form of a small stand, inside which the transmitting coil is hidden.

Wireless charging circuit

Electricity is transferred from one circuit to another by induction, the current generated in the second circuit is first rectified and fed to the battery. Literally any low-power Schottky diode can be used as a rectifier.

Do-it-yourself wireless charging assembly begins with the transmitter.

Transmitter

The transmitter circuit is simple and straightforward. Conventional single transistor block generator circuit. The frame for winding the transfer coil is at your discretion. It is advisable to take a frame with a diameter of 7-10 cm. We wind 40 turns of copper wire with a diameter of 0.5 mm on the frame. The winding is tapped from the middle. First, we carefully wind 20 turns, then we twist the wire, make a bend and wind the remaining 20 turns in the same direction. Is everything clear with the coil? Let's move on.

The transistor is absolutely any, I tried both field-effect and bipolar, with field-effect it charges a little faster. You can use field keys of the IRFZ44 / 48, IRL3705, IRF3205 series (I indicate only those that I used myself), but you can put literally any. Of the bipolar ones, domestic ones can be used: KT819, 805, 817, 815, 829. The choice is not critical. You can also use direct conduction transistors, but in this case you will have to reverse the polarity of the power supply.

The base resistor rating is not critical (22 ohm-830 ohm).

Receiver

The receiving circuit - I was winding for half an hour. The coil is flat, consists of 25 turns of wire 0.3-0.4 mm. It is convenient to wind the contour on a small piece of plastic, the turns must be gradually strengthened with superglue, the work is quite dirty and long. After winding, we separate the contour from the plastic stand on which it was wound. It is convenient to do this with an assembly knife or blade.

In my case, the charging connector on the phone did not work, so I connected the charger directly to the battery. This solution is inconvenient because the sensor will not show that the phone is charging. With the phone all finished, now you need to put the back cover.

Charging time directly depends on the power of the power source, in my case the factory charger experimental phone. The device provides an output voltage of 5V, at a current of 350mA.

Such a wireless charger for the phone works flawlessly, with this arrangement of components, the mobile phone is fully charged in 7 hours, for a long time, but it charges. Charging time can be accelerated only by powering up the circuit - use a more powerful power supply and wind the circuit with a thicker wire.

Content

There are situations when a mobile gadget has almost turned off, and there is no native charging at hand or there is no electricity. Then some knowledge will help solve this problem: a new invention is wireless charging, you can make it yourself. It is convenient to use, even when there is no car charger nearby.

Is it possible to make a charger by hand

The answer to this question is yes. Anyone who has an elementary understanding of the properties of wires and current can make it. Before you build such a structure with your own hands, you need to take care of the presence of all materials - a diode and copper wire. Any plastic box, for example, from a CD, can serve as a case. You will also need transistors (bipolar or any other), preferably field ones - they will make the battery charging faster. All other tools are in every apartment, including glue and scissors.

How wireless charging works

The principle of operation of this type of charging is based on induction, the property of a coil to transmit electric current when in contact with a receiver. When connected to any power source, the device becomes a hotbed of perpendicular magnetic field. If you place two coils close to each other, one of them is connected to any power source, the second one will have a voltage of a certain strength and energy for the mobile phone. This effect is possible if these two coils do not touch each other in any way. DIY wireless charging is a reality.

How to charge your phone

Almost everyone can make a portable wireless charger with their own hands, following the instructions. The whole process consists of two parts: making the transmitter ( interior) and receiver (outer part). The first of them is separate, the second is installed in the phone. The convenience of this solution is that you can always take your charger with you.

Transmitter device:

1. In advance, it is necessary to prepare a frame with a diameter of 7 to 10 cm. Wrap about 40 turns of wire (exclusively copper, with a diameter of 0.5 mm) on it, not forgetting to make a bend in the middle after 20 circles. To do this, twist the wire, make a branch and continue winding.
2. Connect a transistor of absolutely any value to the end of the coil and to the tap. If a direct conduction device is used, the polarity must be reversed when connecting.
3. Install in a plastic disc box or any other. Close.
4. The electricity transmission device is ready.

Receiver device:

1. Unlike the transmitter, it has a flat appearance. Consists of 25 turns, while the wire must be taken a little thinner, in the range of 0.3-0.4 mm. Gradually the receiver needs to be reinforced with superglue.
2. Separate the contour from the plastic base on which it was wound using a knife.
3. Connect it through a diode (high frequency silicon is best) and attach it to the top of the battery. A capacitor is used to stabilize the voltage.
4. Connect to the charging connector. In some cases this can be done directly with the battery, but the battery full sensor will not work.
5. Close the back cover of the mobile phone. The receiving device is ready.

To use the charger, simply place your mobile phone on top of the transmitter. In this case, you need to monitor the sensor on the smartphone screen. There is another circuit for this device using a voltage amplifier and a resistor. Such wireless charging with your own hands can also reanimate a mobile phone without electricity, but it is recommended to be used only by experienced craftsmen.

Method 4. External energy storage with a solar battery

Another interesting option. As daylight hours begin to increase, it is important to discuss the benefits of solar energy storage. You will see how to make a portable charger that can be charged from solar panels.

We need:

• Lithium-ion battery of 18650 format,
• Case from the same drives
• 5V 1A voltage boost module.
• Battery charge board.
• Solar socket 5.5 V 160 mA (any size)
• Connection wiring
• 2 diodes 1N4007 (others are possible)
• Velcro or double-sided tape for fixing
• Hot glue
• 47 ohm resistor
• Contacts for energy storage (thin steel plates)
• Pair of tumblers

1. Let's study the basic circuit of an external battery.

The diagram shows 2 connecting wiring different colors... Red connects to "+", black to "-".

1. It is not recommended to solder the contacts to the lithium-ion battery, so we put the terminals in the case and fix them with hot glue.
2. The next task is to place the voltage boost module and the charging board for the battery. To do this, we make holes for the USB input and USB output 5 V 1 A, a toggle switch and wires to the solar panel.
3. Solder the resistor (resistance 47 Ohm) to the USB output, on the back of the module that increases the voltage. It makes sense for charging the iPhone. The resistor will solve the problem with the very control signal that starts the charging process.
4. To make the panels easy to carry, you can attach the panel contacts using 2 small female-male contacts. Alternatively, you can connect the main body and panels with Velcro.
5. We put a diode between 1 contact of the panel and the charge board of the energy storage. The diode should be placed with an arrow towards the charge board. This will prevent the storage battery from discharging through the solar panel.

IMPORTANT. The diode is placed in the direction FROM the solar panel TO the charge board.

How many charges will such a Power Bank last? It all depends on the capacity of your battery and the capacity of your gadget. Remember that discharging lithium drives below 2.7 V is highly undesirable.

As for the charge of the device itself. In our case, we used solar panels with a total capacity of 160 mAh, and the battery capacity is 2600 mAh. Therefore, under direct light conditions, the battery will be charged in 16.3 hours. Under normal conditions - about 20-25 hours. But don't let these numbers scare you. It takes 2-3 hours to charge via miniUSB. Most likely, you will use the solar panel when traveling, hiking, long trips.

Finally

Choose the method that works best for you and build your own portable battery. Such a thing will definitely come in handy on the road or on a trip. There are a lot of advantages of the made device: it is unique appearanceand also a way to get the power that meets your exact needs. A portable battery can be used to charge not only phones, but also tablets, wireless headphones and other small gadgets.

Making a solar USB charger for your phone with your own hands is one of the most interesting and useful projects on. Making a homemade charger is not too difficult - the necessary components are not very expensive and are easy to obtain. Solar USB chargers are ideal for charging small devices like your phone.

The weak point of all homemade solar chargers is the batteries. Most are assembled using standard nickel-metal hydride batteries - cheap, affordable and safe to use. But unfortunately, NiMH batteries have too low voltage and capacity to be seriously considered as a quality, the power consumption of which only grows every year.

For example, the iPhone 4's 2000 mAh battery can still be fully recharged from a homemade solar charger with two or four AA batteries, but the iPad 2 has a 6000 mAh battery that is no longer so easy to recharge with a similar charger.

The solution to this problem is to replace nickel-metal hydride batteries with lithium ones.

In this tutorial, you will learn how to make a solar USB charger with a lithium battery with your own hands. First, compared to this homemade charger, it will cost you a lot. Secondly, it is very easy to assemble it. And most importantly, this USB lithium charger is safe to use.

Step 1: Required components for solar USB charging assembly.

Electronic components:

• Solar cell 5V or higher
• 3.7V Li-ion battery
• Li-ion battery charging controller
• USB boost circuit direct current
• 2.5mm Panel Mount Connector
• 2.5mm plug with wire
• Diode 1N4001
• The wire

Construction materials:

• Insulating tape
• Heat shrink tubing
• Double Sided Foam Tape
• Solder
• Tin box (or other enclosure)

Tools:

• Soldering iron
• Hot glue gun
• Drill
• Dremel (optional, but desirable)
• Nippers
• Wire stripper
• Friend's help

This guide will show you how to make a solar phone charger. You can refuse to use solar panels and limit yourself only to the manufacture of a regular USB charger on lithium-ion batteries.

Most of the components for this project can be purchased from online electronics stores, but the USB DC boost circuit and lithium-ion battery charge controller will not be easy to find. Later in this guide, I'll show you where you can get most of the required components and what each one is for. Based on this, you yourself decide which option suits you best.

Step 2: Benefits of Lithium Battery Chargers.

You may not guess, but most likely the lithium-ion battery is right now in your pocket or on your desk, and maybe in your wallet or. Most modern electronic devices use lithium-ion batteries, which are characterized by high capacity and voltage. They can be recharged many times. Most AA batteries are nickel-metal hydride chemically and cannot boast of high technical characteristics.

From a chemical point of view, the difference between a standard AA NiMH battery and a lithium ion battery lies in the chemical elements contained within the battery. If you look at Mendeleev's periodic table of elements, you will see that lithium is in the left corner next to the most reactive elements. Nickel, however, is located in the middle of the table next to chemically inactive elements. Lithium is so reactive because it only has one valence electron.

And it is precisely for this reason that there are many complaints about lithium - sometimes it can get out of control due to its high chemical activity. A few years ago, Sony, a leader in laptop battery production, manufactured a batch of low-quality laptop batteries, some of which spontaneously burned.

That is why, when working with lithium-ion batteries, we must adhere to certain precautions - very accurately maintain the voltage during charging. This manual uses 3.7V batteries, which require 4.2V charging voltage. When this voltage is exceeded or decreased chemical reaction can get out of control with all the ensuing consequences.

This is why extreme care must be taken when working with lithium batteries. If handled with care, they are reasonably safe. But if you do inappropriate things with them, it can lead to big trouble. Therefore, they should only be operated strictly according to the instructions.

Step 3: Select a lithium-ion battery charge controller.

Due to the high chemical reactivity of lithium batteries, you must be 100% sure that the charge voltage control circuit will not let you down.

Although you can make your own voltage control circuit, it's best to just buy a ready-made circuit that you can be sure of working. Several charge control schemes are available to choose from.

Adafruit is currently launching the second generation of lithium battery charge controllers with several available input voltages. These are pretty good controllers, but they are too big. It is unlikely that on their basis it will be possible to assemble a compact charger.

You can buy small lithium battery charging controller modules on the Internet, which are used in this manual. I also collected many others based on these controllers. I like them for their compactness, simplicity and the presence of an LED indication of the battery charge. As with the Adafruit, the lithium battery can be charged via the controller's USB port when the sun is out. USB charging is an extremely useful option for any solar charger.

Regardless of which controller you choose, you must know how it works and how to properly operate it.

Step 4: USB port.

The USB port can charge most modern devices... This is the standard all over the world. Why not just plug the USB port directly into the battery? Why do you need a dedicated USB charging circuit?

The problem is that according to the USB standard, the voltage is 5V, and the lithium-ion batteries that we will be using in this project are only 3.7V. Therefore, we will have to use a USB DC boost circuit that increases the voltage to sufficient to charge various devices. Most commercial and home-made USB chargers, on the contrary, use step-down circuits, since they are assembled on the basis of 6 and 9 V batteries. Lower-voltage circuits are more complex, so it is better not to use them in solar chargers.

The circuit used in this manual was selected as a result of extensive testing of various options. It is almost identical to the Minityboost Adafruit scheme, but costs less.

Of course you can buy an inexpensive USB charger online and disassemble it, but we need a circuit that converts 3V (voltage of two AA batteries) to 5V (voltage on USB). Disassembling a regular or car USB charger will do nothing, since their circuits work to lower the voltage, but on the contrary, we need to increase the voltage.

In addition, it should be noted that the Mintyboost circuit and the circuit used in the project are capable of working with Apple gadgets, unlike most other USB chargers. Apple devices check USB info pins to know where they are connected. If the Apple gadget determines that the info pins are not working, it will refuse to charge. Most other gadgets do not have this check. Trust me - I've tried a lot of cheap eBay charging schemes - none of them have been able to charge my iPhone. You don't want your homemade USB charger to be unable to charge Apple gadgets.

Step 5: Battery selection.

If you google a little, you will find a huge different sizes, capacities, voltages and costs. At first, it will be easy to get confused in all this diversity.

For our charger, we will be using a 3.7V lithium polymer (Li-Po) battery, which is very similar to an iPod or mobile phone battery. Indeed, we need a battery exclusively for 3.7 V, since the charging circuit is designed specifically for this voltage.

The fact that the battery should be equipped with built-in overcharge and over-discharge protection is not even discussed. This protection is usually referred to as "PCB protection". Search for these keywords on the eBay online auction site. From itself it is just a small printed circuit board with a chip that protects the battery from overcharging and discharging.

When choosing a lithium-ion battery, look not only at its capacity, but also at its physical size, which mainly depends on the case you choose. I had an Altoids tin box as the case, so I was limited in the choice of the battery. At first I thought of buying a 4400 mAh battery, but because of its large sizes I had to limit myself to a 2000 mAh battery.

Step 6: Connect the solar panel.

If you are not going to make a solar charger, you can skip this step.

This guide uses a 5.5V 320mA solar cell in a hard plastic case. Any large solar panel will do. For the charger, it is best to choose a battery rated for 5-6 V.

Take the end of the wire, split it in two and strip the ends a little. The wire with the white stripe is negative, and the completely black wire is positive.

Solder the wires to the corresponding pins on the back of the solar panel.

Cover the solder joints with tape or hot glue. This will protect them and help reduce stress on the wires.

Step 7: We drill a tin box or case.

Since I used an Altoids tin box for the case, I had to do a bit of work with a drill. In addition to a drill, we also need such a tool as a dremel.

Before you start working with the tin box, fold all the components into it to make sure in practice that it suits you. Think about how best to place the components in it, and only then drill. The locations of the components can be marked with a marker.

After marking the places, you can get to work.

There are several ways to remove the USB port: make a small cut right at the top of the box, or drill a hole of the appropriate size on the side of the box. I decided to make a hole in the side.

First, attach the USB port to the box and mark its location. Drill two or more holes within the designated area.

Grind the hole with a dremel. Be sure to follow safety precautions so as not to injure your fingers. Under no circumstances hold the box in your hands - hold it in a vice.

Drill a 2.5mm hole for the USB port. Expand it with a dremel if necessary. If you don't plan on installing a solar panel, then there is no need for a 2.5mm hole!

Step 8: Connect the charging controller.

One of the reasons I chose this compact charging controller is its high reliability. It has four contact pads: two in front next to the mini-USB port, where DC voltage is supplied (in our case, from solar panels), and two in the back for the battery.

To connect the 2.5 mm connector to the charging controller, you need to solder two wires and a diode from the connector to the controller. In addition, it is advisable to use heat shrink tubing.

Fix the 1N4001 diode, charging controller and 2.5mm connector. Place the connector in front of you. Looking at it from left to right, the left contact is negative, the middle one is positive, and the right is not used at all.

Solder one end of the wiring to the negative leg of the connector, and the other to the negative terminal on the board. In addition, it is advisable to use heat shrink tubing.

Solder one more wire to the diode leg, next to which the mark is applied. Solder it as close to the base of the diode as possible to save more space. Solder the other side of the diode (unmarked) to the middle leg of the connector. Again, try to solder as close to the base of the diode as possible. Finally, solder the wires to the positive terminal on the board. In addition, it is advisable to use heat shrink tubing.

Step 9: Connect the battery and USB circuit.

At this stage, you only need to solder four additional contacts.

You need to connect the battery and USB circuit to the charge controller board.

Cut some wires first. Solder them to the positive and negative pins on the USB circuit, which are located on the underside of the board.

Then connect these wires together with the wires coming from the lithium-ion battery. Make sure you connect the negative wires together and connect the positive wires together. Let me remind you that the red wires are positive, and the black ones are negative.

After twisting the wires together, weld them to the contacts on the battery that are on back side charging controller boards. It is advisable to thread through the holes before soldering the wiring.

Now we can congratulate you - you have 100% completed the electrical part of this project and you can relax a little.

At this point, it is a good idea to test that the circuit works. Since all the electrical components are connected, everything should work. Try charging your iPod or any other gadget with a USB port. The device will not charge if the battery is low or defective. Also, place the charger in the sun and see if the battery charges from the solar panel - this should turn on the small red LED on the charge controller board. You can also charge the battery via a mini-USB cable.

Step 10: Electrical isolation of all components.

Before placing all the electronic components in the tin box, we must be sure that it cannot cause a short circuit. If you have a plastic or wooden case, then skip this step.

Place a few strips of electrical tape on the bottom and sides of the tin box. It is in these places that the USB circuit and charging controller will be located. The photos show that the charging controller was left loose.

Try to insulate everything thoroughly so that a short circuit does not occur. Make sure that the solder is strong before applying hot glue or tape.

Step 11: Place the electronic components in the housing.

Since the 2.5mm connector needs to be bolted, place it first.

There was a switch on the side of my USB circuit. If you have the same circuit, then first check if the switch that is needed to turn on and off the "charging mode" works.

Finally, you need to secure the battery. For this purpose, it is better to use not hot glue, but several pieces of double-sided tape or electrical tape.

Step 12: Operate your homemade solar charger.

In conclusion, let's talk about correct operation homemade USB charging.

The battery can be charged via the mini-USB port or from the sun. A red LED on the charge controller board indicates charging, and a blue LED indicates a fully charged battery.

To all brainworms, Hello! I suppose you all belong to the part of the world's population that uses smartphones, and I think over the past couple of years you have changed them several times to more advanced ones. All "outdated" smartphones have lithium-ion batteries, which are not possible to use in new models, and thus you have good, but useless batteries ... Is this so?

Personally, I have accumulated three phone batteries (and I did not change the phones because of a malfunction of the batteries), they did not heat up or swell, and they can be used to power some gadgets. The average battery capacity after 2 years of use is about 80% of the original, this is the period during which I usually buy a new one. brainsmartphone... And if you think more about the efforts to obtain raw materials, battery manufacturing and transportation costs ...

All things considered, it would be a real shame to let them slowly "die" or just throw them away. In this brain article and video i will tell you how do it yourself to do homemadeallowing to “give new life»Batteries from old phones, that is, to make an external battery for gadgets, aka POWERBANK.

Step 1: Materials

Well, let's start with what you need to create your own external battery. Materials needed:

• lithium-ion battery,
• charging and protection board for lithium-ion batteries, rated for 5V, maximum input current 1A (the less, the longer the "second life" of the battery will be),
• dC / DC boost converter with 5V output and max. 600MA
  wires,
• multiple pin connectors,
• stationery clip,
  a piece of acrylic
• screws,
• and a switch.

You will also need:

• a pair of pliers,
• stripper,
• soldering iron,
• and a glue gun
• and also a drill and a drill.

Step 2: How do the boards work?

First, let's take a look at the charging and protection board for lithium-ion batteries. Its three important functions are charging, overcurrent protection and undervoltage protection.

Lithium-ion batteries are charged according to a specific pattern - when they are almost fully charged, their current consumption is reduced. Brain payment recognizes this and as soon as the battery voltage reaches 4.2V, stops charging. There is a protection circuit at the output of the board to prevent overcurrent and undervoltage. Such protection is already built into modern telephone batteries, but this homemade this board will allow the use of unprotected batteries found in older laptops. The charging current of the board can be adjusted by means of a resistor, and it should be within 30-50% of the nominal battery capacity.

A DC converter converts the DC voltage of the battery into a square wave and passes it through a small coil. As a result of induction processes, a higher voltage is generated, which is converted back to DC and can be used to power 5V gadgets.

Now, more or less knowing what we are dealing with, we can proceed with the assembly itself brainwashing.

Step 3: design

Before you start creating a case for homemade, measure the components and make a drawing. So in my brain organization the battery will be attached with a clerical clip, which is screwed to the case, the boards will be located on top of each other, the input / output contacts will be on top in the upper part of the case, and the contacts going to the batteries in the bottom.

Some batteries have a non-standard position of the polarity of the contacts, so this "non-standard" must be taken into account in our device, that is, add pin connectors. To do this, take the connector with three pins and pull out the middle one, and bend the pins themselves on one side, so that it is more convenient to apply them to the battery contacts. Or take a connector with four pins, the outermost of which connect to the positive terminal, and the middle to the negative, and thus change the polarity of the contacts simply by connecting the battery to the left or right pair of pins.

Step 4: making the case

Now let's start assembling the case. To do this, we take a ruler and mark the lines with a sharp knife, scratching them about 10 times, so that then we do not apply great efforts to the workpiece and no longer use the ruler. After scratching the lines to a sufficient depth, we apply pliers to them and bend the workpiece until it breaks along these lines. Thus "nalomav" all the necessary details brain corpus, we clean them and adjust them to each other. Then we fix them to a stable surface and use a drill to make holes and slots for screws, a switch, inputs, outputs and pin connectors.

Step 5: Assembling the electrical circuit

Before starting the assembly brain equipment we first assemble the electrical circuit, and focus on the presented diagram. A small switch here serves to turn on / off the DC / DC converter.

Step 6: final assembly

Using a glue gun, we glue the boards to each other, and then from one of the body parts. Next, we glue the entire body, and screw a clerical clip to it.

Connect the battery through the pin connector and try homemade In action. If it doesn't work, then connect the charging cable.

Step 7: Use!

Well, now the batteries of your old phones are back in business!

The case I proposed is certainly not ideal, but it will do for demonstrating the whole concept. I can even bet that you will come up with a much better solution :)

That's all, everyone brain luck!