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 have to:

• Lithium-ion battery of 18650 format,
• Case from the same drives
• 5V 1A voltage boost module.
• Charge board for the battery.
• 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 wires of 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. We solder the resistor (resistance 47 Ohm) to the USB output, on the back of the module that increases the voltage. This makes sense for charging 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 in the direction of 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 2.7V is highly undesirable.

As for the charge of the device itself. In our case, we used solar panels with total capacity 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 will charge via miniUSB in 2-3 hours. Most probably, solar panel you will use it when traveling, hiking, long distance travel.

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 appearance and also a way to get the power that meets your exact needs. By using portable battery you can charge not only phones, but also tablets, wireless headphones and other small gadgets.

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 - wireless charger, you can make it yourself. It is easy to use even when there is no car charger nearby.

Is it possible to make a charger with your own hands

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 charge 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 the coil to transmit electricity on contact with the 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 the two coils do not touch each other in any way. DIY wireless charging is a reality.

How to charge your phone

Make a portable wireless Charger almost everyone can do it with their own hands, following the instructions. The whole process consists of two parts: making the transmitter (inside) and the receiver (outside). The first of them is separate, while 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 back cover 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.

Sent:

The design of a self-made drive (PowerBank "a) of the" Vampirchik "type is described. A diagram and a description of its manufacture are given. In general, it is pleasant to read such materials, where the author approaches the matter seriously.

Prologue

The idea of ​​building this structure was prompted by a flight in an Airbus A380 aircraft, in which there is a USB connector to supply power to USB compatible devices.

But, this luxury is not found in all planes, and even more so it cannot be found in trains and buses. And I have long dreamed of reviewing the Friends series from start to finish. So why not kill two birds with one stone - watch the series and brighten up the travel time. An additional incentive for the construction of this device was the discovery of deposits of powerful lithium-ion batteries.

A portable charger (charger) should provide the following capabilities.

1. Working hours offline under rated load, at least - 10 hours. Large capacity lithium-ion batteries are perfect for this.

2. Automatic switching on and disconnecting the charger depending on the presence of the load.

3. Automatic shutdown Charger in case of critical battery discharge.

4. Possibility of forced inclusion of the charger in case of critical battery discharge, if necessary. I believe that on the road, a situation may arise when the battery of the portable charger is already discharged to a critical level, but it is necessary to recharge the phone for an emergency call. In this case, it is necessary to provide an "Emergency start" button in order to use the energy still available in the battery.

5. Possibility of charging the accumulators of the portable charger from the mains charger with the Mini USB interface. Since the charger from the phone is always taken with them on the road, you can also use it to charge the batteries of a portable power supply unit before returning.

6. Simultaneous charging of the charger and recharging mobile phone from the same mains charger. Since the mains charger from a mobile phone cannot provide sufficient current to quickly charge the battery of a portable charger, the charge can stretch for a day or more. Therefore, it should be possible to connect the phone to charge directly while charging the battery of the portable power supply unit.

Based on this technical assignment, a portable charger was built on lithium-ion batteries.

Block diagram

The portable memory device consists of the following units.

1. Converter 5> 14 Volts.
2. A comparator that turns off the charge converter when the voltage on the battery of lithium-ion batteries reaches 12.8 Volts.
3. Charge indicator - LED.
4. Converter 12.6> 5 Volts.
5. A 7.5 Volt comparator, which disconnects the charger when the battery is deeply discharged.
6. Timer that determines the operating time of the converter in case of a critical battery discharge.
7. Indicator of converter operation 12.6> 5 Volts - LED.

Switching voltage converter MC34063

It took a long time to choose a driver for a voltage converter, since there was not much to choose from. On the local radio market for a reasonable price ($ 0.4), I found only the popular MC34063 microcircuit. I immediately bought a couple to find out whether it is possible to somehow forcibly turn off the converter, since such a function is not provided for in the datasheet for this chip. It turned out that this can be done if the supply voltage is applied to pin 3, intended for connecting the frequency-setting circuit.

The picture shows a typical circuit of a step-down switching converter. A forced shutdown circuit is marked in red, which may be needed for automation.

In principle, having assembled such a circuit, it is already possible to power a phone or a player, if, for example, power will be supplied from ordinary power elements (batteries).

I will not describe in detail the operation of this microcircuit, but from the "Supplementary Materials" you can download and detailed description in Russian, and a small portable program for quickly calculating the elements of a boost or buck converter assembled on this microcircuit.

Lithium-ion battery charge and discharge control units

When using lithium-ion batteries, it is advisable to limit their discharge and charge. For this purpose, I used comparators based on penny CMOS microcircuits. These microcircuits are extremely economical, as they operate on microcurrents. At the entrance they have field-effect transistors with an insulated gate, which makes it possible to use a microcurrent Reference Voltage Source (ION). I don't know where to get such a source ( You can try to use the LM385 at 1.2V or 2.5V. Note ed.), therefore, took advantage of the fact that in the microcurrent mode, the stabilization voltage of conventional zener diodes decreases. This allows you to control the stabilization voltage within certain limits. Since this is not a documented inclusion of a zener diode, it is possible that a zener diode will have to be selected to provide a certain stabilization current.

To provide a stabilization current of, say, 10-20 μA, the ballast resistance should be in the region of 1-2 MΩ. But, when adjusting the stabilization voltage, the resistance of the ballast resistor may turn out to be either too small (several kilo-ohms) or too large (tens of mega-ohms). Then you will have to select not only the resistance of the ballast resistor, but also a copy of the zener diode.

Switching of a digital CMOS microcircuit occurs when the input signal level reaches half of the supply voltage. Therefore, if you power the reference and the microcircuit from a source whose voltage you want to measure, then a control signal can be obtained at the output of the circuit. Well, this very control signal can be applied to the third pin of the MC34063 microcircuit.

The drawing shows a diagram of a comparator on two elements of the K561LA7 microcircuit.

Resistor R1 determines the value of the reference voltage, and resistors R2 and R3 determine the hysteresis of the comparator.

Unit for switching on and identifying the charger

In order for the phone or player to start charging from the USB connector, it needs to be made clear that this is a USB connector, and not some kind of surrogate. To do this, you can apply a positive potential to the contact "-D". In any case, this is enough for Blackberry and iPod. But, my proprietary charger also applies a positive potential to the "+ D" contact, so I did the same.


Another purpose of this node is to control the switching on and off of the 12.6> 5 Volt converter when the load is connected. This function is performed by transistors VT2 and VT3.

A mechanical power switch is also provided in the design of the portable charger, but its purpose is more likely to correspond to the "battery disconnect switch" in the car.

The figure shows a diagram of a mobile power supply.

C1, C3 = 1000μF

C2, C6, C10, C11, C13 = 0.1uF

C4, C5 = 680pF

C14 = 20μF (tantalum)

IC1, IC2 - MC34063
DD1 = K176LA7

DD2 = K561LE5

R28 = 3k

R5 = 30k

VD1, VD2 = 1N5819

HL1 = Green

VD3, VD6 = KD510A

R8, R15, R23, R29 = 100k

VT1, VT2, VT3 = KT3107

L1 = 50mkH

R10, R11, R13, R26 = 1m

VT4 = KT3102
L2 = 100mkH

Are selected

R17, R19, R25 = 15k

R14 * = 2m
R1 = 180

R22 * = 510k

VD4 *, VD5 * = KS168A

IC1 is a 5> 14 Volt step-up converter, which serves to charge the built-in battery... The converter limits the input current to 0.7 Ampere.

DD1.1, DD1.2 - battery charge comparator. Interrupts the charge upon reaching 12.8 Volts on the battery.

DD1.3, DD1.4 - indication generator. Makes the LED flash while charging. The indication is made by analogy with Nikon chargers. While the charge is in progress, the LED blinks. The charge is over - the LED is on continuously.

IC2 is a 12.6> 5 volt buck converter. Limits the output current to 0.7 Ampere.

DD2.1, DD2.2 - battery discharge comparator. Interrupts the discharge of the battery when the voltage drops to 7.5 volts.

DD2.3, DD2.4 - emergency start timer of the converter. Turns on the converter for 12 minutes, even if the battery voltage drops to 7.5 volts.

Here the question may arise, why was such a low threshold voltage chosen, if some manufacturers do not recommend allowing it to drop below 3.0 or even 3.2 Volts on the bank?

I reasoned like this. Traveling doesn't happen as often as you'd like, so the battery is unlikely to have to go through many charge-discharge cycles. Meanwhile, in some sources describing the operation of lithium-ion batteries, the voltage of 2.5 Volts is just called critical.

But, you can limit the discharge limit more than high level voltage if you intend to use such a charger frequently.

Construction and details

Printed circuit boards (PCBs) are made of 1mm thick foil fiberglass. The dimensions of the PCB are selected based on the dimensions of the purchased case.

All elements of the circuit, except for the battery, are located on two printed circuit boards. Moreover, on the smaller one there is only a Mini USB connector for connecting an external charger.

The power supply units were housed in a standard Z-34 polystyrene casing. This is the most expensive part of the structure, for which I had to shell out $ 2.5.

The power switch, pos. 2, and the forced-on button, pos. 3, are hidden flush with the outer surface of the case, in order to avoid accidental pressing.

The Mini USB connector is routed to the back of the case, and the USB connector, pos. 4 together with indicators pos. 5 and 6 to the front.

The printed circuit boards are sized to fit the batteries into the portable power supply case. Between the batteries and other structural elements, a 0.5 mm thick electrical cardboard gasket bent in the form of a box is inserted.

And this is a portable power supply unit assembled.

Customization

Setting up a portable charger was reduced to the selection of instances of zener diodes and ballast resistor resistances for each of the two comparators.

How to fit resistors with high accuracy is described.

Insofar as portable devices are a necessity in modern day to day life and may be subject to overuse, improper charging or normal wear and tear.

This article has an amazing idea on how to make your own simple portable charger for phone. It will be easy and inexpensive to assemble such a device; this will require a soldering iron, flux, solder, a 9-volt Krone battery, a battery connector, a USB connector, an L7805 voltage regulator and, of course, a small box from Tic Tac, in which all the electronic filling will be placed. If you do not dare to make a homemade product, then take a look at this Chinese store.

The voltage regulator has three wires. First, the entrance. The second is the mass, the third is the exit. The numbers 05 in the marking of this device mean that the output on it will be 5 volts.

First you need the output of the stabilizer, and this is the right foot, to solder to the plus of the USB connector. After that, we need to solder the middle lead to the negative terminal. Finally, we solder the wire with a plus from the connector of the crown to the first leg of the stabilizer. This is his entrance. The second wire from the connector of the crown, with a minus, is connected to the second leg of the stabilizer, that is, to the minus and to the mass.

Now all this can be placed in a tick-tock box. Let's test the portable charger. Let's do everything required connections... And we see that the charge indicator shows that the phone has started to be powered by this autonomous device. Of course, such a charge will not last long, so for long-term operation you need to take a battery crown.

You might be interested in one that can be used as a device with the function that was described in our article.

DIY USB Charger WITH MINTY BOOST

WE WERE LUCKY, that we live in a time when portable electronic devices allow us to do things that a spaceship full of science fiction writers could not even dream of decades ago. The only downside to the iPhone, Nintendo DS, Kindle and others is their constant need to recharge. And it seems that no matter how careful you are to get above it before your trip, you can always not work at the most inconvenient moment. Sure, there are DC cables for the car, plugs on commuter trains, and even USB charging plugs at airports, but there are millions of other places where you'll find you don't have fast charging options.

Admittedly, it's hardly even first world problem but this is definitely a challenge for GeekDad who loves to solve problems.

Then what's the solution? Well, we could buy a bulk solution like Philips USB Power Station but it is a little expensive and seems like a too easy answer. So what would McGeever do in this situation? Of course he builtMinty Boost charger !

Minty Boost Kit Contains printed circuit board and all the parts needed to assemble a portable USB charger that runs on regular AA batteries. The kit requires soldering to be assembled, which can be a problem for some. It is, however, a fairly simple project, andinstructions at AdaFruitfantastic. If you're looking for your first soldering project, this is a great choice.

I put my Minty Boost together in about an hour and I didn't even manage to burn myself out for a change. Here are some examples of actions:

Once the basic assembly was complete, it was easy to plug in a pair of AA batteries and test everything. When I first checked the output with a multimeter, output voltage was a little low at 4.8V. This was due to the nearly dead AA batteries I was using. After I replaced them with new batteries, the output voltage was above 5.0V as expected.

I have been using communicators for a long time, a very convenient thing all in one - a notebook, calculator, flashlight, video and photo camera, internet, video and MP3 player, navigator, safe (for information), radio, game console, and a lot more. Super gadget - what else can you dream of? And I'll tell you what, about a small nuclear reactor instead of a battery! But on this moment we break off, and rejoice in the li-ion battery which, with a good load of the device, lasts for 3 hours. There is a way out: we remove the brightness of the phone to a minimum, cut down the Internet, delete the live wallpaper, switch to the “on the plane” mode, turn it on only to make a call, and then the phone (as stated by the manufacturer) lasts for two days. In general, this is not an option, and I was seriously interested in alternative power sources, it will be about an additional battery for your gadget or "Vampire"

Let's start with the most basic, these are batteries, I put two cans of li-ion purchased in radio goods in Vladivostok when I was there on vacation, you can buy, in principle, any and in any quantities (within reasonable limits) suitable in size, the most important thing is more greed , oh, capacity. We increase the capacity by parallelizing the cans. Only identical batteries can be paralleled, ALWAYS balancing them with each other - we connect the minuses (as a rule, they are the body of the can, and we connect the pluses with a resistor with a resistance of 30 ohms.
We measure the voltage at the terminals of the resistor with a voltmeter. We wait, it happens a day, it happens right away the same values... As soon as it becomes less than a hundred millivolts, they can be connected directly, without a resistor. We solder them together and solder the ends to the controller (can be obtained from any old battery cell phone) Here we have a high-capacity battery.
WORKING WITH NAKED BANKS WITHOUT A CONTROLLER, WE DO NOT CONFUSE THE POLARITY AND DO NOT MAKE A SHORT CIRCUIT IN NO EVENT!

We put it aside and scratch the turnip than to charge it, now, of course, it's a matter of charging from a cell phone. They are everywhere and always, and most of them have a USB outlet.

You can directly solder the wires to the battery and the usb dad and plug them into the charger, they usually go 5V 1A. But so boring and uninteresting, I decided to make a charge indicator. They turned on the red LED in the charging, the battery was charged, the green turned on, they were disconnected from the charging, both went out.

Transistors marked t06 - p-n-p PMBS3906, 100mA 40V, complementary to PMBS3904. Dropped out of the old motherboard.

Resistors R1 and R2 marked 471 - 470 Ohm Obtained from old controllers for a cell battery

Resistor R3 can be set with a value of 1.5 Ohm, but I did not find such a one, put two in parallel, 1 Ohm each, and that turned out to be 0.5 Ohm. I put two because I was afraid that they would get very hot at a charge current of about 0.5A Marking 1R00 found on the diagram hard disk from the laptop.

Diode marked SS14 Description: Diode, Schottky, 1 A, 40 V I was lying around, I don’t know where it came from, but if there is iron with SMD parts, you will find something similar on it without any problems.

I bought the most common SMD 3V red and green LEDs, but it is quite and in excess you can solder from cell phone boards.

I assembled a circuit from what was more or less similar to resistors R1 and R2 can be set to 330 Ohm

Many thanks I would like to convey to the Electronics Forum cxem.net... The theme of the development of the indicator, by joint efforts and especially by a Kival participant. Maybe someone will come in handy for general development.

The assembly of the parts was carried out on a piece of copper PCB, cut from the board.

Then we mount this little wonderful device on usb "dad" I plucked out of the old data cable

We plug into the charger and check the performance

Without load, both LEDs are lit, under load, the green one goes out.
In short, the principle is very simple - when the battery is charged, the current flows through the circuit and does not allow the green LED to glow, as soon as the controller fulfills that the battery is charged and does not fit into it anymore, the circuit opens, the current stops flowing and turns green as soon as you pull out the diode from charging D3 does not allow the current from the battery to go to the indicator and both go out.

Well, it seems we have decided on the indicator and charging, now we need to figure out how we will feed the phone from the battery, because we have the output from 3.7v to 4.2v, and for charging the cell it is tenderly not less than 5V, and even more for Nokia. Here we need a DC-DC step-up converter Here I pass, I will not draw diagrams and grovel about this, because the Internet is teeming with this material, and I do not have a radio parts store in my city and therefore I did not bother with soldering this element, but stupidly (or cleverly) ordered from the internet . You can also buy a Chinese charger from one battery and pick it out from there, but I personally doubt its reliability, but we will charge it, not for halam bali, but expensive communicators.

It would seem that everything is there and it remains only to connect everything with wires, but during the operation of the device there were some inconveniences, here my device lies like a piece of plastic and it is not clear whether there is a charge in it or is it empty? And lithium-ion batteries do not like being discharged. I wanted a voltmeter, a small compact voltmeter, since the device was assembled and the place for it was not initially laid. the search for schemes, recipes and ready-made units began. And by chance - I go to a mobile accessories store and see the miracle of the Chinese flight of engineering.


Yes, yes, a frog with an LCD screen worth 150 rubles.
I quickly picked it up 🙂 as it turned out, the voltmeter circuit was executed separately, from pulse transformer and is very easy to drink. The most important thing is to remember how the screen was soldered and where to solder the power wires (by the way, as it turned out, the polarity does not matter) Since my memory has long been relaxed digital technologies- decided (in order not to forget you need to take a picture)


After all the manipulations, we get a voltmeter for 4 divisions With such characteristics 4 bars 4.14V / 3 bars 4.04v / 2 bars 3.94V / 1 bar 3.84V / then an empty battery remains until the battery controller cuts off the power, this is about 3 , 4 - 3.6V
Since the voltmeter also consumes a certain amount of electricity dear to us, we connect it through the button. Pressed looked released!

Next, we are looking for a suitable box where we can put all our acquired by back-breaking labor, welded together with sweat and blood. In an unequal battle, I recaptured the box with the shadows from my wife (the shadows and the mirror were returned) and put everything there.

We solder according to the scheme

I placed the USB connectors on a strip of tin in order to increase the area when gluing. We glue the battery on double-sided tape, the button for super glue, USB connectors are soldered (as mentioned above) are soldered to the tin, which in turn is glued to the super glue, we cut out a rectangular hole under the LCD screen, we install and fit carefully - the glass is very fragile. We sit on hot melt glue.

Well, that's all! We refine it to your taste and use the device!