And so, the first converter circuit is made on the UC3845 timer, the microcircuit plays the role of a master oscillator. A powerful field-effect transistor amplifies the voltage and supplies it to the transmitting coil, thus forming in the winding alternating current high frequency, which creates an electromagnetic field around the circuit. Due to this, an alternating voltage is formed in the second coil, this voltage must first be rectified, then the interference should be smoothed out with a capacitor and supplemented with a zener diode to stabilize the voltage.
We select the zener diode based on the voltage with which you can charge the phone, for most phones the voltage rating is 5.5 volts.
Let's move on to the details of the circuit. The diode in the circuit must be ultra-fast, other types of diodes will not work! We select a 820 ohm resistor with a power of at least 2 watts, it will heat up and low-power diodes will simply burn out. The field-effect transistor can be replaced with a similar one, the power of this converter is quite large - up to 70 watts, and therefore the transistor must be strengthened on a heat sink. The inductor can be excluded from the circuit, it is wound on a ferrite ring from an old power supply and contains 20 turns of wire, with a diameter of 0.8 - 1mm. It serves to smooth network interference. The transistor can be replaced with an IRFZ44, although it will work a little worse.
The printed circuit board is shown below.
Let's talk about contours. The transmitter circuit contains 20 turns, the inner diameter of the circuit is 10 cm, the circuit is wound with a wire with a diameter of 0.5 to 1.5 mm, when using a thick wire (diameter from 1 mm), the power of the transmitter field will increase, this will allow charging a mobile phone at a distance of up to 30 - 40 cm from the receiver. To increase the range, you can use large coils with a diameter of up to 1 meter. The receiver circuit contains 40 turns of wire with a diameter of 0.4 - 0.7 mm. See receiver diagram below.
The second circuit (receiver circuit) can be used from the old hard drive(disassemble the device and see where it is), the coil provides the desired voltage and has a compact size, it can be adapted to the back of a mobile phone, it is advisable to use diodes for rectification in smd version, to save space, a capacitor with a voltage of 16 volts, a capacitance of 220 up to 470 microfarads. We connect the power through the appropriate plug to the mobile phone, then turn on the transmitter (the transmitter is powered by a stabilized power supply of 10-12 volts, the current is from 3 amperes), then you just need to put the mobile phone at 10 - 50 cm from the transmitting coil.
The second circuit is assembled on reverse conduction transistors, the frequency is set by a multivibrator, then the signal is fed to a transistor voltage amplifier, as a result of which an electric current of high frequency is formed in the circuit. Transistors multivibrators can be used KT315 or imported analogues C9014, C9018 or others. The remaining transistors of the KT819 type, in extreme cases, can be replaced with KT805, the last transistors must be strengthened on the heat sink. As noticed this scheme powered by two different voltages, to power the multivibrator, you can use any DC source with a voltage of 4 to 6 volts (you can use lithium - ion battery from a mobile phone), to power the transistor amplification stage, you need a voltage of 10 to 14 volts with a current of at least 1.5 A.
This scheme is no worse than the first, so you choose which one to collect! The resistors in the second circuit are all 0.5 watts. To create this article, a previously made one was donated ... but I think it was worth it, although many will probably not understand me, but this is something new, because such topics have not been previously considered on the Internet, then alternative solution, and your mobile phone will charge faster than usual (depending on the distance of the coils). The maximum current transfer distance at the indicated ratings is 50 cm, then the current strength will drop sharply.
Imagine: you are holding a cell phone in your hands and talking with a friend, and at that moment your phone is charging, and most importantly, the charger wires do not stick out of it. I propose two ways to implement this idea, or rather one way - the method of current induction without wires, and there are two design options for such a wireless charger.
The first option is the simplest, made exclusively according to a transistor circuit, the frequency is set using a multivibrator, then the signal is amplified by transistor cascades.
Two coils (rings) that do not have a core, thus, by the law of induction, due to free oscillations in the second circuit, we obtain an alternating voltage, which is rectified using a diode bridge, then stabilized using a capacitor, and for final stabilization, you need to set a zener diode to 6 volts. So, as a result, we get a master device (transmitter) that is powered by a voltage of 10-12 volts, the device creates a magnetic field due to the coil, and the receiver in which an electrical voltage is generated. The transmitter and receiver have identical coils, although they can be resized for experimentation.
The second version of the wireless charger circuit is made on the UC3845 chip. The microcircuit plays the role of a master oscillator, and a powerful field-effect transistor amplifies the voltage. The choice of scheme is yours, I can only say that both schemes are good and have been tested more than once. You should not change the ratings of the parts, they are already carefully selected, experiments can only be done on coils, but we offer an option with which you can charge a mobile phone at a distance of half a meter from the transmitting circuit. If you decide to assemble the first option (a transistor circuit), then all transistors (except for multivibrator transistors) must be installed on heat sinks, a heat sink is also needed for a field-effect transistor in the second circuit. The microcircuit does not need a heat sink. The 820 ohm resistor in the second circuit must be selected with a power of 2 watts.
The second circuit (receiver circuit) was used from an old hard drive (disassemble the device and see where it is), the coil is what you need, provides the desired voltage and has a compact size, you can adapt it to the back of a mobile phone, it is advisable to use rectifier diodes in smd execution, to save space, a capacitor with a voltage of 16 volts, a capacity of 220 to 470 microfarads. We connect the power through the appropriate plug to the mobile phone, then turn on the transmitter (the transmitter is powered by a stabilized power supply of 10-12 volts, the current is from 3 amperes), then you just need to put the mobile phone at 10 - 50 cm from the transmitting coil.
Now it's time to move from theory to practical application of this design. We will consider each of these methods separately. Let's start with the transistor circuit. For this circuit, you need to have two power supplies, the first 3.7-5 volts (to power the low-voltage circuit) and 12 volts 4-10 amps to power the transistor stage. Transistors in the multivibrator can be used type kt315 or its domestic and imported counterparts. The remaining transistors of the kt819 type or analogues, they must be installed on the heat sink. The transmitter coil has 20 turns, wound with a wire with a diameter of 0.5-1 mm, the coil diameter is from 5 cm to 1 meter (the diameter is selected based on needs).
The receiver circuit consists of 30 turns of wire with a diameter of 0.5-0.8 millimeters, its diameter is not more than 10 centimeters. The circuit is capable of charging your mobile phone at a distance of up to half a meter! You can rectify the charging current with a diode bridge or using just one diode, a capacitor with a capacity of 220 - 470 microfarads (it makes no sense anymore).
The second circuit is more complex, but it has greater stability, the circuit is powered by a voltage of 10 - 14 volts, while a constant voltage source of 3 - 10 amperes is needed. Field-effect transistor, it will heat up and a larger heat sink is needed! An 820 ohm resistor, as already mentioned in the first article, is needed with a power of 2 watts, ceramic capacitors marked 105 have a capacity of 1 microfarad. The number of turns of the coils and the diameter of the wire are the same as in the first circuit, rectification and stabilization of the receiver current also occurs in the same way as in the first design.
During such charging, the distance between the transmitting and receiving coils plays an important role, the closer they are to each other, the greater the voltage in the second circuit, and in order not to burn the phone, the transmitter must be supplemented with a voltage regulator of 6 - 7 volts, such stabilizers can be obtained by dismantling the ordinary Charger for mobile phone. This wireless charger can charge your mobile phone in very a short time, since the current in the second circuit can reach a value of more than one ampere. In this way, you can charge a laptop or other devices that are charged or powered by a low-voltage DC source. Think carefully where you could use such a wonderful device that allows you to transfer voltage without wires! The areas of application of the memory are very large, we leave the choice to you!
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Since no one has yet invented an eternal source of energy, you have to regularly recharge the batteries. cell phones and various digital gadgets from the mains. It is not always possible to do this in the usual way through a wire and an outlet. Some advanced companies have already begun to release models that can be charged just by being on the site. wireless device. Following their example, the "home-made" do not stand on the sidelines, but try to improve even some push-button phones.
To understand for the phone, you need to remember Nikola Tesla and his way of transmitting energy at a distance. With the help of a device that works according to the method, more than 100 years ago, he managed to provide an entire state with electric current.
How is it being used now? There is a built-in coil, which is the creator and transmitter of the magnetic field to the antenna of the device. The receiving circuit is a coil laid in a flat spiral, placed directly under the phone cover. Electromagnetic radiation occurs only after the receiver is placed in the field of the transmitter. Then, through the capacitors and the rectifier, the energy acts on the battery.
Can there be any negative aspects of such a wonderful invention? It turns out there are several:
There is no information about other cons yet.
The input for connecting the charging cable on the old phone does not work? Now this is an easy task! A little more than a meter of thin is taken copper wire and is wound into a flat coil of 15 turns. In order for the spiral to retain its shape, it is fixed with superglue or double-sided tape, leaving a couple of centimeters of wire for soldering the contacts. With the phone charging socket, one end of the coil is connected through a pulsed diode, the other through a capacitor. Do-it-yourself wireless charging is not a joke, but the use of the laws of physics.
To make a transmission circuit, 1.5 cm turns are laid around a circle with a diameter of 10 cm. The winding is fastened with electrical tape or tape, leaving both ends of the wire free. From thinner copper for the transmitter, 30 turns are wound in one direction. The circuit is closed by a field effect transistor and a capacitor. Wireless charging (with your own hands) is ready: if you put the phone with the receiver under the cover inside the transmitting ring with the screen up, the battery will begin to receive energy.
Laptops and cameras, cameras and tablets - all these devices require constant power. Moreover, it is very inconvenient to store at home or carry with you a whole set of several different wires. To get rid of this inconvenience, some time ago several of the world's leading manufacturers mobile means communications agreed to maintain a single standard in the use of chargers.
Gadgets that support this feature are marked with the Qi logo. It is planned to equip cafes, libraries and other public places with such technical equipment. IKEA designs furniture for work panel which has built-in wireless charging. With your own hands, you will only need to put your phone or laptop in the designated place (for the night or lunch time), as the energy begins to flow.
Wireless charging for Samsung is by far the most unusual, as it is a functional computer monitor that supports standard OS. The installation of this device allows not only to free the work surface from unnecessary wires for mobile phones, feeding them from a distance: when the gadget is placed on its platform, charging starts automatically, and a green LED light lights up on a monitor that supports the universal Qi standard.
Not so long ago, the inventors of Nikola Labs demonstrated one of the covers. This one is capable of accumulating wasteful radio frequency radiation. wifi signals converting it into energy. Thanks to this miracle case work time smartphone is extended by almost a third.
Smartphone manufacturers compete with each other, equipping each new model some unique feature. So phones with the function became available to users. Convenient, fast, it promises maximum comfort when working with the gadget. But, as a rule, it does not come with a smartphone. The cost of the cheapest model starts from 700 rubles, more or less normal will cost 2.5 thousand rubles. And of course, the user has a logical question: how to make wireless charging with your own hands? It turns out that if you wish and if you have some details, it is quite simple to do this, but first you need to familiarize yourself with all the accompanying nuances.
The wireless charger allows the phone without connecting the latter to the wires. The mobile phone is placed on a special stand, where the whole process takes place.
The principle of operation is to transfer the magnetic field from the transmitter to the receiver. The second in this case begins to generate voltage, which charges the battery.
The presence of a built-in receiver can be seen in the characteristics, if the manufacturer indicated support for the Qi standard, then everything is in order.
ATTENTION. The lack of a built-in receiver in the gadget is not a reason to abandon the idea. In this case, the owner of the smartphone just needs to make a little more effort and make the receiver himself.
There are several options for performing work, the essence of which ultimately boils down to one. If you place all the elements on a clean board, attach them with a soldering iron and equip the design with a choke, you can get a high-quality device. It will be able to deliver voltage up to two amperes, working reliably and smoothly. However, if you have a minimum of materials at hand, you should use a simpler scheme. To choose the most suitable option, it is worth considering both.
Before you make a reliable and high-quality wireless charger with your own hands, you need to prepare:
First of all, a circuit is made from a long wire. To do this, the wire is folded in half, with the help of fingers or a contour with a diameter of 5–10 centimeters, 5 turns are wound. Around the entire circumference, the contour is firmly fastened with adhesive tape or glue.
Next, you need to cut the loop resulting from folding the wire in half, you get 4 free ends. They are cleaned, the beginning of the first winding is connected to the end of the second, the end of the first winding to the beginning of the second. A multimeter will help determine which end to connect to. The "active" ends are soldered together, forming a midpoint. It is she who will go to the plus power through the throttle. Resistors will be connected to the free ends in the future.
It is assembled for the phone with your own hands in the following sequence: two transistors are soldered, then diodes to them, to diodes, in turn, resistors. The ends of the latter are distributed between the board and the diodes. The contour is soldered last, tinning of both windings is preliminarily performed.
A do-it-yourself transmitter for a smartphone assembled in this way creates a high-frequency field on the primary circuit, which is smoothed out by a capacitor on the secondary and stabilizes to approximately 5 volts.
The second option will tell you how to make wireless charging for your phone more in a simple way from a minimum of materials. You will need:
The wire is wound in forty turns on the frame. It must be prepared in advance, based on the optimal diameter of 7-10 centimeters. After the twentieth turn, a layer is made. A resistor is connected to it and the end of the coil, on this the device is considered ready.
ADVICE. It is worth considering the conductivity of the resistor, if it is direct, the polarity must change during assembly.
The transmitter should be placed in the case, a box from under the disks is perfect for its role.
If the smartphone is not equipped with a built-in receiver, then it will take time to manufacture it. You can install your receiver not only on a smartphone, but also on a regular push-button one, since it is connected to the battery.
Do-it-yourself wireless charging for a smartphone in this case will require a wire with a diameter of 0.3–0.4 mm. Double-sided tape and superglue will also come in handy. For convenience, work on creating a contour can be performed on a plastic surface.
The receiver consists of 25 turns tightly pressed against each other. So that in the future the structure does not break, it is recommended to mount the turns on double-sided tape and, as the area increases, fill them with superglue.
In addition to the wire, the receiver includes a silicon diode, the marking of which does not make much difference. The coils of the second part are carefully separated from the surface and connected to the device through a diode.
In addition to how to make wireless charging, you should also think about how to connect it. The receiver can be connected to either a battery or a charger connector. The second option, as practice shows, is more preferable.
It remains only to fix the made receiver on the cover of the smartphone and you can start testing.
IMPORTANT. To check the performance of a wireless memory, you should take old phone, the loss of which due to errors in the assembly will not cause damage to the owner. It is also not recommended to charge a phone that is under the manufacturer's warranty in this way.
Before you learn how to make your own wireless charging, you should know the following:
Mobile devices have long become an integral part of the life of a modern person. But for their work, you must constantly use the power supply to replenish the battery life. The cord often becomes a hindrance when using the gadget in the process of recharging. To effectively solve this problem, it is enough to learn how to make wireless charging with your own hands?
Wireless charging is not an innovation. They are created on the basis of technology developed many years ago by engineer Nikola Tesla. The latter found a way to transfer energy at a distance. This was achieved thanks to magnetic induction. The discoverer of the technology was thus able to provide electricity to an entire state.
In gadgets, the technique is applied as follows. The coil built into the charger plays the role of the creator and conductor of the magnetic field, which is directed to the antenna of the device. A flat spiral coil, located under the cover of a mobile phone, acts as a receiving circuit. The emission of electromagnetic pulses is activated only after the receiver enters the transmitter's coverage area. Through capacitors and a rectifier, the battery of the gadget is affected.
Experts have found that such a convenient device at first glance has some significant drawbacks. These include:
To improve the mobile phone, you need to perform a series simple actions. After updating the gadget, problems such as failure of the charging socket, tangled wires, and so on, will become insignificant.
To implement wireless charging, you will need parameters of thin-section copper wire. The conductor must be wound into a coil. The optimal number of turns is 15 pcs. It is desirable to fix the spiral with glue or double-sided tape in order to maintain its shape. At the same time, a few centimeters of wire are left for soldering the contacts. To connect to the charger socket, a pulsed diode and a capacitor are used, attached to different ends.
In order to create a wireless charging transmitting circuit, coils of 1.5 cm in size are formed. The diameter of the coil after twisting should be 10 cm. Both ends should be free. The rest of the structure is fastened with electrical tape or adhesive tape.
Next, 30 turns of a thinner copper conductor are wound for the transmitter. A transistor and a capacitor are used to close the circuit. By placing the device, equipped under the cover of the receiver, in the zone of the transmitting ring with the display up, you can achieve wireless charging of the phone.
Such universal device will be indispensable in any home. Today, almost every user has a whole arsenal of mobile equipment: laptops, tablets, e-books, cameras. It is extremely inconvenient and impractical to use personal charging for each of them.
Leading manufacturers of equipment helped to solve this problem. Some time ago, they agreed to complete the devices with chargers that have a single standard. Equipment that supports this function is marked with the Qi symbol. It is likely that such technologies will soon appear in public institutions - restaurants, cafes, libraries, etc. It is worth noting that the largest "apple" brand was not included in the association of manufacturers. Later, the developers of this company released their own iQi Wireless Charger.
If you are interested in assembling a homemade charger, you should watch a video with a master class. Here, the developers cut the USB cable into three parts, removing the middle part. The remaining fragments were used to attach the induction coil. To strengthen the field of influence, a magnet was placed on the power supply. This experiment showed that the coverage area here is 15 m.
We are all tired of a bunch of extension cords and wires that get tangled with each other, get dusty and get lost.
Extension cords frayed wires and they stop charging. Or the problem may be in the socket of the smartphone. One way or another, but wireless charging can make life much easier.
True, it is still impossible to call it completely wireless. The device itself will still have to be connected to a source of electricity. But you can just put the phone on the charger and go about your business with a clear conscience.
The cost of such devices may vary. There are more expensive ones, and there are cheaper charging cables for phones that are familiar to us. However, some enthusiasts are trying to make wireless charging their own. There may be several reasons for this. Perhaps someone prefers to get by with minimal means. Or maybe the passion for creating something with your own hands plays a role here. We wrote about this above.
How to make a reliable homemade probe for an oscilloscope or multimeter - photo tutorial.
