DIY car charger for your phone. Homemade USB power supply in the car

The MC34063 is a popular microcircuit for designing small circuits of transformerless voltage converters. It is universal, since it is possible to make step-up, step-down and inverting DC-DC voltage converters on its basis. The range of input and output voltages allows you to easily assemble a number of voltage converters on the basis of this microcircuit with minimal costs, which are indispensable in everyday life.

Of course, all these designs can be bought in China, ready-made, but we will not talk about this today, you can buy everything in China, but with your own hands it is more interesting.

We will consider the design of a voltage step-down converter, the input of which can be supplied with a voltage from 5/6 to 40 volts, while the output voltage will always be kept stable, at the level of 5 volts. 5 Volts charge all mobile phones, tablets, some players and turntables.

The microcircuit is very popular among radio amateurs precisely for the reason that it costs a penny and contains a minimum strapping.

Choke, rectifier diode (Schottky) and several passive components. The output voltage may be different, there are a bunch of programs and formulas for calculating inverters on this microcircuit. The output voltage depends on the ratio of resistors R3 / R2.

The diode, in principle, is also not critical and you can take ordinary pulsed ones, you can from the FR / UF / HER / SF line, etc.
A diode is needed with a current above 1.5 Amperes, preferably 3, since the output current from the microcircuit can reach up to 1.5 Amperes. The choke itself is wound on a ferrite dumbbell, a ring is also possible, the winding is wound with a wire of 0.6-0.8 mm and consists of 15-20 turns. You can take a ready-made choke from some computer power supplies.

Capacitor C1 is responsible for the operating frequency of the generator built into the microcircuit; it is advised to run the microcircuit at frequencies of 40-60 kHz.

By the way, on the specified microcircuit, single-ended voltage transformer converters are also implemented, to obtain a wider output voltage range and provide galvanic isolation. In this case, the power can also be raised, because in this case the output of the microcircuit is reinforced with a powerful transistor.

Scheme charger shown in Figure 2, it is a DC-DC converter that provides a stable voltage of + 5V at a current of up to 0.5A, and an input voltage within 7..18V. Looking at the diagram, the question may arise - why such difficulties when, it would seem, you can get by with one "roll"? The question is fair. Indeed, a similar charger can be made, for example, according to the diagram in Figure 1.

Figure: 1

And this scheme will work. But, pay attention to the fact that KR142EN5A is a regular linear stabilizer, and with an input voltage of 12V and a load current of 0.5A, the power that will be dissipated by the regulating transistor of the KR142 EN5A microcircuit can be more than 6W. The microcircuit will heat up; a sufficiently voluminous and heavy radiator is required. Not to mention the low efficiency of such a circuit.

Figure: 2

The circuit shown in Figure 2 works like pulse source, and dissipates very little power during normal operation. There is absolutely nothing here that requires heat removal. Besides the fact that it has a very high efficiency, this circuit allows the adapter to be assembled in a very light and compact design.
Of course, there is also a minus - the circuit is much more complicated, contains many parts, the total cost of which is significantly higher than the price of KR142EN5A and a pair of capacitors.
The "charging" is connected to the car cigarette lighter. The VD1 diode, just in case, protects the circuit from incorrect polarity of the input voltage (suddenly the cigarette lighter was changed and connected incorrectly). Zener diode VD2 - protection against short high voltage pulses, which may be in the network of a not very new car.
On the A1 microcircuit, the main components of the converter are assembled - a pulse generator, a regulator of their width and a measuring comparator that compares the output voltage with a reference voltage generated by the internal stabilizer of the microcircuit. Comparator input, - pin 5. It is supplied with voltage from the output of the circuit through a divider on resistors R4-R6. The division factor depends on the position of the slider of the tuned resistor R5. With this resistor, when setting up the converter, the required output voltage is set (in this case, it is 5V).
Details. Diode VD1 - any rectifier silicon diode with a permissible forward current of at least 0.7A. VD2 is a medium-power zener diode with a stabilization voltage of 20-30V. VD3 is a Schottky barrier diode with a recoverable forward current of at least 2A. VD4 is a medium power zener diode with a stabilization voltage of 5.0-5.6V. HL1 - any indicator LED.
Please note that all diodes and zener diodes, the types of which are indicated in the diagram, have a CATHODE marked on the body with a belt
Capacitors C1 and C4 are any electrolytic small-sized, for example, K50-35 or JAMICON, with an allowable voltage C1 - not less than 20V, C4 - not less than 6.3V.
Resistors are ordinary. Resistors R1, R2, R3 can be replaced with one 1W resistor with a resistance of 0.3 Ot. The resistor must be non-conductive.
The L1 coil is wound on a ferrite ring with a diameter of 16 mm; for winding, a PEV wire - 0.47 is used. The number of turns is 80. The winding is evenly distributed over the entire circumference of the ring.
If all the parts are in good order and there are no installation errors, adjustment is only the adjustment of the output voltage with the resistor R5.
The same circuit can be used to charge the battery of the MP-3 player, for example, by making an output cable with a USB connector, you can charge the battery of the MP-3 player of an iPOD or other similar. In principle, on the charger case, you can install some kind of connector as X2, for example, USB (+ 5V to pin 1, -5V to pin 4), and make several replaceable cables (for a phone, radio station, MP-3 player and etc.). If you need a different voltage, respectively, readjust the divider R4-R5-R6 and replace the Zener diode VD4.

The topic of this review is car-powered mobile phone chargers. It's no secret that car battery has a voltage of 12 volts, and of course it is not possible to directly charge a mobile phone from such a voltage. To charge the phone, you need to have a reduced voltage of 5-6 volts. It is for this purpose that special chargers have recently been produced, which are designed to charge a mobile phone from a 12 volt source.

There are many designs and circuits of such chargers. Let's dwell on some of them and analyze them in more detail.

Car charger for mobile phone from cigarette lighter.

This diagram is drawn from the printed circuit board of the finished charger. The label contains the following information: "Compatible With SAM 411/611/2000/3500/8500 Made In China" Output voltage 5.4 - 5.7 volts, output current up to 700 milliamps; as it turned out later, it is intended for charging a Samsung CDMA mobile phone. I am sure that this scheme will be suitable for other devices of other standards as well.
Consider the diagram of a charger from the vehicle's on-board network.

Brief characteristics of parts:

2SA733 - 60 V; 0.1 A; 0.25 W; 180 MHz (original analogue of KT3107)
SS8550 - 40 V; 1.5 A; 1 W; 100 MHz (rep. Analogue of KT6115 and KT6127)
2SC945 - 60 V; 0.1A; 0.2 watts; 250 MHz (rep. Analogue of KT3102)
1N5819 - 40 V; 1 A; Uf 1N4148 - 100 V; 0.2 A; L - choke, wound on a ferrite core, 10 turns of PEV-2, Ø 0.3 mm

When repaired, the SS8550 was defective in this unit. Yandex offered KT6115 and KT6127 as an analogue; I didn't have those. From what was available, I put KT626A. Additional holes in the PCB layout made it possible to install this transistor without problems, despite the fact that the KT626A has a different pinout.
The characteristic of KT626A is as follows - 250 V; 10 watts; 75 MHz. Not exactly what you need, but it still works. With an input voltage of 12 V (from a glue sealed battery), the measured output voltage without load (without a telephone) was 4.08 V.

It should be noted that an electrolytic capacitor is not soldered on the board, which goes with a plus to the common point of resistances of 2 kΩ and 1.6 kΩ, and minus, respectively, to a minus. Also at the exit before the point "+ to phone." a diode must be installed, but it is not. China is China. In a word - Made in china.

Car "charger" for a cell phone.

The charger circuit is shown in Figure 2, it is a DC-DC converter that provides a stable voltage of + 5V at a current of up to 0.5A, and an input voltage within 7..18V. Looking at the diagram, the question may arise - why such difficulties, when, it would seem, you can get by with one "roll"? The question is fair. Indeed, a similar charger can be made, for example, according to the diagram in Figure 1.
And this scheme will work. But, pay attention to the fact that KR142EN5A is a regular linear stabilizer, and with an input voltage of 12V and a load current of 0.5A, the power that will be dissipated by the regulating transistor of the KR142 EN5A microcircuit can be more than 6W. The microcircuit will heat up; a sufficiently voluminous and heavy radiator is required. Not to mention the low efficiency of such a circuit.

The circuit shown in Figure 2 operates as a switching source and dissipates very little power during normal operation. There is absolutely nothing here that requires heat removal. Besides the fact that it has a very high efficiency, this circuit allows the adapter to be assembled in a very light and compact design.

Of course, there is also a minus - the circuit is much more complicated, contains many parts, the total cost of which is significantly higher than the price of KR142EN5A and a pair of capacitors.
The "charging" is connected to the car cigarette lighter. The VD1 diode, just in case, protects the circuit from incorrect polarity of the input voltage (suddenly the cigarette lighter was changed and connected incorrectly).
Zener diode VD2 - protection against short high voltage pulses, which may be in the network of a not very new car.

The A1 microcircuit contains the main components of the converter - a pulse generator, a pulse width regulator and a measuring comparator that compares the output voltage with a reference voltage generated by the internal stabilizer of the microcircuit. Comparator input. - conclusion 5.
It is supplied with voltage from the output of the circuit through a divider on resistors R4 - R6. The division factor depends on the position of the slider of the tuned resistor R5. With this resistor, when setting up the converter, the required output voltage is set (in this case, it is 5V).

Details.

Diode VD1 - any rectifier silicon diode with a permissible forward current of at least 0.7A. VD2 is a medium-power zener diode with a stabilization voltage of 20-30V. VD3 is a Schottky barrier diode with a recoverable forward current of at least 2A. VD4 is a medium power zener diode with a stabilization voltage of 5.0-5.6V. HL1 - any indicator LED.
Please note that all diodes and zener diodes, the types of which are indicated in the diagram, have a CATHODE marked on the body with a belt
Capacitors C1 and C4 are any electrolytic small-sized, for example, K50-35 or JAMICON, with an allowable voltage C1 - not less than 20V, C4 - not less than 6.3V.

Resistors are ordinary. Resistors R1, R2, R3 can be replaced with one 1W resistor with a resistance of 0.3 O. The resistor must be non-wire.

The L1 coil is wound on a ferrite ring with a diameter of 16 mm, for winding, a PEV wire - 0.47 is used. The number of turns is 80. The winding is evenly distributed over the entire circumference of the ring.

All parts are placed on a printed circuit board, the installation and wiring of which is shown in Figure 3.
The board is placed in a plastic case with dimensions of approximately 120x30x20 mm. From the sides of the ends, two cables go out, one of which ends with a standard connector for connecting a portable lamp to a car cigarette lighter, and the second with a plug like that of your mobile phone charger.

If all the parts are in good order and there are no installation errors, adjustment is only the adjustment of the output voltage with the resistor R5.

The same scheme can be used to charge the battery of the MP-3 player, for example, by making an output cable with a USB connector, you can charge the battery of the MP-3 player of the iPOD or other similar.In principle, you can install some kind of connector on the charger case as X2 ... for example, USB (+ 5V to pin 1, -5V to pin 4), and make some replaceable cables (for phone, radio, MP-3 player, etc.). If you need a different voltage, respectively, readjust the divider R4-R5-R6 and replace the Zener diode VD4.

A charger for a mobile phone from the vehicle electrical system 12 volts.

The most common scheme of chargers for a mobile phone from a car cigarette lighter is made on a specialized microcircuit SP34063 (or its equivalent). This microcircuit with a minimum of hanging parts allows you to make a small charger for a mobile phone. There are charger circuits on discrete elements, one of which turned out to be in my possession, supposedly not working. A photograph of the printed circuit board is shown in Figure 1.

Using the printed conductors and the designations of the elements on the board, the charger circuit was restored (see Fig. 2).

According to the circuitry, the device is a pulse (relay) voltage stabilizer. After analyzing the circuit, it was decided to assemble a prototype board of the charger from more accessible Russian-made parts. As a result, a working layout was assembled, shown in Figure 3.

A diagram of such a device for domestic counterparts is shown in Figure 4.

About details:

Transistors KT626, KT502B, KT3102B, instead of a diode with a Schottky barrier type 1N5819, a KD212 (KD213) diode was installed. As an RF choke L1, a ring core with a diameter of 10 mm was used, soldered from a non-working motherboard of an IBM PC. Coil L1 on the ring is wound with MGTF mounting wire - until filled.

Device setup:

Resistor R3 sets the output voltage to ± 5 volts. Resistor R5 sets the device protection current, which disconnects the load, disrupting the operation of the switching regulator. Resistance R5 is selected by connecting several resistors in parallel, or made of high resistance wire (nichrome, manganin, etc.).
To simplify the circuit, resistor R5 and diode VD2 can be eliminated.

Cell phone car charger.

The diagram of a car charger for a cell phone from a car cigarette lighter is shown in the figure below.

The diagram of this device is typical and may slightly differ from individual manufacturers.
When plugging the charger into the cigarette lighter socket without a telephone, the green LED (G) is on. After connecting the phone, the red LED (R) lights up and the green one goes out. At the end of the charge, the green LED lights up, and the red one goes out accordingly.
A733 - can be replaced with KT3107;
VD1 - 1N5819 - Schottky diode (40V, 1A / 25A) DO-41 - analogue of SD1004 - looks like this:

Many modern cars have modules with multiple USB outputs for power. By and large, several USB ports are needed in any car, because so often you have to charge your phone, tablet, camera, and you also need to connect a navigator and a recorder.

It's high time to make a neat panel with USB sockets in the car. And to assemble it yourself is not at all difficult and not expensive, even for.

To build a USB power supply, you need at least:

1. microcircuit voltage regulator 5 V;
2. two capacitors: both at 25 V or only one, and the other at 10 V (the capacitance values \u200b\u200bof the capacitors depend on the selected stabilizer, and will be determined later);
3. 1 A semiconductor diode;
4. sockets types: 1USB-A or 2USB-A;
5. connecting wires of small cross-section - no more than 0.5 mm2

Microcircuit stabilizers voltages for assembling a USB power supply are preferred as they:

• are able to operate within a wide range of input voltages 7 - 20 V;
• have an overcurrent protection system;
• are equipped with an overheating protection system, which, when the chip of the microcircuit is heated, limits the output current.

One USB connector can be powered from the 78L05 stabilizer: Imax \u003d 0.1 A, Pmax \u003d 0.5 W, TO-92 case.

Two or more USB connectors must be connected to power supply from 78M05 or 7805 stabilizers.

The 78M05 microcircuit has the following characteristics: Imax \u003d 0.5 A, Pmax \u003d 7.5 W, TO-202 or TO-220 housing.

Chip 7805: Imax \u003d 1.5 A, Pmax \u003d 10 W, TO-220 case.

The 78 series regulators are manufactured in a package that makes them look like transistors.

The pinout for 78M05 and 7805 chips is as follows:

• the first output on the left is the input (if you look at the case from the side of the marking);
• medium - general;
• the third is the exit.

The 78L05 microcircuits have the opposite pinout than the 78M05 and 7805 microcircuits.

When assembling the circuit, it is necessary to take into account that the common output of the 78M05 and 7805 microcircuits is connected to their metal heat sink, therefore, when installing the stabilizer on the radiator, do not close the rest of the circuit elements. And it is still desirable to screw the microcircuit to the radiator, because the stabilizer in this case will work better (remember that microcircuit stabilizers limit the current at the load when overheating).

Semiconductor diodeit is needed to limit current surges when the switches or relay contacts are turned on, through which the stabilization circuit can be connected.

Capacitors you need to put 10 μF, and not 47 μF, if you use a less powerful 78L05 stabilizer in the circuit, and not 78M05 and 7805 microcircuits. By voltage, capacitors, as mentioned earlier, should be selected for 25 V each, or a capacitor at the output can be set to 10 V.

Light-emitting diode as a power indicator is not required, but it helps to visually determine the presence of voltage at the output and the serviceability of the stabilization circuit.

Resistorit is not necessary to set it to 160 ohms, because with such a damping resistance, the LED may shine too brightly. The damping resistor can be selected with resistances: 270 Ohm, 300 Ohm, 470 Ohm.

Having assembled the voltage stabilization circuit, you need to connect it to the USB socket: plus 5 V output - to the USB plus supply voltage; common output to - common connector pin.

The pinout for the USB sockets is as follows:

• the first contact on the left is common (if you look at the connector contacts from above);
• the second is plus data buses;
• third - plus data buses;
• fourth - plus supply voltage.

Of course, you will not transfer any data using the USB socket as a power source, so do not pay attention to the second and third pins of the connector.

Where to install the USB power sockets in the car is a personal decision of each craftsman. But as a recommendation, we can say that it is convenient to place several connectors together with the assembled circuit on a separate panel cut from a plastic or aluminum plate. Also on this small console, you can install a small switch that will cut off the voltage at the input of the stabilization circuit. Ready socket with uSB connectors very easy to install in a convenient place in the car.

Simple monoblock car amplifier on TDA1560Q Car throttle-free PSU on IRS2153 for laptops and mobile phones

In order to charge any portable device, such as a phone or tablet, from the car's 12-volt on-board network, you will have to use a DC-DC converter. But it is not necessary to buy an inverter when you can independently assemble, for example, a completely simple structure based on the 34063api microcircuit.

The IC is specially designed for this purpose, and many charger manufacturers use it as the main driver in car chargers. It was this microcircuit that became the base for the majority of "chargers" powered by a cigarette lighter.

The microcircuit has a built-in output stage that delivers a current of up to 3A to the load. Thanks to this, it can be considered universal - it is able to charge almost any mobile device, including devices with large batteries, such as tablet computers.

The microcircuit provides a stable output voltage of 5 volts. It is ideal for recharging the batteries of a wide variety of portable devices. The choke consists of 20 turns of 0.6 mm thick wire wound on a "dumbbell". The drops and surges of the on-board voltage are not terrible for the microcircuit, since the input voltage range is from 7 to 40 volts.

The microcircuit works stably even with sudden temperature changes and changes in weather, without overheating in the process. The 34063api can be connected in several ways. Here is the most reliable option that is simple and easy to reproduce.

A particularly valuable quality of this microcircuit is that it is possible to simultaneously connect to the output of several mobile phones. At the same time, the quality of charging, even if all models are different, will be no worse than through a standard device. You can also exclude input and output capacitors from the circuit, which are needed only to filter noise.