Car charger for mobile phone from cigarette lighter. Simple charger for tablets and cell phones in the car Homemade phone charger for the car
Sometimes it becomes necessary to charge a mobile phone from the car's on-board network. To do this, you can buy special chargers (cost $3-5), but it is much more interesting to make such a charger yourself.
The proposed design of a car charger for a mobile phone is quite simple and contains only a couple of components.
The required voltage is provided by the domestic low-power zener diode of the KS156A series.
The zener diode can be replaced with a similar one. In this circuit it does not heat up at all, so you can use zener diodes of any power. Radio amateurs often have questions about the marking of the zener diode. The specified zener diode has three different types of markings, but most often it is marked with an orange stripe on the cathode side and a white stripe on the anode side, usually found in a glass case, but it happens that more powerful ones come across - already in a metal version.
A powerful domestic transistor of the KT819 type (with any letter) was used as a power switch. Just in case, it is advisable to install the transistor on the heat sink, although when charging a mobile phone, the heat generation is not too bad. The transistor can be replaced with KT805, 817, 815 or powerful field switches. When replaced with field-effect transistors of the IRFZ44, IRFZ48, IRF3205 series and similar in power, then the need for heat removal in this case disappears.
I used a resistor with a power of 2 watts, but during operation it hardly heats up, so you can get by with a resistor with a power of 0.5-1 watt.
This design is capable of powering quite powerful loads. Can be used both for charging mobile devices and for powering low-voltage equipment from the vehicle's on-board network.
Of course, instead of the circuit, you can use integrated stabilizers of the 78XX series (to obtain 5 Volts of output voltage - 7805), but our circuit is more affordable and contains components that are lying around almost every corner.
A car charger is a very primitive device, consisting of only a few elements and capable of performing only one function: recharging a smartphone from the cigarette lighter while the car engine is running. However, despite the simplicity of a car phone charger, the choice of this accessory must also be approached very responsibly. A motorist using a low-quality charger runs the risk of finding himself without means of communication at any time - if a charging failure occurs during a long trip, this will become a real problem for the driver.
How to choose a car charger for a smartphone: basic criteria
First of all, the motorist must decide what he needs: full car charger or USB adapter. An adapter is an adapter from a cigarette lighter to a USB cable.
The adapter has a significant drawback: it turns into a completely useless thing if the motorist forgot the USB cable at home. Therefore, when contacting a communication store, the driver is recommended to take a full-fledged charger - it costs only a little more in retail than a USB adapter.
Other criteria for choosing an ASU include the following:
Output current. To charge smartphones you need a current of at least 1 A, and given modern smartphones this may not be enough, so the best option is 2 or 2.4 A per port. If you choose a charger with a current strength from 2 A, then the motorist will be able to recharge both a smartphone and a tablet. Worry about the fact that the smartphone is dated 2 A If it burns out, it shouldn’t: modern gadgets are equipped with special charging controllers - devices that do not allow excess current to pass through. In addition, a similar controller is installed in high-quality chargers.
Output voltage. There is such a rule: the voltage specified in the technical specifications of a car phone charger should not exceed the value indicated on the gadget’s battery by more than 5%. Otherwise, the ASU will overheat and very soon fail.
Wire length and type. Experts unanimously recommend taking an ASU with a twisted wire. The likelihood that the twisted wire will break (which could lead to a fire) is extremely low. In addition, the twisted wire is adjustable in length - a very useful feature considering how varied the interior of modern cars is.
Wire fastening. It is worth making sure that there is a corrugated sheath at the place where the wire comes out of the adapter. Here's what we mean:
The corrugated sheath prevents the wire from breaking at bend points. The fastening of the wire to the plug must also be protected by it.
Number of ports. This criterion is relevant if the motorist chooses a USB adapter. Optimal number of ports – 2 : both must have a current of at least 2 A. You can consider an ASU with a 1 A port, but only if the device is old or from the budget category.
In addition, we should not forget that in 2019 the vast majority of smartphones have a Type-C connector, so you can consider a charging option that has one USB-A output and a second.
Buying adapters with a large number of ports is advisable only for those motorists who are the heads of large or simply large families. Otherwise, the driver will pointlessly overpay for the accessory, because some of the ports will be idle.
Design. The driver should pay attention to the fact that there is no metal ring around the central contact of the AZU.
Since the charging body is most often made of plastic, the metal ring will sooner or later break off the thread and remain in the car’s cigarette lighter. A stuck part can short-circuit the contacts inside the cigarette lighter, which can lead to a fire. To be fair, it should be noted that AZUs with metal rings are now on sale very rarely, although previously a significant part of the chargers had just such a design.
A useful advantage from a design point of view is the presence of an LED, thanks to which the driver can be sure that the charger is working correctly. And in the dark, finding a charger is easier than trying to connect the cable by touch.
Otherwise, as far as design is concerned, the motorist should rely on his own opinion. For example, he may prefer a charger with an LED display informing about the state of charge and voltage of the car’s battery.
However, such an accessory will cost approximately more than a regular adapter.
What to buy: original or Chinese copy?
Buyers of expensive gadgets, as a rule, do not spare money on the best accessories - as long as nothing threatens their new mobile device. Such clients insist that they be provided with original chargers, cables and USB adapters, because they believe that universal chargers can cause damage to the device’s battery. But are they right?
More likely no than yes. If an iPhone XS buyer asks to sell him an original memory device, the consultant will probably offer an accessory from the company Belkin- but not Apple. By visiting the online store of the official retailer of Apple equipment in Russia Re:Store the buyer will find the company's ASU accessories in the catalog Deppa, MOMAX, Juicies, Anker– but again there is no charging made by Apple.
You won’t be able to find the original on the Apple company’s website either. In fact, this means that Apple does not produce its own RAMs. Belkin and other famous ones, of course, produce excellent accessories, but in relation to the iPhone this company is still a third-party manufacturer.
Anker PowerDrive 2 PD/PIQ A2229H12 (Black)
Price: from 2,590 rubles.
This stylish and compact model from Anker has an excellent range of useful features. The device has two outputs - a classic USB connector and an additional Type-C output. For ease of use at night, a blue backlight is provided - it allows you to see the AZU in the dark and at the same time will not distract the driver from driving the car with bright light.
Both connectors support Power Delivery and Power IQ functions, which are responsible for selecting the right power for different gadgets. In addition, the ASU is equipped with protection against overheating, overload and short circuit. For those who are worried about their device, and this is especially true for owners of expensive phones from Apple, Samsung and other famous manufacturers, this charger will be the best choice - you don’t have to worry that the battery will be damaged in any way or the device will burn out due to a power surge. There is no cable included, so it is recommended to use a proprietary cable from the smartphone manufacturer.
Anker PowerDrive 2 Elite A2212011 (Black)
Price: from 1290 rubles.
A simplified version of the previous model, which differs in the material used. Carbon fiber makes the body ergonomic and visually interesting. The model has illuminated ports, there are two of them, type - USB A. Both outputs support PowerIQ technologies (automatic power selection depending on the smartphone model) and VoltageBoost (speeds up the process of increasing battery capacity). In addition, there is protection against overheating, short circuit and overload. An excellent option for those who are looking for not the most expensive, but stylish and safe car charger for their mobile phone.
Conclusion
A driver choosing a car charger for a gadget should not pay attention to the price of the accessory and not look for the original charger, since in most cases they do not exist. It is much more important to look at the characteristics, as well as the level of safety, which comes down not only to the build quality, but to the materials used and the presence of protective controllers. Of course, a good charger costs a decent amount, but at the very least it is stupid to buy a car charger for 300-500 rubles for an iPhone for 100 thousand rubles.
In our technological age, it is difficult to imagine life without a phone. And what a disappointment it is when he sits down. If this happened at home or in the office, this is certainly not a problem, plug the charger into the outlet and that’s it. But when traveling in a car or when working in a job that involves constant travel, this will not be possible.
To do this, you need a charger in the car. Of course, you can buy it in the store, but we are not looking for easy ways, especially since assembling it is not a big problem.
The MC34063 chip will be taken as the basis; it is usually used in DC/DC voltage converters, i.e. from permanent to permanent.
Which is exactly what we need. As you know, the on-board power supply is 12 V, and the charger requires 5 V. Therefore, based on this microcircuit, we will assemble a voltage converter from 12 V to 5V. A schematic diagram of the future device is shown below.
The output voltage rating is set by the values of resistors R2 and R3. For the required value of 5 V, it is necessary to set R2=1 kOhm, R3=3 kOhm. The formula for determining the output voltage value is given below, so if you need to set the output voltage to a different voltage, you can use it to calculate.
In principle, you can make a universal adapter if you put a variable in place of R3 and unscrew the required value. The only thing is that before this you should do a calculation in order to understand in what range its values should be.
Resistor R1 plays the role of a current limiter, when setting R1 with a nominal value of 0.3 Ohm, exceeding the output current of more than 500 mA turns off the device, decreasing the resistance value will increase the shutdown current limit.
Capacitor C3 sets the operating frequency of the converter, the remaining capacitors are filtering ones. The inductor also acts as a filter, designed for a current of 1 A. 1N5819 was chosen as the diode, but the domestic analogue is quite suitable.
The adapter is assembled on the basis of the Z-43 case; its size is quite sufficient to compactly accommodate the entire element base. At the input we put the plug into the cigarette lighter and the output is a USB connector - you're done!
Buy ready-made charging to the phone not interested). Make with your own hands much more interesting, especially since such a simple and reliable device has already been tested. And she didn’t want to borrow the cigarette lighter. I found out about such a thing as KR142EN5A. Advantages of this microcircuit:
- Allowable output current 1A
- No external components required
- Internal thermal protection
- Output transistor protection
- Internal short circuit current limitation
The input voltage is up to 20 V, and the output is always 5 V. Actually, this is what is needed in order to reliably charge the phone battery. There is nothing complicated about assembly. We solder four wires to the circuit (we solder two terminals to the central leg - this will be “ground”). The left terminal is input “+”, the central one is ground, the right terminal is output “+”.
I had an old broken charger, I cut off the plug from it and soldered it to the microcircuit.” +" plug to the "+" output from KR142EN5A, and "-" plug to the ground of the circuit. It turns out that there is a common ground wire for the input and output. In the car I dragged the wires to a convenient place where the phone is always kept, and connected permanently via a button). I pressed the button, inserted the plug into the phone and started charging). Here I am posting photos...
But then I had to improve the circuit a little, since familiar “minds” recommended installing two 1000 uF capacitors. The result is this diagram. I recommend installing the condensers right away, although everything worked without them... And placing the microcircuit itself on a small radiator (just to be sure)
Modern mobile devices have already become an indispensable part of our lives. First of all, we are talking about phones and tablets. We use them everywhere, at home, on the street, in the car. In the car, they are also supplemented by navigators, video recorders, etc. What is needed for the normal operation of these devices? Of course there is power, because any battery, even a very good one, will eventually run out.
You can buy a ready-made USB charger for everything we use in the car. But there may be problems with the number of sockets, power, etc. As a rule, the charger's power is limited to a current of 0.5 A, although many are written at 1 A, but they are not able to withstand such a current.
As for my particular case, this charger, which is essentially a voltage stabilizer on the 7805 chip, was used to hide it under the instrument panel. As a result, having powered it from the cigarette lighter and hidden it under the instrument panel, only mini USB plugs were brought out to the instrument panel for the navigator and video recorder. This made it possible to provide power to gadgets while leaving the cigarette lighter sockets unoccupied. And perhaps the most important thing is to get rid of the wires that get in the way and their unsightly appearance.
So, in our article we will talk about an alternative, about making your own USB charger for a car based on a microcircuit - stabilizer 7805.
How to make a 1.5 Ampere USB charger in a car with your own hands (Option 1)
The voltage stabilizer of the L7805 series (current 1 A) or its analogue L7805CV (current 1.5 A) will be used as the “heart” of our charger. In fact, there can be a great variety of analogues used. In principle, the entire 7805 series of chips will be suitable for this. We will tell you more about analogues a little later.
The electrical circuit for connecting the stabilizer itself is simple; it is similar to the power stabilizer, which we talked about in our other article “Power stabilizer in a 12-volt car.” We can say that these are brother microcircuits, only their stabilization voltages are different.
Everything can be assembled either by surface mounting or on a board. It can be done on a regular, simple universal circuit board. In order for the microcircuit to develop its maximum supply current, it must be placed on a radiator. In our case, the radiator is taken from a computer processor.
The stabilizer microcircuits themselves can be produced in various packages. Possible housing options and analogues used are shown in the figure below.
Our assembly uses the TO-220 case... It is also possible to use microcircuits with the KIA 7805 index. A more detailed Data sheet for these microcircuits can be viewed.
Connecting a mini and micro USB plug from a charger in a car
After you have assembled the USB device, you need to connect the USB connectors correctly. You can take a wire with a factory-made mini, micro USB plug, or you can buy an “empty” plug in a store and solder the wire to it. The correct connection of different types of USB is shown in the figure below.
In my case, a mini USB plug was needed, which was soldered to the wire. The view is shown without the body.
Then, using a universal device, the voltage was checked again so as not to damage electronic gadgets. And then the battery of the audio player was already charged.
Subsequently, the charger was installed under the instrument panel, and mini USB plugs were brought out: one on the instrument panel for the navigator, the second under the roof for the DVR.
I apologize for the view in the garage.
A 5-volt car charger for a smartphone, navigator, DVR, tablet, built on the principle of PWM modulation (USB) at 4 Amps (Option 2)
However, the saga with the charger did not end there. Again, for a banal reason, when there is not enough supplied power or supply current for consumers, which is essentially the same thing, provided that the on-board voltage in the car is constant, since these values will be directly proportional.
So, during long-term joint use of the navigator and the DVR, one microcircuit was not able to “pull” the power from these two devices, even with a radiator installed. As a result, it overheated and briefly turned off. At the same time, the navigator “cussed” when the power was turned off.
There seem to be two solutions to the problem. The first is to “fence the garden” and create parallel circuits, each of which will have its own consumers. Let's say one is a DVR, the other is a navigator. In fact, in the photo above, where two microcircuits are mounted on one radiator, this is what was done. However, it’s good if everything is limited to this, and if you need to connect a smartphone, tablet, something else... There is no way to do without more serious currents, and therefore without alternative options. An alternative option would be to use microassemblies with PWM modulation. I won’t explain for a long time and in detail what this is, but the principle of all this is based on the fact that current is supplied to the load not constantly, but at a very high frequency. As a result, it becomes possible to reduce the heating of the microcircuit due to the very periods when it “rests”, and the load at such a high frequency perceives the power supply as constant, although it is not so...
So, such a scheme will not require large radiators for heat removal, and rather high currents will be provided. In general, everything will be as we need it. This option will be discussed further below. To reduce the voltage, a microcircuit, an inductor and elements for strapping are used. The microassembly is designated KIS3R33S,
Its installation can be done according to the diagram from Datasheet. However, by default with this configuration it has an output voltage of 3.3 volts, but for USB we need 5 volts.
In this case, it will be necessary to select resistors R1, R2. The table with recommended resistor values on which the supply voltage depends is also taken from the Datasheet. This feature of changing the voltage by selecting resistors makes this device a universal assistant if you need to power the load not only with a voltage of 5 volts as for USB.
It should be noted that this device confidently holds a load with a current consumption of 3A, and peak performance can reach 4A. If you are too lazy to assemble such a device, have no time, or cannot do it, then you can purchase such an assembly for about $2 on well-known sites and online stores.
I must say that this Chinese voltage converter KIS-3R33S (MP2307) is quite good for its price, and is capable of delivering high currents, which we already know, up to 4A. This means that such an assembly can replace a pair of KRENOK or the 7805 series, which we talked about in the first part of the article. At the same time, it will be more compact and with higher efficiency.
So, I bought this assembly. Then I also bought a distribution box, which are used for installing electrical wiring in apartments. This became the body of the converter - charger.
An LED was also attached in order to control whether voltage is supplied to this “box”. You can read about connecting an LED to 12 volts in a car in the article “How to connect an LED to 12 volts”. Everything was then installed under the dash, behind the glove box.
Connected to the cigarette lighter. Voltage appears on it only when the ignition is turned on, which is very successful for me.
The wires are still routed to the gadgets.
Now the charger current has increased to 4 Amps, which is still enough.
A special feature of this charger is that it can work both in passenger cars, where the on-board voltage is 12 volts, and in trucks, where it is 24 volts. At the same time, the charger does not require any modification or adjustment.