Homemade starting device for a car. Master class on making a starting device for a car with your own hands Simple starting charger 12 24 circuit
Winter, frost, the car won’t start, while we tried to start it, the battery is completely discharged, we are scratching our heads, thinking about how to solve the problem... Is this a familiar situation? I think those who live in the northern regions of our vast country have more than once encountered problems with their car in the cold season. And then such a case arises, we begin to think, it would be nice to have on hand a starting device designed specifically for such purposes.
It's natural to buy such a device industrial production is not a cheap pleasure, so the purpose of this article is to provide you with information on how you can make a starting device with your own hands using minimal costs.
The starting device circuit that we want to offer you is simple but reliable, see Figure 1.
This device is designed to start the engine vehicle with 12 volt on-board network. The main element of the circuit is a powerful step-down transformer. The bold lines in the diagram indicate the power circuits going from the starter to the battery terminals.
At the output of the secondary winding of the transformer there are two thyristors, which are controlled by a voltage control unit. The control unit is assembled on three transistors; the response threshold is determined by the value of the zener diode and two resistors forming a voltage divider.
The device works as follows. After connecting power wires to the battery terminals and the mains is turned on, no voltage is supplied to the battery. We begin to start the engine, and if U of the battery drops below the operating threshold of the voltage control unit (this is below 10 volts), it will give a signal to open the thyristors, the battery will receive recharge from the starting device.
When the voltage at the terminals reaches above 10 volts, the starting device will disable the thyristors and recharge the battery will stop. As the author of this design says, this method avoids harming the car battery.
Transformer for starting device.
In order to estimate how much power a transformer is needed for a starting device, you need to take into account that at the moment the starter starts, it consumes a current of about 200 amperes, and when it spins up, it consumes 80-100 amperes (voltage 12 - 14 volts). Since the starting device is connected directly to the battery terminals, when the car starts, some of the electricity will be supplied by the battery itself, and some will come from the starting device. We multiply the current by the voltage (100 x 14), we get a power of 1400 watts. Although the author of the above diagram claims that a 500-watt transformer is enough to start a car with a 12-volt on-board network.
Just in case, let us recall the formula for the ratio of wire diameter to cross-sectional area, this is the diameter squared multiplied by 0.7854. That is, two wires with a diameter of 3 mm will give (3*3*0.7854*2) 14.1372 sq. mm.
It doesn’t make much sense to provide specific data on the transformer in this article, because first you need to at least have more or less suitable transformer hardware, and then, based on the actual dimensions, calculate the winding data specifically for it.
The remaining elements of the scheme.
Thyristors: with a full-wave circuit - for a current of 80A and above. For example: TS80, T15-80, T151-80, T242-80, T15-100, TS125, T161-125, etc. When implementing the second option using a bridge rectifier (see diagram above), the thyristors must be 2 times more powerful. For example: T15-160, T161-160, TS161-160, T160, T123-200, T200, T15-250, T16-250 and the like.
Diodes:
for the bridge, choose ones that hold a current of about 100 amperes. For example: D141-100, 2D141-100, 2D151-125, V200 and the like. As a rule, the anode of such diodes is made in the form of a thick rope with a tip.
KD105 diodes can be replaced with KD209, D226, KD202, any with a current of at least 0.3 ampere will do.
The stabilization zener diode U should have about 8 volts, you can use 2S182, 2S482A, KS182, D808.
Transistors: KT3107 can be replaced with KT361 with a gain (h21e) greater than 100, KT816 can be replaced with KT814.
Resistors: In the circuit of the thyristor control electrode we place resistors with a power of 1 watt, the rest are not critical.
If you decide to make the power wires removable, ensure that the connection connector can withstand inrush currents. Alternatively, you can use connectors from a welding transformer or inverter.
The cross-section of the connecting wires coming from the transformer and thyristors to the terminals must be no less than the cross-section of the wire with which the secondary winding of the transformer is wound. It is advisable to install the wire connecting the starting device to a 220 volt network with a core cross-section of 2.5 square meters. mm.
In order for this starting device to work with cars whose on-board network has a voltage of 24 volts, the secondary winding of the step-down transformer must be designed for a voltage of 28...32 volts. The zener diode in the voltage control unit must also be replaced, i.e. D814A must be replaced with two D814V or D810 connected in series. Other zener diodes are also suitable, for example, KS510, 2S510A or 2S210A.
Hello all readers. Today we will consider the option of constructing a powerful switching power supply that provides an output current of up to 60 Amps at a voltage of 12 Volts, but this is far from the limit; if desired, you can pump out currents of up to 100 Amps, this will give you an excellent start-up. Charger.
The circuit is a typical push-pull half-bridge network, step-down pulse source nutrition, this is the full name of our block. our favorite microcircuit IR2153 is used as a master oscillator. The output is supplemented with a driver, essentially a regular repeater based on complementary pairs BD139/140. Such a driver can control several pairs of output switches, which will make it possible to remove more power, but in our case there is only one pair of output transistors. 
In my case, powerful n-channel field-effect transistors of type 20N60 with a current of 20 Amperes are used, the maximum operating voltage for these switches is 600 volts, they can be replaced with 18N60, IRF740 or similar, although I don’t really like the 740s because of the upper voltage limit of everything at 400 volts, but they will work. The more popular IRFP460 are also suitable, but the board is designed for keys in the TO-220 package. 
A unipolar rectifier with a midpoint is assembled in the output part; in general, to save the transformer window, I recommend a regular one diode bridge install, but I didn’t have any powerful diodes, instead I found Schottky assemblies in a TO-247 package of type MBR 6045, with a current of 60 Amps, installed them, to increase the current through the rectifier, I connected three diodes in parallel, so our rectifier can easily pass currents up to 90 Amperes, a completely normal question arises - after all, there are 3 diodes, each 60 Amperes, why 90? The fact is that these are Schottky assemblies, in one case there are 2 diodes of 30 amperes each connected with a common cathode. If anyone doesn’t know, these diodes are from the same family as the output diodes in computer power supplies, only their currents are much higher. 
Let's take a superficial look at the principle of operation, although I think for many everyone is clear. 
When the unit is connected to a 220 Volt network through the R1/R2/R3 chain and the diode bridge, the main input electrolytes C4/C5 are smoothly charged, their capacity depends on the power of the power supply, ideally a capacitance of 1 μF per 1 watt of power is selected, but some variation is possible in one direction or another, capacitors must be designed for a voltage of at least 400 Volts. 
Through resistor p5, power is supplied to the pulse generator. Over time, the voltage on the capacitors increases, the supply voltage for the ir2153 microcircuit also increases, and as soon as it reaches a value of 10-15 Volts, the microcircuit starts up and begins to generate control pulses, which are amplified by the driver and supplied to the gates field effect transistors, the latter will operate at a given frequency, which depends on the resistance of resistor r6 and the capacitance of capacitor c8.
Of course, voltage appears on the secondary windings of the transformer, and as soon as it is of sufficient magnitude, the composite transistor KT973 opens, through the open transition of which power is supplied to the relay winding, as a result of which the relay will operate and close contact S1 and the mains voltage will already be supplied to the circuit not through resistors R1, R2, R3 and on the relay contacts.. 
This is called a soft start system, more precisely a delay when turning on, by the way, the relay response time can be adjusted by selecting a capacitor C20, the larger the capacitance, the longer the delay. 
By the way, at the moment the first relay operates, the second one also operates; before it operates, one end of the transformer’s network winding was connected to the main power supply through resistor R13. 
Now the device is already operating in normal mode, and the unit can be overclocked to full power.
Low-current output 12 Volts in addition to powering the circuit soft start can power a cooler to cool the circuit.
The system is equipped with a short circuit protection function at the output. Let's consider the principle of its operation.
R11/R12 acts as a current sensor; in the event of a short circuit or overload, a voltage drop of sufficient magnitude is formed across them to open the low-power thyristor T1; when it opens, it short-circuits the plus supply for the generator microcircuit to ground, so the microcircuit is not supplied with supply voltage and it stops working. Power is supplied to the thyristor not directly, but through an LED; the latter will light when the thyristor is open, indicating the presence of a short circuit. 
In the archive printed circuit board slightly different, designed to produce bipolar voltage, but I think converting the output part to unipolar voltage will not be difficult.
Archive for the article; download…
That's all, I was with you as always - Aka Kasyan
,
The battery is a faithful friend and assistant in the most difficult situations, but, unfortunately, it does not last forever. It would be okay if the battery died instantly, without hope of recovery. But it gradually loses its characteristics, so it often turns out that it is simply impossible to turn the starter. The peak of battery failure occurs in winter, when it is especially difficult for equipment to start in cold weather. And then either a neighbor in the garage comes to the rescue with wires for lighting, or a spare battery. Or a good starting device, which every thrifty car enthusiast has.
Types of starting devices
Having some skills in radio electronics, we assemble a starting device for a car with our own hands. We will show drawings and photos, but first we will decide on its type, since they are different. Regardless of the type, it is important for us, as users, that the PU can work without the help of a battery and starts the engine not at the limit of its capabilities, turning red and smoking, but working stably even in severe frost. Exactly this important condition when choosing a ready-made charging and starting device or assembling it yourself.
There is no special pickle here. The mechanism can be one of four types:
- pulse;
- transformer;
- battery;
- capacitor.
The essence of the work of each of them ultimately comes down to supplying the on-board electrical network with a current of the required rating and voltage, 12 or 24 volts, depending on the type of electrical equipment on board.
Transformer control panel, parameters
Transformer PUs are popular among DIYers. There is probably no need to explain the principle of their operation - it is a transformer that converts network electricity to the required parameters. These devices have one disadvantage - their enormous size and weight. But they are reliable and change the output parameters for voltage and current as needed. They are quite powerful and start the engine even with a dead battery. The simplest drawing for a transformer based starter is shown below.
How to choose a transformer
To make the device yourself, it is enough to find a suitable transformer, and for a reliable start it must produce at least 100 A and a voltage of 12 V, if we are talking about a passenger car. If you ask a fifth grader, he will be able to calculate the power. In our case, it is 1.2, or better yet 1.4 kW. Without a battery, it will hardly be possible to start the engine with such a current, because the starter needs at least 200 A. A standard battery will help spin the crankshaft, and while rotating, the starter consumes no more than 100 A, which is what our device will produce.
The core area cannot be less than 37 cm², and the primary winding wire must be at least 2 mm². The secondary is wound copper wire with a cross section of 10 squares, and the number of turns is selected experimentally so that the open circuit voltage is no more than 13.9V.
Diagram and details of PU assembly
Calculating the parameters of a transformer is not all. The device works like this. We connect the power wires directly to the battery terminals, while there is no voltage at the output of the control unit until the battery voltage drops below the response threshold of the thyristors, which are indicated in the diagram. As soon as the voltage at the battery terminals drops, the thyristors open the input and only then the electrical equipment is powered by the device. As soon as the voltage at the battery terminals rises to 12 V, the thyristors close and the device automatically turns off. This allows you to save the battery from overload.
The thyristor version can be assembled using two methods - using a full-wave circuit and using a bridge circuit. If the rectifier is a bridge rectifier, then the thyristors must be selected twice as powerful. That is, according to the first scheme, thyristors are designed for a minimum of 80 A, and with a bridge circuit - a minimum of 160 A. Diodes are designed for a current of at least 100 A. These elements are easily recognized by their braided output tip. The KT3107 transistor can be replaced with the 361st. There is only one requirement for resistance in the control circuit - their power must be at least one Watt.
The output wires, naturally, must correspond to the current and, as a rule, for this they take an analogue from welding machine. Naturally, they are no thinner than the secondary wire. The wire that connects the network has a cross-section of each core of at least 2.5 square millimeters. A simple and reliable assembly that will start the engine in any frost. However, there are other options that you can buy in the store.
Pulse charger starting device
A pulse device is an excellent option when you need to constantly monitor the battery and keep it in working condition. Such designs operate on the principle of pulsed current conversion, and they are assembled on microprocessors and controllers. It cannot show much power, so it may not be suitable for starting, especially at severe subzero temperatures, but it is excellent for charging batteries.
They are compact, low in price, weigh very little and look nice. But the low power, or rather the low starting current that they produce, will not allow you to start the car with heavily discharged banks in the cold. In addition, precision electronics do not tolerate voltage surges and current frequency surges, which are not uncommon in our networks, and if something happens, not even every workshop can repair such a device.
Mobile control units
Another type of PU, or rather two at once, similar in principle of operation - battery and capacitor. A capacitor device works by discharging charged capacitors upon command. Their composition cannot be called particularly complex, but capacitors of such ratings themselves are quite expensive and cannot be restored after damage or drying out. They are used very rarely, although they are quite mobile, but due to high unregulated currents there is a risk of harming the battery.
Boosters, or battery starters, work even simpler. By and large, this is just an additional battery in a self-contained case. It was their autonomy that brought them popularity. They can be used even in the steppe, where there is no electricity. The pre-charged battery is connected to the on-board power supply and quietly starts the engine. In this case, it is important to choose the booster capacity and its starting current. It cannot be less than that of a standard battery. Household stand-alone installations have a capacity of 18 A/h, and more expensive and bulky, professional devices can have a capacity of about 200 A/h.
Any of these driver assistants will help start the engine, but there is nothing more reliable and cheaper than a transformer PU assembled by yourself. Good luck to everyone and have a quick start!
Every motorist has probably found himself in a situation where his car did not start at the moment when he needed to go somewhere urgently. This happens especially often in winter time when the temperature outside is sub-zero. Anyone can buy a modern model of a car starter charger in a store, but the problem is that a high-quality and reliable device is very expensive, and inexpensive devices quickly break down.
Making your own starter charger is not that difficult. The main thing is to buy everything necessary details in any radio parts store. At the same time, the assembled device for the car is much cheaper and meets all the needs of the motorist.
Selecting a device diagram
You can select the appropriate circuit for the charger on specialized Internet sites and forums, where you will also find detailed description all functions. If you have never assembled such devices yourself before and you do not have experience, stop at simpler circuits. When choosing a circuit, attention should be paid to the presence of a switch or other device that turns off the ammeter during start-up mode.
Various sites suggest making or assembling a step-down transformer with your own hands, but this is a rather complicated process that requires some skills. Thus. It’s better to buy a suitable transformer from the factory - this way you will save your time and nerves. A step-down transformer is the basis of a car starter charger, so it’s better not to skimp on it.
Materials and tools
To assemble the starter charger yourself at home or in the garage, you will need the following tools, materials and equipment:
- soldering iron of sufficient power;
- textolite plate;
- tin solder;
- a step-down transformer;
- radio components;
- cooler or case fan;
- wires high voltage cross section 2-2.5 square;
- screwdriver or drill with drill bits;
- wires for connecting to the battery with a cross-section of at least 10 square copper with clamps;
- fastening elements.
About assembling the device
You need to assemble the charger for the car on a sheet of textolite of the appropriate size. You need to start with a step-down transformer, since this is the most bulky part in the device you are assembling. To fasten parts and pass wires, holes of a suitable diameter are drilled in the textolite plate. For rectifier diodes, it is necessary to provide a reliable cooling system. This requires special metal cooling jackets. Sometimes this may not be enough, so you should consider additional forced cooling using a case fan from the computer.To remove heat, provide heat-dissipating blinds in the housing, which you can make yourself.
Some motorists believe that the assembled charger does not need to be enclosed in a housing, but it provides protection for the equipment from external influences and also protects the owner from electric shocks. A case from an old personal computer works well as a fencing for the charger. With some modifications, you can give your device a complete look. Indicators, switches and all controls can be built into the front panel of the case.
Shown in Fig. Starting devices 1 and 2 work effectively when connected in parallel to the battery and provide a current of at least 100 A at a voltage of 12 - 14 V. In this case, the rated power of the T1 network transformer used is 800 W.
To manufacture a network transformer, it is convenient to use toroidal iron from any LATR - this results in minimal dimensions and weight of the device. The perimeter of the iron cross-section can be from 230 to 280 mm (for different types Autotransformers are different). As is known, the rated operating power of a transformer depends on the cross-sectional area of the magnetic core (iron) at the location of the windings.
You need to carefully disassemble the case laboratory autotransformer, remove the contact slider, and wind the secondary winding with a thick wire in rubber insulation, approximately 18 hours - 25 turns (depending on the type of LATR), with a wire with a cross-section of at least 7 mm^2 (can be multi-core).
Then, from this winding, supply current to the car through a single-wave rectifier on a power diode type D161-250, observing the polarity.
Rice. 1. Starting device(option 1).
Since the second version of the starting device involves rewinding the primary winding, before winding the windings it is necessary to round off the sharp edges on the edges of the magnetic circuit with a file, and then wrap it with varnished cloth or fiberglass.
The primary winding of the transformer contains approximately 260 - 290 turns of PEV-2 wire with a diameter of 1.5 - 2.0 mm (the wire can be of any type with varnish insulation). The winding is distributed evenly in three layers, with interlayer insulation.
After completing the primary winding, the transformer must be connected to the network and the no-load current must be measured. It should be 200 - 380 mA. In this case, there will be optimal conditions for transforming power into the secondary circuit.
If the current is less, part of the turns must be rewinded; if more, it must be rewinded until the specified value is obtained.
The relationship between inductive reactance (and therefore the current in the primary winding) and the number of turns is quadratic - even a slight change in the number of turns will lead to a significant change in the primary winding current.
There should be no heating when the transformer is operating in idle mode. Heating of the winding indicates the presence of interturn short circuits or pressing and short-circuiting of part of the winding through the magnetic core. In this case, the winding will have to be done again.
The secondary winding is wound with insulated stranded copper wire with a cross-section of at least 6 mm^2 (for example, PVKV type with rubber insulation) and contains two windings of 15 - 18 turns. The secondary windings are wound simultaneously (with two wires), which makes it easy to obtain the same voltage in both windings, which should be in the range of 12 - 14 V at a nominal mains voltage of 220 V.
It is better to measure the voltage in the secondary winding using a load resistor with a resistance of 5 - 10 Ohms temporarily connected to terminals X1, X2.
Rice. 2. Starting device (option 2).
The connection of rectifier diodes allows the use of metal elements of the starter housing as a heat sink without dielectric spacers.
To connect the starting device parallel to the battery, the connecting wires must be insulated and stranded, with a cross-section of at least 10 mm^2.
Switch SA1 is type T3, or any other, the contacts of which are designed for a current of at least 5 A. It is convenient to use a PAR-10 automatic fuse as a switch.
Note. If you add another winding to any of the presented starting devices (25 - 30 turns of PEV-2 wire with a diameter of 2 mm), and use it to power one of the charger circuits below, then the “starters” will become starting-chargers.
