The starting charger allows you to start your car engine in winter. Since starting an internal combustion engine with a dead battery requires a lot of effort and time. The density of the electrolyte noticeably decreases in winter, and the sulfation process occurring inside the battery increases its internal resistance and reduces the starting current of the battery. In addition, in winter, the viscosity of engine oil increases, so the battery requires more starting power. To make it easier to start the engine in winter, you can warm up the oil in the crankcase of the car, start the car from another battery, start it “with a pusher”, or use a starting charger for the car.

The starting charger for a car consists of a transformer and powerful rectifier diodes. For normal operation of the starting device, an output current of at least 90 amperes and a voltage of 14 volts are required, so the transformer must be powerful enough, at least 800 W.

To make a transformer, it is easiest to use a core from any LATR. The primary winding should be from 265 to 295 turns of wire with a diameter of at least 1.5 mm, preferably 2.0 mm. Winding must be done in three layers. There is good insulation between layers.

After winding the primary winding, we test it by connecting it to the network and measure the no-load current. It should be between 210 - 390 mA. If it is less, then rewind a few turns, and if it is more, then vice versa.

The secondary winding of the transformer consists of two windings and contains 15:18 turns of stranded wire with a cross-section of 6 mm. The windings are wound simultaneously. The voltage at the output of the windings should be about 13 volts.

Wires connecting the device to the battery must be multi-core, with a cross-section of at least 10 mm. The switch must withstand a current of at least 6 Amps.

The starting circuit of a car charger contains a triac voltage regulator, a power transformer, a rectifier with powerful diodes and a starter battery. The charging current is set by the current regulator on the triac and is regulated by variable resistance R2 and depends on the capacity of the battery. The input and output charging circuits contain filter capacitors, which reduce the degree of radio interference during operation of the triac regulator. The triac operates correctly at mains voltages from 180 to 230 V.

The rectifier bridge synchronizes the switching on of the triac in both half-cycles of the mains voltage. In the “Regeneration” mode, only the positive half-cycle of the mains voltage is used, which cleans the battery plates from existing crystallization.

The power transformer was borrowed from the Rubin TV. You can also take the TCA-270 transformer. We leave the primary windings unchanged, but we will redo the secondary windings. To do this, we separate the frames from the core, unwind the secondary windings to the foil of the screens, and in their place wind them with copper wire with a cross-section of 2.0 mm in one layer until the secondary windings are filled. As a result of rewinding, approximately 15 ... 17 V should come out

When adjusting, an internal battery is connected to the starting charger, and the charging current adjustment is tested with resistance R2. Then we check the charging current in charge, start and regeneration modes. If it is no more than 10...12 amperes, then the device is in working condition. When the device is connected to a car battery, the charging current initially increases by about 2-3 times, and after 10 - 30 minutes it decreases. After this, switch SA3 is switched to the “Start” mode, and the car engine starts. If the attempt is unsuccessful, we additionally recharge for 10 - 30 minutes and try again.

The diagram contains: stabilized power supply(diodes VD1-VD4, VD9, VD10, capacitors C1, SZ, resistor R7 and transistor VT2)

synchronization node(transistor VT1, resistors R1/R3/R6, capacitor C4 and elements D1.3 and D1.4, made on the K561TL1 microcircuit);

pulse generator(elements D1.1, D1.2, resistors R2, R4, R5 and capacitor C2);

pulse counter(chip D2K561IE16);

amplifier(transistor VT3, resistors R8 and R9);

power unit(optocoupler thyristor modules VS1 MTO-80, VS2, power diodes V-50 VD5-VD8, shunt R10, instruments - ammeter and voltmeter);

short circuit detection unit(transistor VT4, resistors R11-R14).

The scheme works as follows. When voltage is applied at the output of the bridge (diodes VD1-VD4), a half-wave voltage appears (graph 1 in Fig. 2), which, after passing through the circuit VT1-D1.3.-D1.4, is converted into pulses of positive polarity (graph 2 in Fig. 2). These pulses for counter D2 are a reset signal to the zero state. After the reset pulse disappears, the generator pulses (D1.1, D1.2) are summed up in counter D2 and when the number 64 is reached, a pulse appears at the counter output (pin 6) with a duration of at least 10 generator pulse periods (graph 3, Fig. 2). This pulse opens the thyristor VS1 and voltage appears at the output of the ROM (graph 4 in Fig. 2). To illustrate the limits of voltage regulation, graph 5 of Fig. 2 shows the case of setting almost the full output voltage.

With the parameters of the frequency-setting circuit (resistors R2, R4, R5 and capacitor C2 in Fig. 1), the opening angle of the thyristor VS1 lies within 17 (f = 70 kHz) - 160 (f = 7 kHz) electrical degrees, which gives the lower limit of the output voltage about 0.1 times the input value. The frequency of the generator output signals is determined by the expression

f=450/(R 4 +R 5)С 2

,

where the dimension f is kHz; R - kOhm; C - nF. If necessary, the ROM can be used to regulate only the AC voltage. To do this, the bridge on diodes VD5-VD8 should be excluded from the circuit (Fig. 1), and the thyristors should be connected back-to-back (in Fig. 1 this is shown by the dashed line).

In this case, using the circuit (Fig. 1), you can regulate the output voltage from 20 to 200 V, but it should be remembered that the output voltage is far from sinusoidal, i.e. Only electric heating devices or incandescent lamps can serve as a consumer. In the latter case, you can sharply increase the service life of the lamps, since they can be turned on smoothly by changing the voltage from 20 to 200 V with resistor R5. Setting up the ROM comes down to adjusting the level of protection against short circuit currents. To do this, remove the jumpers between points A and B (Fig. 1) and temporarily apply +Up voltage to point B. By changing the position of the slider of resistor R14, we determine the voltage level (point C in Fig. 1) at which transistor VT4 opens. The protection response level in amperes can be determined by the formula I>k /R10, where k=Up/Ut.c., Up - supply voltage; Ut.s. - voltage at point C at which VT4 is triggered; R10 - shunt resistance.

In conclusion, we can recommend the procedure for putting the ROM into operation and inform about possible replacements of components, tolerances and manufacturing features: the D1 microcircuit can be replaced with the K561LA7 microcircuit; microcircuit D2 - microcircuit K561IE10, connecting both counters in series; all resistors in the MLT type circuit are 0.125 W, with the exception of resistor R8, which must be at least 1 W; tolerances on all resistors, with the exception of resistor R8, and on all capacitors +30%; the shunt (R10) can be made of nichrome with a total cross-section of at least 6 mm (total diameter about 3 mm, length 1.3-1.5 mm). Put the ROM into operation only in the following sequence: turn off the load, set resistor R5 to the required voltage, turn off the ROM, connect the load and, if necessary, increase the voltage with resistor R5 to the required value.

To solve the problem of starting the engine in winter, we will use an electric starter that will allow motorists to start a cold engine even with a partially charged battery and thereby extend its life.

Calculation. Carrying out an accurate calculation of the magnetic core of the transformer is impractical, since it is under load for a short time, especially since neither the grade nor the technology for rolling the electrical steel of the magnetic core is known. Find the required power of the transformer. The main criterion is the operating current of the electric starter Istart, which is in the range of 70 - 100 A. Electric starter power (W) Rap = 15 Istart. Determine the cross-section of the magnetic circuit (cm 2) S = 0.017 x Rap = 18...25.5 cm2. The electric starter circuit is very simple; you just need to correctly install the transformer windings. To do this, you can use toroidal iron from any LATRA or from an electric motor. For the electric starter, I used the transformer iron of an asynchronous electric motor, which I chose taking into account the cross section. The parameters S = aw must be no less than the calculated ones.

The stator of the electric motor has protruding grooves that were used for laying the windings. When calculating the cross section, do not take them into account. You need to remove them with a simple or special chisel, but you don’t have to remove them (I didn’t remove them). This only affects the consumption of the electrical wires of the primary and secondary windings and the mass of the electric starter. The outer diameter of the magnetic core is in the range of 18 - 28 cm. If the cross-section of the electric motor stator is larger than the calculated one, it will have to be divided into several parts. Using a metal hacksaw, we saw through the outer ties in the grooves and separate the torus of the required cross-section. Use a file to remove sharp corners and protrusions. We carry out insulating work on the finished magnetic circuit using varnished cloth or fabric-based insulating tape.

Now we proceed to the primary winding, the number of turns of which is determined by the formula: n1 = 45 U1/S, where U1 is the voltage of the primary winding, usually U1 = 220 V; S is the cross-sectional area of ​​the magnetic circuit.

For it we take copper wire PEV-2 with a diameter of 1.2 mm. We first calculate the total length of the primary winding L1. L1 = (2a + 2b) Ku, where Ku is the stacking coefficient, which is equal to 1.15 - 1.25; a and c are the geometric dimensions of the magnetic circuit (Fig. 2).

Then we wind the wire onto the shuttle and install the winding in bulk. Having connected the leads to the primary winding, we treat it with electrical varnish, dry it and carry out insulation work. Number of turns of the secondary winding n2 = n1 U2/U1, where n2 and n1 are the number of turns of the primary and secondary windings, respectively; U1 and U2 - voltage of the primary and secondary windings (U2 = 15 V).

The winding is made with insulated stranded wire with a cross-section of at least 5.5 mm2. The use of busbar trunking is preferable. Inside the wire we place turn to turn, and on the outside with a small gap - for uniform placement. Its length is determined taking into account the dimensions of the primary winding. We place the finished transformer between two square getinaks plates 1 cm thick and 2 cm wider than the diameter of the wound transformer, having previously drilled holes in the corners for fastening with coupling bolts. On the top plate we place the leads of the primary (insulated) and secondary windings, a diode bridge and a handle for transportation. We connect the outputs of the secondary winding to the diode bridge, and equip the outputs of the latter with M8 wing nuts and mark them “+”, “-”. The starting current of a passenger car is 120 - 140 A. But since the battery and electric starter operate in parallel mode, we take into account the maximum electric starter current of 100 A. Diodes VD1 - VD4 type B50 for a permissible current of 50 A. Although the engine starting time is short, it is advisable to place diodes on radiators. We install any switch S1 with a permissible current of 10 A. The connecting wires between the electric starter and the motor are multi-core, with a diameter of at least 5.5 mm in different colors, and we equip the ends of the output tips with alligator clips.

Start-charger PZU-14-100

The diagram of the starting-charger clearly shows that the thyristors are controlled by current pulses of the circuit capacitance C4 - transistors VT5, VT6, VT7 - diodes VD4, VD5. The unlocking phase of the thyristors and the flow of current in the power circuit depend on the rate of increase in voltage across the capacitor C4, that is, on the current through the resistances of the current regulator R23-R25 and through the start bipolar transistor VT3. VT3 turns on in the “start” mode if the voltage on the battery drops below 11 V. The key transistor VT4 turns on the control circuit when properly connected to the battery and protects it when the current is exceeded and the windings overheat. For reliable operation of this circuit, the halves of the secondary winding are required to be as identical as possible; they are usually made by winding them into two wires or by dividing the ends of the “pigtail” in two. The current flowing in the winding is measured by the voltage difference on the loaded and free halves, since they are loaded in turn.

Motorists and drivers are familiar with the situation of starting cars in winter, especially if the car battery is “not the first freshness” and the temperature outside is far from above zero.
If it is possible to “supply” the mains voltage to the car with extension cables, or even better, when the car is in an electrified garage, a starting device is offered to help.

Recently, problems arose with batteries and it was necessary to figure out how to start cars in a timely manner and without problems. To do this, a starting device was needed.
The existing circuit solutions turned out to be complex and in a corner remote from the Mitinsky radio market, finding the necessary radio elements turned out to be problematic. Therefore, the device below was developed using radio elements from old Soviet household appliances, and of course the transformers and thyristors were from decommissioned military equipment.
This device was designed for operation by “highly competent” specialists, so some of the elements there are, in principle, superfluous. Such a device worked in car pits for more than 12 years, and the “operators” failed to burn it during this time.
The starting device diagram is shown below.

The principle of its operation is as follows; - when you connect it to the car battery, it is “silent”. After the voltage on the battery drops below 10 volts when the car is started, the thyristors open and the battery is recharged from the network. As soon as the engine starts and the battery voltage rises above 10 volts, it turns off.

As a transformer, you can use any suitable one with a power of at least 500 Watts, and with a cross-section of the secondary winding wires of at least 2x7 sq. mm (7 sq. mm is a wire with a diameter of 3 mm), or for a bridge rectifier circuit of 14 sq. mm with an output voltage 15-18 volts, optimal voltage is about 18 volts.
I don’t see any point in describing the procedure for making a transformer; you need specific hardware, and then there are calculations for it.
As thyristors, you can use any with a current of at least 80 amperes (T-15-80, T15-100, T-80, T-125, T142-80, T242-80, T151-80, T161-125 and others) , or at least 160 amperes with a bridge rectifier circuit (T15-160......T15-250, T16-250.....T16-500, T161-160, T123-200....T123-320 ,T161-160, T160, T200, and others). The diodes in the bridge rectifier circuit must also be designed for a current of at least 80 amperes (D131-80, D132-80, 2D131-80, 2DCh151-80, D141-100, 2D141-100, 2D151-125, V200, V7-200 and others). You need to focus on the thick wire sticking out of the diode (as thick as a finger) or the second digit in the designation of the diode brand, usually, but sometimes the first.
Instead of KD105 diodes, you can use any rectifier with a current of at least 0.3 A (D226, D237, KD209, KD208, KD202, from the rectifier of any Chinese adapter, even network ones).
Zener diode D814A can be replaced with any one, but with a stabilization voltage of about 8 volts (D808, 2S182, KS182, 2S482A, 2S411A, 2S180).
Transistors, in the first version, instead of KT3107, KT361 with h21e more than 100 was used, instead of KT816, KT814, and even P214 are suitable, you can also use KT825, KT973, KT818. Resistors (except for thyristor control) of any power. The sections of the circuit highlighted in the diagram with bold lines must be made of conductors with a cross-section of at least 10 sq. mm., the entire starting current will flow through them.
Here is a version of the device on a printed circuit board by our user Serg_K

This circuit with the indicated ratings and voltages is designed for 12-volt equipment, but it can also be used for 24-volt equipment; for this you need a transformer with an output voltage of 28-32 Volts and the D814A zener diode must be replaced with two D814V connected in series, or the other two have a stabilization voltage of about 10 volts (D810, D814V, 2S210A, 2S510A, KS510).

You can check the device like this;

Connect a car lamp to the output of the device, maybe not a very powerful one, for example. depending on the size, it is better to put two in series or one at 24 volts.
Next, connect, observing polarity, instead of the battery to the lamp - an regulated power supply, preferably without electrolytic capacitors at the output.
A charger with a thyristor regulator is not suitable as an adjustable power supply, since it produces voltage pulses at the output that are adjustable in duration, but the voltage needs to be adjusted in amplitude.
Next, turn on the power supply and set the voltage to 13V (the lamp is on).
Next, turn on the launcher - nothing should change.
Next, gradually reduce the power supply voltage (the lamp intensity decreases) and when the power supply voltage reaches around 10 volts (plus or minus a volt), the starting voltage should start, i.e. the intensity of the lamp will increase sharply and voltage will be supplied to it from the starting trance - 18 volts (therefore, a 24V lamp is better).
Further, if you start increasing the power supply voltage again, the starting voltage should turn off (the lamp intensity will decrease).
That's all the setup.

Of the real designs, a transformer with a power of 500 watts is enough to start a passenger car; a 24-volt version with a transformer power of 2 kW could easily start a MANN truck tractor. Network wires must have a cross-section of at least 2.5 sq. mm.
Looks like I wrote everything.

If you have any “misunderstandings” regarding the article, ask questions, I will help you figure it out and answer your questions.

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.

Naturally, buying such an industrially produced device 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 at minimal cost.

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 of a vehicle with a 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 the power wires to the battery terminals and turning on the mains, 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 put 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.

Starting the internal combustion engine of even a passenger car in winter, and even after a long period of parking, is often a big problem. This issue is even more relevant for powerful trucks and tractor-trailer equipment, of which there are many already in private use - after all, they are operated mainly in conditions of garage-free storage.

And the reason for difficult starting is not always that the battery is “not in its first youth.” Its capacity depends not only on the service life, but also on the viscosity of the electrolyte, which, as is known, thickens with decreasing temperature. And this leads to a slowdown in the chemical reaction with its participation and a decrease in the battery current in starter mode (by about 1% for each degree of temperature decrease). Thus, even a new battery significantly loses its starting capabilities in winter.

Do-it-yourself starting device for a car

To insure against unnecessary hassle associated with starting a car engine in the cold season, I made a starting device with my own hands.
The calculation of its parameters was carried out according to the method specified in the list of references.

The operating current of the battery in starter mode is: I = 3 x C (A), where C is the nominal battery capacity in Ah.
As you know, the operating voltage on each battery (“can”) must be at least 1.75 V, that is, for a battery consisting of six “cans,” the minimum operating voltage of the Up battery will be 10.5 V.
Power supplied to the starter: P st = Uр x I р (W)

For example, if a passenger car has a 6 ST-60 battery (C = 60A (4), Rst will be 1890 W.
According to this calculation, according to the scheme given in, a launcher of the appropriate power was manufactured.
However, its operation showed that it was possible to call the device a starting device only with a certain degree of convention. The device was capable of operating only in the “cigarette lighter” mode, that is, in conjunction with the car’s battery.

At low outside temperatures, starting the engine with its help had to be done in two stages:
- recharging the battery for 10 - 20 seconds;
- joint (batteries and devices) engine promotion.

An acceptable starter speed was maintained for 3 - 5 seconds, and then decreased sharply, and if the engine did not start during this time, it was necessary to repeat it all over again, sometimes several times. This process is not only tedious, but also undesirable for two reasons:
- firstly, it leads to overheating of the starter and increased wear;
- secondly, it reduces the battery life.

It became clear that these negative phenomena can be avoided only when the power of the launcher is sufficient to start a cold car engine without the help of a battery.

Therefore, it was decided to manufacture another device that satisfies this requirement. But now the calculation was made taking into account losses in the rectifier unit, supply wires and even on the contact surfaces of the connections during their possible oxidation. One more circumstance was also taken into account. The operating current in the primary winding of the transformer when starting the engine can reach values ​​of 18 - 20 A, causing a voltage drop in the supply wires of the lighting network by 15 - 20 V. Thus, not 220, but only 200 V will be applied to the primary winding of the transformer.

Diagrams and drawings for starting the engine

According to the new calculation according to the method specified in, taking into account all power losses (about 1.5 kW), the new starting device required a step-down transformer with a power of 4 kW, that is, almost four times more than the power of the starter. (Corresponding calculations were made for the manufacture of similar devices intended for starting the engines of various cars, both carburetor and diesel, and even with a 24 V on-board network. Their results are summarized in the table.)

At these powers, a crankshaft rotation speed is ensured (40 - 50 rpm for carburetor engines and 80 - 120 rpm for diesel engines), which guarantees reliable engine starting.

The step-down transformer was made on a toroidal core taken from the stator of a burnt-out 5 kW asynchronous electric motor. Cross-sectional area of ​​the magnetic circuit S, T = a x b = 20 x 135 = 2700 (mm2) (see Fig. 2)!

A few words about preparing the toroidal core. The stator of the electric motor is freed from winding residues and its teeth are cut out using a sharp chisel and hammer. This is not difficult to do, since the iron is soft, but you need to use safety glasses and gloves.

The material and design of the handle and base of the trigger are not critical, as long as they perform their functions. My handle is made of a steel strip with a cross section of 20x3 mm, with a wooden handle. The strip is wrapped in fiberglass impregnated with epoxy resin. A terminal is mounted on the handle, to which the input of the primary winding and the positive wire of the starting device are then connected.

The frame base is made of a steel rod with a diameter of 7 mm in the form of a truncated pyramid, the ribs of which they are. The device is then attracted to the base by two U-shaped brackets, which are also wrapped in fiberglass impregnated with epoxy resin.

A power switch is attached to one side of the base, and a copper plate of the rectifier unit (two diodes) is attached to the other. A minus terminal is mounted on the plate. At the same time, the plate also serves as a radiator.

The switch is type AE-1031, with built-in thermal protection, rated for a current of 25 A. Diodes are type D161 - D250.

The estimated current density in the windings is 3 - 5 A/mm2. The number of turns per 1 V of operating voltage was calculated using the formula: T = 30/Sct. The number of turns of the primary winding of the transformer was: W1 = 220 x T = 220 x 30/27 = 244; secondary winding: W2 = W3 = 16 x T = 16x30/27 = 18.
The primary winding is made of PETV wire with a diameter of 2.12 mm, the secondary winding is made of an aluminum busbar with a cross-sectional area of ​​36 mm2.

First, the primary winding was wound with a uniform distribution of turns around the entire perimeter. After that, it is turned on through the power cord and the no-load current is measured, which should not exceed 3.5A. It must be remembered that even a slight decrease in the number of turns will lead to a significant increase in the no-load current and, accordingly, to a drop in the power of the transformer and starting device. Increasing the number of turns is also undesirable - it reduces the efficiency of the transformer.

The turns of the secondary winding are also evenly distributed around the entire perimeter of the core. When laying, use a wooden hammer. The leads are then connected to the diodes, and the diodes are connected to the negative terminal on the panel. The middle common terminal of the secondary winding is connected to the “positive” terminal located on the handle.

Now about the wires connecting the starter to the starter. Any carelessness in their manufacture can nullify all efforts. Let's show this with a specific example. Let the resistance Rnp of the entire connecting path from the rectifier to the starter be equal to 0.01 Ohm. Then, at a current I = 250 A, the voltage drop on the wires will be: U pr = I r x Rpr = 250 A x 0.01 Ohm = 2.5 V; in this case, the power loss on the wires will be very significant: P pr = Upr x Iр = 625 W.

As a result, a voltage of not 14, but 11.5 V will be supplied to the starter in operating mode, which, of course, is undesirable. Therefore, the length of the connecting wires should be as short as possible (1_p 100 mm2). The wires must be stranded copper, in rubber insulation. For convenience, the connection to the starter is made quick-release, using pliers or powerful clamps, for example, those used as electrode holders for household welding machines. In order not to confuse the polarity, the handle of the clamps of the positive wire is wrapped with red electrical tape, and the handle of the negative wire is wrapped with black tape.
The short-term operating mode of the starting device (5 - 10 seconds) allows its use in single-phase networks. For more powerful starters (over 2.5 kW), the PU transformer must be three-phase.

A simplified calculation of a three-phase transformer for its manufacture can be made according to the recommendations set out in, or you can use ready-made industrial step-down transformers such as TSPK - 20 A, TMOB - 63, etc., connected to a three-phase network with a voltage of 380 V and producing a secondary voltage of 36 V.

The use of toroidal transformers for single-phase starting devices is not necessary and is dictated only by their best weight and dimensions (weight about 13 kg). At the same time, the technology for manufacturing a starting device based on them is the most labor-intensive.

The calculation of the starting device transformer has some features. For example, the calculation of the number of turns per 1 V of operating voltage, made according to the formula: T = 30/Sct (where Sct is the cross-sectional area of ​​the magnetic circuit), is explained by the desire to “squeeze” the maximum possible out of the magnetic circuit to the detriment of efficiency. This is justified by its short-term (5 - 10 seconds) operating mode. If dimensions do not play a decisive role, you can use a more gentle mode by calculating using the formula: T = 35/Sct. The magnetic core is then taken with a cross-section that is 25 - 30% larger.
The power that can be “removed” from the manufactured PU is approximately equal to the power of the three-phase asynchronous electric motor from which the transformer core is made.

When using a powerful starting device in a stationary version, according to safety requirements, it must be grounded. The handles of the connecting pliers must be rubber insulated. To avoid confusion, it is advisable to mark the “plus” part, for example, with red electrical tape.

When starting, the battery does not need to be disconnected from the starter. In this case, the clamps are connected to the corresponding terminals of the battery. To avoid overcharging the battery, the starting device is immediately turned off after starting the engine.

Today the topic of our post is called a small homemade starting device for starting a car, namely a starting device, not a charger, since we have many articles on this site about car chargers and how to charge. Therefore, today we are exclusively talking about a homemade battery starter.

DIY portable vehicle jump starters

So, what is a starting device for a car in general, in our case for the Hyundai Santa Fe, but this is not particularly important for which car, the capacity of the battery through which this starting device will start the engine is more important.

DIY car starter diagram

In this article we will look at the simplest diagram of a starting device for a car with our own hands, because most people do not have the knowledge in circuit design and electronics to create complex starting devices, and it is not always profitable to purchase a lot of parts for homemade products, which can sometimes come out as budget ready-made starting device for a car from the store.

So, in our case, for the launcher, we do not intend to purchase an expensive high-capacity portable battery, otherwise the device will immediately turn from a budget device into a very expensive one.

We will be making a starting device for a car from a 220V network, for this we will need a powerful transformer, preferably with a power of at least 500 Watt, and preferably 800 Watt, ideally 1.2-1.4 kilowatts = 1400 Watts. Since when starting the engine, the first impulse given by the battery to crank the crankshaft = 200 Amperes and the consumption of the starter is approximately 100 Amperes, and when our 100A device is combined with the battery, they will just give out 200A at the start and then our starter will help maintain the current strength of 100 Amps for normal starting and operation starter until the engine starts completely.

This is what a DIY car starter diagram looks like, photo below

Transformer for car starter

To create such a starting device from a transformer-type network, you need to rewind the transformer itself.

We will need:

• Transformer core
  
• Copper wire 1.5mm-2mm
• Copper wire 10mm
• Two powerful diodes like on welding machines
  
• Alligator clips for ease of use and connecting the starter wires to the car battery, very preferably copper, as they have high conductivity, and thick, at least 2 mm thick
  

We actually begin the process of making a portable starting device for a car with our own hands

To do this, you need to make the primary winding of the transformer with copper wire in insulation with a diameter of at least 1.5-2 mm, the number of turns will be approximately 260-300.

After you wind this wire onto the transformer core, you need to measure the current and voltage produced at the output of these windings, it should be in the range of 220-400 mA.

If you get less, then unwind a few turns of the winding, and if you get more, then on the contrary, wind it up.

Now you need to wind the secondary winding of the transformer of the starting charger. It is advisable to wind it with a multi-core cable with a thickness of at least 10mm, as a rule, the secondary winding contains 13-15 turns, at the output when measuring on the secondary winding you should get 13-14 volts, and as you understand, the voltage has become small, 13 volts in total, but the power the current flowing through it increased to approximately 100 Amperes, but was only 220-400 milliamps, that is, the current increased by approximately 300-400 times, and the voltage decreased by approximately 15 times.

For a battery, both are important, but in this case the key role is played by the current strength.

Winding explanations

If you cannot achieve a voltage of 13-14 volts, then simply wind 10 turns on the secondary winding, measure the voltage, now divide this voltage by the number of turns in our case 10 and get the voltage of one turn, and then simply multiply how many turns are needed to achieve 13-14 volts at the output of the secondary winding of a transformer homemade starting device.

For clarity, let's look at an example:

WE wound the secondary winding with 10 turns, we measure the voltage with a multimeter, for example, we got 20 volts, but we need about 13.

This means that we take our voltage of 20 volts and divide by the number of wound turns 10 = 20/10 = 2, the number 2 is 2 volts and gives us the voltage of one turn, which means how can we achieve 13-14 volts knowing that one turn produced 2 volts.

We take the value of the voltage we need, let it be 14 volts, and divide it by the voltage of one turn 2 volts, = 14/2 = 7, the number 7 is the number of turns on the secondary winding of the car charger necessary to achieve 14 volts of output voltage.

Now let's all wind our 7 turns. And to the outputs of these turns, according to the diagram of the starting device for a car with your own hands, which is located above, we connect our diodes, some car enthusiasts also use a circuit with one diode and one 12V 60-100 watt lamp, as in the photo below

How to start a car using a homemade jump starter

You put the terminals of our homemade starting device on top of the battery terminals, the battery is also connected to the car, we turn on our starter and immediately try to start the engine, as soon as the engine starts, we immediately disconnect the starting device from the network and disconnect it from the battery.

Capacitor jump starter for car

Some car owners, having at their disposal high-power capacitors or, more correctly, capacitors, make a capacitor starting device for the car with their own hands, using them instead of a portable portable battery. That is, such a device can be quickly charged from the mains in a minute, then brought to the car, and the engine can be started without connecting the starter to the mains.

But as a rule, such a scheme requires some deep knowledge of electronics and an understanding of the capacitance of capacitors and the principle of their operation, and even if you don’t have capacitors lying around, then it will not be advisable to buy them, since large capacitors are very expensive, and you will need several of them or even a dozen, and how then the price will not be lower than a good factory-made starting device, while you will also spend a lot of nerves and time creating such a blow.

By the way, the capacitor starting device for the Golden Eagle car has gained some popularity in our area - here is its photo below

Therefore, it was the transformer starter that was most widespread in Soviet times, and even now; store-bought versions of such starters, of course, have been modified and contain various additional elements that make starting the engine from the mains easier and safer.

Any start from any type of launcher always has a negative effect on the condition of the battery, since the battery receives a large current in a very short period of time, which gradually leads to degradation and destruction of its plates during a system start from the launcher.

Therefore, it is better to still use a charger if you are not urgent to start the engine right now.

Well, our post entitled homemade portable launcher for cars is coming to an end. Write your reviews about what you think about this startup device circuit, whether you have ever used it and whether you were able to start the engine of your car.

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