How to increase the strength of electric current. Conductor resistance

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Probably, the problem we’ll talk about today is familiar to many. I think everyone has had the need to increase the output current of the power supply. Let's look at a specific example, you have a 19-volt power adapter from a laptop, which provides an output current of, well, let's say, around 5A, and you need a 12-volt power supply with a current of 8-10A. So the author (YouTube channel “AKA KASYAN”) once needed a power supply with a voltage of 5V and a current of 20A, and at hand was a 12-volt power supply for LED strips with an output current of 10A. And so the author decided to remake it.

Yes, it’s certainly possible to assemble the required power source from scratch or use the 5-volt bus of any cheap computer power supply, but it will be useful for many DIY electronics engineers to know how to increase the output current (or in common parlance, the amperage) of almost any switching power supply.

As a rule, power supplies for laptops, printers, all kinds of monitor power adapters, and so on, are made according to single-ended circuits; most often they are flyback and the construction is no different from each other. There may be a different configuration, a different PWM controller, but the circuit diagram is the same.

A single-cycle PWM controller is most often from the UC38 family, a high-voltage field-effect transistor that pumps a transformer, and at the output a half-wave rectifier in the form of a single or dual Schottky diode.

After that there is a choke, storage capacitors, and a voltage feedback system.

Thanks to feedback, the output voltage is stabilized and strictly kept within the specified limit. Feedback is usually built on the basis of an optocoupler and a reference voltage source tl431.

Changing the resistance of the divider resistors in its wiring leads to a change in the output voltage.

This was a general introduction, and now about what we have to do. It should be noted right away that we are not increasing the power. This power supply has an output power of about 120W.

We are going to reduce the output voltage to 5V, but in return we will increase the output current by 2 times. We multiply the voltage (5V) by the current (20A) and in the end we get a calculated power of about 100W. We will not touch the input (high-voltage) part of the power supply. All alterations will affect only the output part and the transformer itself.

But later, after checking, it turned out that the original capacitors are also quite good and have a fairly low internal resistance. Therefore, in the end the author soldered them back.

Next, we unsolder the inductor and the pulse transformer.

The diode rectifier is quite good - 20 ampere. The best thing is that the board has a seat for a second diode of the same type.

As a result, the author did not find a second such diode, but since he recently received exactly the same diodes from China only in a slightly different package, he plugged a couple of them into the board, added a jumper and strengthened the tracks.

As a result, we get a 40A rectifier, that is, with a double current reserve. The author installed diodes at 200V, but this makes no sense, he just has a lot of them.

You can install regular Schottky diode assemblies from a computer power supply with a reverse voltage of 30-45V or less.
We're done with the rectifier, let's move on. The choke is wound with this wire.

We throw it away and take this wire.

We wind about 5 turns. You can use a native ferrite rod, but the author had a thicker one lying around nearby, on which the turns were wound. True, the rod turned out to be slightly long, but later we will break off all the excess.

The transformer is the most important and responsible part. Remove the tape, heat the core with a soldering iron on all sides for 15-20 minutes to loosen the glue, and carefully remove the core halves.

Leave the whole thing for ten minutes to cool. Next, remove the yellow tape and unwind the first winding, remembering the direction of winding (or just take a couple of photos before disassembling, in which case they will help you). Leave the other end of the wire on the pin. Next, unwind the second winding. Also, we do not solder the second end.

After this, we have before us the secondary (or power) winding of our own person, which is exactly what we were looking for. This winding is completely removed.

It consists of 4 turns, wound with a bundle of 8 wires, each with a diameter of 0.55 mm.

The new secondary winding we will wind contains only one and a half turns, since we only need 5V of output voltage. We will wind it in the same way, we will take a wire with a diameter of 0.35 mm, but the number of cores is already 40 pieces.

This is much more than is needed, but, however, you can compare it yourself with the factory winding. Now we wind all the windings in the same order. Be sure to follow the winding direction of all windings, otherwise nothing will work.

It is advisable to tin the cores of the secondary winding before winding begins. For convenience, we divide each end of the winding into 2 groups so as not to drill giant holes on the board for installation.

After the transformer is installed, we find the tl431 chip. As mentioned earlier, it is this that sets the output voltage.

We find a divider in its harness. In this case, 1 of the resistors of this divider is a pair of smd resistors connected in series.

The second divider resistor is located closer to the output. In this case, its resistance is 20 kOhm.

We unsolder this resistor and replace it with a 10 kOhm trimmer.

We connect the power supply to the network (necessarily through a safety incandescent network lamp with a power of 40-60W). We connect a multimeter and preferably a small load to the output of the power supply. In this case, these are low-power 28V incandescent lamps. Then, very carefully, without touching the board, we rotate the trimming resistor until the desired output voltage is obtained.

Next, we turn everything off and wait 5 minutes so that the high-voltage capacitor on the unit is completely discharged. Then we unsolder the trimming resistor and measure its resistance. Then we replace it with a permanent one, or leave it. In this case, we will also have the ability to adjust the output.

The article will talk about how to increase the current in the charger circuit, in the power supply, transformer, in the generator, in the USB ports of the computer without changing the voltage.

What is current strength?

Electric current is the ordered movement of charged particles inside a conductor with the obligatory presence of a closed circuit.

The appearance of current is due to the movement of electrons and free ions that have a positive charge.

As they move, charged particles can heat the conductor and have a chemical effect on its composition. In addition, the current can influence neighboring currents and magnetized bodies.

Current strength is an electrical parameter that is a scalar quantity. Formula:

I=q/t, where I is current, t is time, and q is charge.

It is also worth knowing Ohm's law, according to which current is directly proportional to U (voltage) and inversely proportional to R (resistance).

Current strength is of two types - positive and negative.

Below we will consider what this parameter depends on, how to increase the current strength in the circuit, in the generator, in the power supply and in the transformer.

What does current strength depend on?

To increase I in a circuit, it is important to understand what factors can influence this parameter. Here we can highlight the dependence on:

Resistance. The smaller the parameter R (Ohm), the higher the current in the circuit.
Voltages. Using the same Ohm's law, we can conclude that as U increases, the current strength also increases.
Magnetic field strength. The larger it is, the higher the voltage.
Number of coil turns. The greater this indicator, the greater U and, accordingly, the higher I.
The power of the force that is transmitted to the rotor.
Diameter of conductors. The smaller it is, the higher the risk of heating and burning out the supply wire.
Power supply designs.
The diameter of the stator and armature wires, the number of ampere-turns.
Generator parameters - operating current, voltage, frequency and speed.

How to increase the current in a circuit?

There are situations when it is necessary to increase I, which flows in the circuit, but it is important to understand that measures need to be taken; this can be done using special devices.

Let's look at how to increase the current using simple devices.

To complete the work you will need an ammeter.

Option 1.

According to Ohm's law, current is equal to voltage (U) divided by resistance (R). The simplest way to increase force I, which suggests itself, is to increase the voltage that is supplied to the input of the circuit, or to reduce the resistance. In this case, I will increase in direct proportion to U.

For example, when connecting a 20 Ohm circuit to a power source with U = 3 Volts, the current value will be 0.15 A.

If you add another 3V power source to the circuit, the total value of U can be increased to 6 Volts. Accordingly, the current will also double and reach a limit of 0.3 Amperes.

The power supplies must be connected in series, that is, the plus of one element is connected to the minus of the first.

To obtain the required voltage, it is enough to connect several power sources into one group.

In everyday life, sources of constant U, combined into one group, are called batteries.

Despite the obviousness of the formula, practical results may differ from theoretical calculations, which is due to additional factors - heating of the conductor, its cross-section, the material used, and so on.

As a result, R changes towards an increase, which leads to a decrease in force I.

Increasing the load in the electrical circuit can cause overheating of the conductors, burnout, or even a fire.

That is why it is important to be careful when operating devices and take into account their power when choosing a cross-section.

The value of I can be increased in another way by reducing the resistance. For example, if the input voltage is 3 Volts and R is 30 Ohms, then a current of 0.1 Ampere passes through the circuit.

If you reduce the resistance to 15 Ohms, the current strength, on the contrary, will double and reach 0.2 Amperes. The load is reduced to almost zero during a short circuit near the power source, in this case I increases to the maximum possible value (taking into account the power of the product).

Resistance can be further reduced by cooling the wire. This effect of superconductivity has long been known and is actively used in practice.

To increase the current in a circuit, electronic devices are often used, for example, current transformers (as in welders). The strength of variable I in this case increases with decreasing frequency.

If there is active resistance in the AC circuit, I increases as the capacitance of the capacitor increases and the inductance of the coil decreases.

In a situation where the load is purely capacitive in nature, the current increases with increasing frequency. If the circuit includes inductors, the force I will increase simultaneously with the decrease in frequency.

Option 2.

To increase the current strength, you can focus on another formula, which looks like this:

I = U*S/(ρ*l). Here we only know three parameters:

S - wire cross-section;
l is its length;
ρ is the electrical resistivity of the conductor.

To increase the current, assemble a chain containing a current source, a consumer and wires.

The role of the current source will be performed by a rectifier, which allows you to regulate the EMF.

Connect the chain to the source, and the tester to the consumer (pre-set the device to measure current). Increase the EMF and monitor the indicators on the device.

As noted above, as U increases, it is possible to increase the current. A similar experiment can be done for resistance.

To do this, find out what material the wires are made of and install products that have lower resistivity. If you cannot find other conductors, shorten the ones already installed.

Another way is to increase the cross-section, for which it is worth mounting similar conductors parallel to the installed wires. In this case, the cross-sectional area of the wire increases and the current increases.

If we shorten the conductors, the parameter we are interested in (I) will increase. If desired, options for increasing the current can be combined. For example, if the conductors in the circuit are shortened by 50% and U is raised by 300%, then the force I will increase 9 times.

How to increase the current in the power supply?

On the Internet you can often come across the question of how to increase I in the power supply without changing the voltage. Let's look at the main options.

Situation No. 1.

A 12 Volt power supply operates with a current of 0.5 Amperes. How to raise I to its maximum value? To do this, a transistor is placed in parallel with the power supply. In addition, a resistor and stabilizer are installed at the input.

When the voltage across the resistance drops to the required value, the transistor opens, and the rest of the current flows not through the stabilizer, but through the transistor.

The latter, by the way, must be selected according to the rated current and a radiator installed.

In addition, the following options are possible:

Increase the power of all elements of the device. Install a stabilizer, a diode bridge and a higher power transformer.
If there is current protection, reduce the value of the resistor in the control circuit.

Situation No. 2.

There is a power supply for U = 220-240 Volts (at the input), and at the output a constant U = 12 Volts and I = 5 Amperes. The task is to increase the current to 10 Amps. In this case, the power supply should remain approximately the same dimensions and not overheat.

Here, to increase the output power, it is necessary to use another transformer, which is converted to 12 Volts and 10 Amps. Otherwise, the product will have to be rewound yourself.

In the absence of the necessary experience, it is better not to take risks, because there is a high probability of a short circuit or burnout of expensive circuit elements.

The transformer will have to be replaced with a larger product, and the damper chain located on the DRAIN of the key will also have to be recalculated.

The next point is replacing the electrolytic capacitor, because when choosing a capacitance you need to focus on the power of the device. So, for 1 W of power there are 1-2 microfarads.

After such a modification, the device will heat up more, so installing a fan is not necessary.

How to increase the current in the charger?

When using chargers, you may notice that chargers for a tablet, phone or laptop have a number of differences. In addition, the speed at which devices are charged may also vary.

Here a lot depends on whether an original or non-original device is used.

To measure the current that goes to your tablet or phone from the charger, you can use not only an ammeter, but also the Ampere app.

Using the software, it is possible to determine the charging and discharging speed of the battery, as well as its condition. The application is free to use. The only drawback is advertising (the paid version does not have it).

The main problem with charging batteries is the low current of the charger, which is why the time to gain capacity is too long. In practice, the current flowing in the circuit directly depends on the power of the charger, as well as other parameters - cable length, thickness and resistance.

Using the Ampere application, you can see at what current the device is charged, and also check whether the product can charge at a higher speed.

To use the capabilities of the application, just download it, install and run it.

After this, the phone, tablet or other device is connected to the charger. That's all - all that remains is to pay attention to the current and voltage parameters.

In addition, you will have access to information about the battery type, U level, battery condition, as well as temperature conditions. You can also see the maximum and minimum I that occur during the cycle.

If you have several chargers at your disposal, you can run the program and try charging each of them. Based on the test results, it is easier to select a charger that provides the maximum current. The higher this parameter is, the faster the device will charge.

Current measurement isn't the only thing Ampere can do. With its help, you can check how much I is consumed in standby mode or when turning on various games (applications).

For example, after turning off the display brightness, deactivating GPS or data transfer, it is easy to notice a decrease in load. Against this background, it is easier to conclude which options drain the battery the most.

What else is worth noting? All manufacturers recommend charging devices with “native” chargers that produce a certain current.

But during operation, there are situations when you have to charge your phone or tablet with other chargers that have more power. As a result, the charging speed may be higher. But not always.

Few people know, but some manufacturers limit the maximum current that the device’s battery can accept.

For example, a Samsung Galaxy Alpha device comes with a 1.35 Ampere charger.

When connecting a 2-amp charger, nothing changes - the charging speed remains the same. This is due to a limitation set by the manufacturer. A similar test was carried out with a number of other phones, which only confirmed the guess.

Taking into account the above, we can conclude that non-native chargers are unlikely to cause harm to the battery, but can sometimes help with faster charging.

Let's consider another situation. When charging a device via a USB connector, the battery gains capacity more slowly than when charging the device from a conventional charger.

This is due to the limitation of the current that a USB port can supply (no more than 0.5 Ampere for USB 2.0). When using USB3.0, the current increases to 0.9 Ampere.

In addition, there is a special utility that allows the “troika” to pass a larger I through itself.

For devices like Apple the program is called ASUS Ai Charger, and for other devices it is called ASUS USB Charger Plus.

How to increase the current in a transformer?

Another question that worries electronics enthusiasts is how to increase the current strength in relation to a transformer.

Here are the following options:

Install a second transformer;
Increase the diameter of the conductor. The main thing is that the cross-section of the “iron” allows it.
Raise U;
Increase the cross-section of the core;
If the transformer operates through a rectifier device, it is worth using a product with a voltage multiplier. In this case, U increases, and with it the load current also increases;
Buy a new transformer with a suitable current;
Replace the core with a ferromagnetic version of the product (if possible).

A transformer has a pair of windings (primary and secondary). Many output parameters depend on the wire cross-section and the number of turns. For example, there are X turns on the high side and 2X on the other side.

This means that the voltage on the secondary winding will be lower, as will the power. The output parameter also depends on the efficiency of the transformer. If it is less than 100%, U and the current in the secondary circuit decrease.

Taking into account the above, the following conclusions can be drawn:

The power of the transformer depends on the width of the permanent magnet.
To increase the current in the transformer, a decrease in R load is required.
The current (A) depends on the diameter of the winding and the power of the device.
In case of rewinding, it is recommended to use thicker wire. In this case, the wire mass ratio on the primary and secondary windings is approximately identical. If you wind 0.2 kg of iron on the primary winding and 0.5 kg on the secondary winding, the primary will burn out.

How to increase the current in the generator?

The current in the generator directly depends on the load resistance parameter. The lower this parameter, the higher the current.

If I is higher than the nominal parameter, this indicates the presence of an emergency mode - frequency reduction, generator overheating and other problems.

For such cases, protection or disconnection of the device (part of the load) must be provided.

In addition, with increased resistance, the voltage decreases, and U increases at the generator output.

To maintain the parameter at an optimal level, regulation of the excitation current is provided. In this case, an increase in the excitation current leads to an increase in the generator voltage.

The network frequency must be at the same level (constant).

Let's look at an example. In a car generator, it is necessary to increase the current from 80 to 90 Amperes.

To solve this problem, you need to disassemble the generator, separate the winding and solder the lead to it, followed by connecting the diode bridge.

In addition, the diode bridge itself is changed to a part with higher performance.

After this, you need to remove the winding and a piece of insulation in the place where the wire is to be soldered.

If there is a faulty generator, the lead is bitten off from it, after which the legs of the same thickness are built up using copper wire.

Conductor resistance. Resistivity

Ohm's law is the most important in electrical engineering. That is why electricians say: “Whoever does not know Ohm’s Law should sit at home.” According to this law, current is directly proportional to voltage and inversely proportional to resistance (I = U / R), where R is a coefficient that relates voltage and current. The unit of measurement for voltage is Volt, resistance is Ohm, current is Ampere.
To show how Ohm's Law works, let's look at a simple electrical circuit. The circuit is a resistor, which is also a load. A voltmeter is used to record the voltage across it. For load current - ammeter. When the switch is closed, current flows through the load. Let's see how well Ohm's Law is observed. The current in the circuit is equal to: circuit voltage 2 Volts and circuit resistance 2 Ohms (I = 2 V / 2 Ohms = 1 A). The ammeter shows this much. The resistor is a load with a resistance of 2 ohms. When we close switch S1, current flows through the load. Using an ammeter we measure the current in the circuit. Using a voltmeter, measure the voltage at the load terminals. The current in the circuit is equal to: 2 Volts / 2 Ohms = 1 A. As you can see, this is observed.

Now let's figure out what needs to be done to increase the current in the circuit. First, increase the voltage. Let's make the battery not 2 V, but 12 V. The voltmeter will show 12 V. What will the ammeter show? 12 V/ 2 Ohm = 6 A. That is, by increasing the voltage across the load by 6 times, we obtained an increase in current strength by 6 times.

Let's consider another way to increase the current in a circuit. You can reduce the resistance - instead of a 2 Ohm load, take 1 Ohm. What we get: 2 Volts / 1 Ohm = 2 A. That is, by reducing the load resistance by 2 times, we increased the current by 2 times.
In order to easily remember the formula of Ohm's Law, they came up with the Ohm triangle:
How can you determine the current using this triangle? I = U / R. Everything looks quite clear. Using a triangle, you can also write formulas derived from Ohm’s Law: R = U / I; U = I * R. The main thing to remember is that the voltage is at the vertex of the triangle.

In the 18th century, when the law was discovered, atomic physics was in its infancy. Therefore, Georg Ohm believed that the conductor is something similar to a pipe in which liquid flows. Only liquid in the form of electric current.
At the same time, he discovered a pattern that the resistance of a conductor becomes greater as its length increases and less as its diameter increases. Based on this, Georg Ohm derived the formula: R = p * l / S, where p is a certain coefficient multiplied by the length of the conductor and divided by the cross-sectional area. This coefficient was called resistivity, which characterizes the ability to create an obstacle to the flow of electric current, and depends on what material the conductor is made of. Moreover, the greater the resistivity, the greater the resistance of the conductor. To increase the resistance, it is necessary to increase the length of the conductor, or reduce its diameter, or select a material with a higher value of this parameter. Specifically, for copper the resistivity is 0.017 (Ohm * mm2/m).

Conductors

Let's look at what types of conductors there are. Today, the most common conductor is copper. Due to its low resistivity and high resistance to oxidation, with relatively low fragility, this conductor is increasingly being used in electrical applications. Gradually, the copper conductor is replacing the aluminum one. Copper is used in the production of wires (cores in cables) and in the manufacture of electrical products.

The second most commonly used material is aluminum. It is often used in older wiring that is being replaced by copper. Also used in the production of wires and electrical products.
The next material is iron. It has a resistivity much greater than copper and aluminum (6 times more than copper and 4 times more than aluminum). Therefore, as a rule, it is not used in the production of wires. But it is used in the manufacture of shields and tires, which, due to their large cross-section, have low resistance. Just like a fastener.

Gold is not used in electrics, as it is quite expensive. Due to its low resistivity and high oxidation protection, it is used in space technology.

Brass is not used in electrical applications.

Tin and lead are commonly used in alloying as solder. They are not used as conductors for the manufacture of any devices.

Silver is most often used in military equipment for high-frequency devices. Rarely used in electrical applications.

Tungsten is used in incandescent lamps. Due to the fact that it does not collapse at high temperatures, it is used as filaments for lamps.

It is used in heating devices, as it has a high resistivity with a large cross-section. A small amount of its length is needed to make a heating element.

Coal and graphite are used in electric brushes in electric motors.
Conductors are used to pass current through themselves. In this case, the current does useful work.

Dielectrics

Dielectrics have a high resistivity value, which is much higher in comparison with conductors.

Porcelain is used, as a rule, in the manufacture of insulators. Glass is also used to produce insulators.

Ebonite is most often used in transformers. It is used to make the frame of the coils on which the wire is wound.

Also, different types of plastics are often used as dielectrics. Dielectrics include the material from which the insulating tape is made.

The material from which the insulation in the wires is made is also a dielectric.

The main purpose of a dielectric is to protect people from electric shock and to insulate current-carrying conductors among themselves.

According to Ohm's law for direct current electrical circuits: U = IR, where: U is the magnitude of the voltage supplied to the electrical circuit,
R is the total resistance of the electrical circuit,
I is the amount of current flowing through the electrical circuit; to determine the current strength, you need to divide the voltage supplied to the circuit by its total resistance. I=U/RAccordingly, in order to increase the current, you can increase the voltage supplied to the input of the electrical circuit or reduce its resistance. The current will increase if you increase the voltage. The increase in current will be proportional to the increase in voltage. For example, if a circuit with a resistance of 10 Ohms was connected to a standard 1.5 Volt battery, then the current flowing through it was:
1.5/10=0.15 A (Ampere). When another 1.5 V battery is connected to this circuit, the total voltage will become 3 V, and the current flowing through the electrical circuit will increase to 0.3 A.
The connection is made in series. that is, the plus of one battery is added to the minus of the other. Thus, by connecting a sufficient number of power sources in series, you can obtain the required voltage and ensure the flow of current of the required strength. Several voltage sources combined into one circuit are called a battery of elements. In everyday life, such designs are usually called “batteries” (even if the power source consists of only one element). However, in practice, the increase in current strength may differ slightly from the calculated one (proportional to the increase in voltage). This is mainly due to the additional heating of the circuit conductors, which occurs with an increase in the current passing through them. In this case, as a rule, there is an increase in the resistance of the circuit, which leads to a decrease in current strength. In addition, an increase in the load on the electrical circuit can lead to its burnout or even fire. You need to be especially careful when using electrical appliances that can only operate at a fixed voltage.

If you reduce the total resistance of an electrical circuit, the current will also increase. According to Ohm's law, the increase in current will be proportional to the decrease in resistance. For example, if the voltage of the power source was 1.5 V, and the circuit resistance was 10 Ohms, then an electric current of 0.15 A passed through such a circuit. If then the circuit resistance is halved (made equal to 5 Ohms), then the current flowing through the circuit current will double and amount to 0.3 Amperes. An extreme case of a decrease in load resistance is a short circuit, in which the load resistance is practically zero. In this case, of course, infinite current does not arise, since the circuit has internal resistance of the power source. A more significant reduction in resistance can be achieved by greatly cooling the conductor. The production of enormous currents is based on this effect of superconductivity.

All kinds of electronic devices are used to increase the strength of alternating current. mainly current transformers, used, for example, in welding machines. The strength of the alternating current also increases as the frequency decreases (since, due to the surface effect, the active resistance of the circuit decreases). If there are active resistances in the alternating current circuit, the current strength will increase as the capacitance of the capacitors increases and the inductance of the coils (solenoids) decreases. If the circuit contains only capacitors (capacitors), the current will increase as the frequency increases. If the circuit consists of inductors, then the current strength will increase as the frequency of the current decreases.

Instructions

According to Ohm's law for direct current electrical circuits: U = IR, where: U is the value supplied to the electrical circuit,
R is the total resistance of the electrical circuit,
I is the amount of current flowing through an electrical circuit; to determine the current strength, you need to divide the voltage supplied to the circuit by its total resistance. I=U/RAccordingly, in order to increase the current, you can increase the voltage supplied to the input of the electrical circuit or reduce its resistance. The current will increase if you increase the voltage. An increase in current will result in an increase in voltage. For example, if a circuit with a resistance of 10 Ohms was connected to a standard 1.5 Volt battery, then the current flowing through it was:
1.5/10=0.15 A (Ampere). When another 1.5 V battery is connected to this circuit, the total voltage will become 3 V, and the current flowing through the electrical circuit will increase to 0.3 A.
The connection is made “in series,” that is, the plus of one battery is connected to the minus of the other. Thus, by connecting a sufficient number of power sources in series, you can obtain the required voltage and ensure the flow of current of the required strength. Several voltage sources are combined into one circuit by a battery of cells. In everyday life, such designs are usually called “batteries” (even if the power supply consists of only one element). However, in practice, the increase in current strength may differ slightly from the calculated one (proportional to the increase in voltage). This is mainly due to the additional heating of the circuit conductors, which occurs with an increase in the current passing through them. In this case, as a rule, there is an increase in the resistance of the circuit, which leads to a decrease in current strength. In addition, an increase in the load on the electrical circuit can lead to its burnout or even fire. You need to be especially careful when using electrical appliances that can only operate at a fixed voltage.

To increase the power of alternating current, all kinds of electronic devices are used, mainly current transformers, used, for example, in welding machines. The strength of the alternating current also increases as the frequency decreases (since, due to the surface effect, the active resistance of the circuit decreases). If there are active resistances in the alternating current circuit, the current strength will increase as the capacitance of the capacitors increases and the inductance of the coils (solenoids) decreases. If the circuit contains only capacitors (capacitors), the current will increase as the frequency increases. If the circuit consists of inductors, then the current strength will increase as the frequency of the current decreases.