AC vs DC Power (Read This First)

AC vs DC Power (Read This First)

There are two types of electrical power, which are (AC and DC power ) alternating current (AC) and direct current (DC). Either type of current is essential for the functioning of electronics.

Due to these two types of currents, the power associated with them also comes in two different types.

Let’s discuss both different types of power to know about the differences between AC and DC power.

AC Power

The power that comes out of outlets which are defined as periodically changing flow of charge is known as the ac power. Alternating current (AC) power is the standard electricity.

It is produced as the result of the flow of electrical charges such that electrons. The charge can move in either a positive (upward) or in a negative i.e. downward direction.

This process is called the sinusoidal AC wave. These waves are produced when AC power is produced in the plants by alternators.

When the alternators spin a wire loop inside the magnetic field AC power is produced.

By the motion of the wire into the areas of different magnetic polarity the waves are produced.

It is because the current changes the direction when the magnetic field changes due to the spinning motion of the loop of the wire.

When the wire rotates it goes from one magnetic field into the other magnetic field. When we compare the AC vs DC power it can be seen that this wave-like motion of AC power can travel more distance than DC power.

Due to the wave-like motion which can travel long distances as compared to DC power, AC power has a huge amount of uses and advantages when it is delivered to the consumers.

What is the most common source of AC power?

The most common source of AC power is a generator. Mainly a generator has a rotor and a stator. The rotor in the generator produces a moving magnetic field around the stator. It results in the induction of the voltage difference between the windings of the stator and thus produces the alternating current as an output of the generator.

DC power

DC current
DC current

As shown by the name the power produced with the direct current (DC) is called DC power.

DC power can be formed by various sources. The most commonly used sources are solar cells, batteries, fuel cells, and some alternators which are modified.

AC power is also a source of dc power. AC power can be converted into DC power by using a device called a rectifier. The rectifier is the device that converts the AC into DC often built into the power supply of electronic devices.

DC power is more consistent than AC power in the supply of voltage. Due to this reason, a large number of electronics rely on them. Batteries are a common example of DC power using electronics.

Examples of AC and DC sources

The unidirectional flow of electric charge is called direct current (DC). Direct Current does not change direction with time. Examples of DC sources include but are not limited to solar panels, fuel cells, wind turbines, energy from bacteria, dynamos, batteries, button cells, torch cells, thermocouples, and DC generators.

Unlike DC, in Alternating current electric charge changes direction periodically and voltage in AC circuits periodically reverses because current changes direction with time. Examples of Alternating Current (AC) sources include but are not limited to generators, Alternators, inverters, crystal oscillators, AC motors, and LC oscillators.

Do the solar panels generate AC or DC power?

Solar panels generate DC.  We use this DC power as it is and operates DC loads, or we can use it with an inverter to operate AC loads and home appliances.

The power produced by solar panels is stored in batteries for night use. The solar panel is an amazing source of electricity as it produces it from sunlight. When the sunlight reaches the solar panel, energy from the sunlight is absorbed by the Photo Voltaic cell in the solar panel.

This energy produces electric charges that move due to the internal electric field in the cell and in this way electricity flows.

Which power supply is better, AC or DC?

It’s very hard to say that one power supply is better than the other. Both have merits and demerits and they should be chosen according to the requirement.

DC power supply can store the electricity, there is no reactive power, and no advance or delay in the circuit. As far as disadvantages are concerned, there is a strong electrolyte effect, it’s difficult to convert the voltage, and current interruption is quite difficult.

AC power supply has many advantages including but not limited to transformation is easy, the shutdown is quite easy during the flow of power, less power loss due to high voltage transmission, and no issue with positive and negative voltage.

Disadvantages of DC power supply include but are not limited to not being good for long-distance transmission, it is affected by the coils and capacitors, and it requires a high voltage than the targeted voltage.

Why AC power is used more than DC power?

There are some technical and economical reasons behind more use of Alternating Current (AC) than Direct Current(DC). Alternating current can be generated at high voltages, Direct current is the opposite of AC in terms of generation at high voltages because DC produces sparks at the commutator, especially at high voltage. This spark is enough for the commutator to get damaged.

AC power generation is quite cheaper than DC power generation, also AC generation is quite easy than DC generation. High voltage AC generators are much cheaper than the DC generators having the same rating. Transmission of electricity over long distances is quite easy in AC than in DC.

AC generators have quite higher efficiencies than DC ones. The loss of energy during transmission is negligible pretty much less than the DC. AC voltage has the advantage over DC Voltage of stepping up and stepping down as per the requirement.

It does not mean that DC power has no advantages, in fact, DC power has a lot of merits but because AC power generation is cost-effective, it is the main reason for its excessive use around the globe.

Uses of AC and DC Power

DC power is commonly used where the need of storing the current arises. All types of a daily used electrical device such as laptops, mobile phones, torches, etc, and all the other things using battery power, depends on DC power. When these batteries are charged the AC power is converted into DC power and then stored in the batteries. While AC power is commonly used to run almost all home appliances large industries and commercial applications.

As the DC current is smooth therefore many electrical devices use the DC current. One of the main reasons for their large amount of use is that it contains an even voltage. On the other hand, AC power is also very useful in everyday life. Both have their special roles in life. We can say that one is not better than the other

 While looking at the market level of AC and DC we shall see that AC power dominates the market. All the power coming from the outlets into the buildings is in the form of AC.

Even where the power needs to be converted into DC the AC is coming as the source. This is due to the long-distance traveling ability of AC which is not present in DC.

Therefore the AC has traveled long distances to the place where any type of power is needed after that it is converted according to the needs.

AC power is very easy to produce as compared to DC power because of the working process of the generator turn. Moreover, the production of AC is cheaper than DC.

Advantages of AC Power

There are some extra advantages of the AC power in addition to the above mentioned. Here is a list of a few advantages of the AC current

  • It is very easy to change the voltages of the AC power. It can be done by using the transformers.
  • The AC power transferred at the higher voltage does not lose in any reasonable amount.
  • As we know the fact that the power transmitted is directly proportional to the voltage level, at a constant current. Therefore by increasing the voltage large amount of power is transmitted while the current remains constant.
  • AC power transmission is a very cost-efficient manner because with a low amount of current rates of losses are also low as well as large amounts of energy are transmitted by increasing voltages.

DC’s current advantages and disadvantages

There are also some extra features of DC in addition to the above mentioned because DC is not playing less role in the electronics.

  • DC power is used in special applications. The DC power is used whenever the AC supply is not practically possible at long distances.
  • These days all heavy motors are using DC power to make smooth and hard work. A common example is the motors used in heavy-duty machines are the DC motors.
  • In the sub-sea transmission lines, the AC power is converted into DC power and then transmitted by sub-sea transmission lines. After transmission, it is again converted into AC power and given to the customers for use.

AC Vs DC power

We can compare AC Vs DC power in different terms like Direction, the flow of electrons, power factor, etc.

  • The flow of the current direction

AC changes its direction i.e. it flows in both directions i.e. forward and reverses. While DC can flow in one direction in a circuit. And cannot change its direction.

AC current
AC current
  • Frequency

AC power has a frequency of either 50 or 60 Hertz. While the frequency of DC is always Zero. DC doesn’t change its direction or magnitude so it has no frequency.

  • Current magnitude

The magnitude of AC changes continuously while the magnitude of DC is constant. For Pulsating type DC, the magnitude of the current varies only.

  • Power Factor

Another comparison of AC vs DC is the Power factor. The power factor of AC is a value between 0 and 1. While for DC the PF is always unity. SO PF correction, apparent power, reactive power, and active power are only in AC power systems.

  • Types of wave shape

The types of AC are Sinusoidal, Square, Triangular, and Trapezoidal, while DC types are Pure DC and Pulsating DC.

  • Passive Parameter

AC power system has resistance combination of impedance and Reactance while Dc has resistance only.

  • Conversion

We can convert DC into AC using an inverter while converting AC to DC by using a rectifier circuit.

  • Generation Sources

  • AC can be produced using AC generators and can’t be stored in batteries for later usage, while DC can be produced using DC generators and stored in batteries.
  • AC power plants are widely used in AC power generation. While Solar cell plants produce DC power.
  • Applications

Although most electronic application work on DC power, AC power is important as well. The application of AC power is household and industrial loads. While DC is commonly used in electronic devices like Cell phones, Flashlight Electric Vehicles, etc.

If you ask which one is better AC vs DC power? Then the answer is that both are important and has its important applications.

Many applications which need DC power get AC power and convert it to DC voltage for their needs. All electronic devices around you have an internal AC-to-DC converter circuit to feed them with DC voltage instead of AC one.

Which consumes more power, AC or DC?

AC consumes more power than DC. Due to the presence of the reactive components in the AC, power consumption in the AC circuit is of a higher value. That is the reason in DC Circuits heat dissipation(loss) is minimum as compared to AC circuits.

DC fan is one of the prominent fans as far as less power consumption is concerned than AC fans. DC fans consume 70% less power to produce the same output as AC fans.

Which one is a more economical power system?

AC power system is more economical than the DC power system. For transmitting voltage over longer distances, voltages must be stepped up and down and for this transformers are required, this is easy and economical with the AC.

While the cost for boosters and converters for DC is much more than the transformers in the AC. Rectification cost would be very great if we use DC for a longer distance.

As mostly electricity generating stations are usually very far away from the cities due to multiple reasons like safety, convenience, and availability of the raw material, so from those stations electricity has to be transmitted to the cities.

When power is transferred through conductors from thousands of kilometers, obviously system efficiency will be reduced due to the multiples losses like copper losses, stray losses, etc. To overcome these losses effect, we have to increase the voltage level for the transmission and at the receiving end, we have to lower the voltage level to make it practical.

Here the choice of AC or DC will surely depend on the cost of equipment which will increase or decrease the voltage level. Transformers and related equipment which serve this purpose are far cheaper than the boosters and converters used in DC.

Why 60Hz frequency is used in the USA?

The reason why 60hz frequency is used in America is more connected with historical facts than technical reasons. Companies in the USA manufacture 60hz equipment and companies in Europe and all over the world manufacture 50hz equipment because they have a monopoly.

Also, it depends upon the starting time of the electrification of a country, because if you change the frequency from 60hz to 50hz or 50 to 60hz, you have to change many things, so it’s all about history.

Advantages and disadvantages of using 60hz frequency

A higher frequency of 60hz has both advantages and disadvantages. Advantages include a reduction in the size of the transformers, less flicker in the lamps, not much fluctuation in the single phase machines, and a higher speed in the synchronous motors.

Disadvantages of using 60hz include an increase in the line drop, less transmission line capacity, and more transmission losses.

Can we control the frequency of the AC power?

Yes, the frequency of the AC power can be controlled. Frequency is controlled by the filter circuits, Low-pass, high-pass, and band-pass filters are used to serve this purpose. By using these methods bandwidth of the signal is increased or decreased to decrease or increase the frequency respectively.

For example in the induction machines like the induction motors or the alternator, the frequency changes and we control its speed with the frequency control mechanism.

How do I know if my appliances are AC or DC?

One way to determine whether an appliance is AC or DC is to check its nameplate, usually, you will find the input and output. The AC voltage will be 110 or 220 V for single-phase devices, and 380 0r 460 V for three-phase loads.

While DC voltage will be almost 6, 12, or 24 VDC. But make sure the voltage is the input voltage of the device not only the charging or the output voltage.

Generally, devices that consist of batteries run on DC. Generally, the devices which consist of the motors run on AC.

Appliances like bulbs, motors, refrigerators, geysers, and grinders run on the AC. Devices like phone chargers, LED lights, and laptops use DC for their operation.

Take into a confederation that devices with batteries use an AC source to charge the batteries. Then, the internal DC circuit feeds the device from the battery.

What devices use DC power?

The list of devices that use direct current is infinite.

  • Cell phones
  • Flashlights
  • TV remotes
  • Electric vehicles
  • Flat screens TVs (actually AC is the input power, but it is converted into DC)
  • Hybrid vehicles
  • Computers
  • Portable Power hand tools
  • Drones, and in general anything that is powered by batteries.

DO mobile chargers have AC or DC power supply?

A mobile charger is a DC power supply. AC supply is given to the mobile charger as input and this steps down to the voltage (5/9/12 DC Volt) depending upon the rating of the charger using a small transformer or DC circuit. Mobile chargers convert AC to DC.

Then, this output passed through the rectifier chip to get the usable (5/9/12 Volt), and after this capacitor filters out the ripples from the rectified output. Then voltage regulator regulates the voltage to keep it constant.

All batteries are DC so, it’s fair to say that a mobile charger is a power converter from AC to DC power, to feed the mobile battery.

Is a battery charger AC or DC?

The battery charger receives AC as input and the rectifier converts AC into DC and gives it to the battery. All batteries are DC sources, this means battery charger output should be DC to charge batteries. The input of the charger is the AC power. An electronic circuit converts AC to DC power for this purpose.

The performance of a battery mainly depends on its use and how carefully they are charged with the battery charger. Therefore it is very crucial to invest in selecting a good battery charger. A good charger DC output should have no AC noise. The output DC is filtered before charging the battery.

A battery charger gives the battery the required power DC power to continuously operate by forcing an electric current through it. The battery charger is a special power supply having a current-limiting ability and with this ability, it avoids the overcharging of the battery.

A battery works by converting chemical energy into electrical DC energy and once the electrolyte of the battery is used up, it needs to be recharged. A battery charger provides direct current(DC) to the battery to restore used-up electrolytes.

Can LED TV run on DC Power?

YES, LED TV can run on DC power. In fact, it cannot run on AC directly as it will burn out all the internal circuitry of the LED TV because the power circuitry inside the LED TVs supports DC.

For operating LED TVs on AC, we use an internal power adapter circuit to convert AC power into DC power and feed the TV circuit components.

There is usually some inverter or AC/DC converter via a rectifier bridge system in the adapter to change AC into DC and power up the LED TV.

But if the real question is about whether can you operate LED TV directly to a DC power supply, like a battery, then the answer is no you can’t operate TV directly on a DC battery or power supply. This is clear because all modern TVs are designed to run on a direct AC power supply and it has an internal circuit to convert the AC into DC power.

However, you can use an inverter to convert DC power into AC and then feed the TV. This way is suitable if you have a TV in your home truck or in a camping night. Make sure the inverter is suitable to operate the TV. Check its power and voltage, input and output.

Why does the AC power need a neutral?

The neutral wire is used in the Alternating Current (AC) because it provides the circulation and return path of the current flows back to the source from the load. It is actually used to complete the flow of electricity in a circuit.

Mostly it is considered to be the zero voltage but in the case of a non-linear electrical system this could vary and that’s why it is connected to the ground. For this reason, the neutral wire is usually smaller in size than the hot wires in large industrial loads.

Like any other component of an electrical system, the neutral wire is also an essential part to create a functional electrical system.

Without the neutral wire, there would be no circuit for electricity to flow along and complete its rotation back to the power source.

Can I connect DC power supplies in parallel?

In general, YES you can connect two DC power supplies in parallel. The performance of the supplies largely depends upon the good match in their voltages. If one’s voltage is higher than the other then the higher one will supply most of the current and the lower one will be idle.

Mainly this parallel idea depends upon the supply regulation and current limiting ability. Even if one supply is 5.001 V and the other one is 4.99 then the larger voltage supply will carry all the current, so it may or may not be a good idea to parallel two supplies.

Is it normal for a power supply and charger to get hot?

Yes, it is normal for power supplies and chargers to get hot. Actually, the conversion from AC to DC is not 100% efficient.

Some percentage of power like 3 to 7% is dissipated in the form of heat. Usually, chargers are not designed to optimize heat dissipation, so we get the hot chargers as a result.

Usually, there is a plastic casing on the circuit board in the chargers and there is no ventilation thus it gets hot even when the workload is not too much high.

But never overload a power supply, this may increase its temperature to a dangerous degree. A well-protected power supply should trip a CB or blow a fuse in case of overload.