Alternating Current (AC) and direct currents (DC) are the only ways an electric current can flow. But over the years, AC has remained the most dominant way over direct current. This is mainly because of its ability to minimize energy losses by modifying its voltage with ease using a transformer. The fact that it’s also cheaper, easy, and safe for AC to transfer energy makes it outstanding.
However, DC has a role to play in energy transmission when AC cannot be used. It comes a time where each one is needed, and the other can’t be its substitute. Here are the in-depth reasons as to why AC is preferred to DC and its disadvantages. Keep reading!
Summary Table For The Advantages Of AC Over DC
| AC | DC |
| Cheaper to generate | Expensive to generate |
| Small transmission losses | Losses a lot of energy when transmitted over a long distance |
| Low loss of energy during transmission for ac than dc | More insulation is required in the Ac transmission system. |
| It can be converted easily to DC power with the help of rectifiers | It cannot be converted into AC |
| AC can be produced at high voltages | DC cannot be produced at high voltage as this causes sparks at the commutator |
| The current’s magnitude can be reduced by the use of a conductor or an inductance with minimum energy loss | The magnitude cannot be changed |
Difference Detween AC Over DC
Just as its names suggest, in DC, a direct current flows in one direction, i.e., forward through a wire. DC has both plus and minus signs, and it’s either dotted or a straight line. It’s used to charge batteries and supply power to electronic devices, e.g., Flat-screen television, electric vehicles, mobile batteries etc. In short, anything that uses a battery, USB cables and an AC adapter while plugging into the socket for power depends on DC.
AC, on the other hand, keeps on changing direction periodically, i.e., forward and backward. It alternates the order between 50 to 60 times per second depending on the country’s electric system. Globally, AC is the standard electric power preferred for household equipment and offices. You can identify them in a waveform known as a sine wave or merely a curved line. It can power electric motors typically used on a washing machine, dishwasher and refrigerators, among others.
What Are The Advantages Of AC Over DC?
AC is the most preferred method of transmitting power due to the following advantages over AC:
1. There is minimum loss of energy during transmission in AC as compared to the DC.
2. With the help of rectifiers, AC can be converted easily into DC.
3. High-speed AC motors have low maintenance cost with high efficiency.
4. The supply we all majorly got in our homes is transmitted AC over long distances with step-up transformers, which is impossible for DC.
5. It is less costly to generate AC compared to DC.
6. With AC, there is ease variation that can be done using transformers by either step-up/down.
7. AC is supplied under high voltages with small transmission losses than DC transmission.
8. When it comes to AC generators, their efficiency is higher than DC types.
9. AC power allows for the use of an indicator and capacitor in an electronic circuit.
What Are The Disadvantages Of AC Over DC?
AC is the best choice does not mean it has it all. This type of current has some disadvantages highlighted below:
1. As much as AC is much preferred than DC in most cases, there are instances where only DC voltages can be used, such as electroplating, charging batteries, and electric traction.
2. AC is more dangerous to work with as compared to DC when the voltages are high.
3. More insulation is required in the AC transmission system.
4. AC is more dangerous compared with DC.
Which Is More Dangerous, AC Or DC?
It is believed that the AC is usually five times more harmful than the DC. The high frequency of AC is the primary reason for the severe effects on human bodies. It has sixty circles of frequency, which is incredibly damaging. Note that even a small frequency of about twenty-five volts voltage can kill you. This shows how dangerous AC can be if not handle with a lot of care.
AC causes hard contraction of the muscles and sweating, which reduces skin resistance. If you are in a situation where a person is directly exposed to AC, it is advisable to free them from the contact as soon as possible to avoid significant injuries or death. Simply because the longer contact victim has with the AC voltage, the further skin resistance reduces, causing death
What Is DC Used For?
DC is suitable for electronic devices with the battery as a power source because it charges them. For instance, rechargeable electronic devices like cellphones use USB cables, whereas laptops have an AC adapter that converts AC to DC.
Changing DC voltage is costly and complicated than ACs, making it a poor choice when transmitting high electricity voltage. However, it is efficient to use HVDC transmission for a very long distance compared to alternate currents.
Can DC Kill You?
Yes, direct current can electrocute you. When the high voltage is sufficient, it causes fibrillation or tissue damages, which can cause cardiac arrest leading to loss of life. We cannot compare the DC with the AC damages, which is more dangerous, as mentioned earlier.
But people usually mistake the low voltages like some of the household devices such as flat-screen television etc., to be harmful, which is not the case. Though we have skin resistance to current exposure over an extended period, more so when you are wet, the risk is usually high.
Which Is Better Between AC And DC?
More people worldwide prefer and are accustomed to AC rather than DC. Its ability to transmit high voltages over long distances, less power loss during the transmission process, and cheaper, safe and comfortable way to generate and convert its current to DC makes AC favorable.
However, DC is still relevant because of its low usage voltage, aircraft application and other specific applications where AC can’t be used. The best one will therefore depend on your needs and application.
Why Is AC Cheaper Than DC?
As compared to DC, AC has been proven to be much cheaper thanks to its electric current that is usually generated by the tremendous power plants and distributed using transformers. This makes it less costly to create with minimal energy losses, especially when transmitting electricity over long distances. The transformer can change the high voltage into a low voltage, suitable for household appliances like refrigerators and lights. Furthermore, the power can be converted easily to DC when there is a need, which the vice versa is not true.
Why Is AC Shock Attractive?
In nature, AC shock is not attractive. What usually happens when one holds onto or touches a live cable, be it AC or DC, is that the electric shock causes muscles to contract, making you grip onto the line, eventually getting one stuck. It’s essential to get out a victim immediately as you can to prevent death.
Can AC Appliances Run On DC?
Some AC appliances run on DC. It all depends on the type of appliances you have since other devices run on AC supply only, and if the DC supply is used, it will break down or not work. Most household and office appliances like washing machines, fan, mixer, bulbs, air conditioner, among others, run on AC supply only.
Some of the gadgets like laptops cell phones, to mention a few, work on the DC converted from the AC supply using the AC adapter or USB cables. Therefore, it is advisable to read the description of your appliance before plugging in your device to AC or DC power transmitters.
Final Word
Shifting from AC voltages to DC voltages is close to impossible. Globally everyone opts for the simplest method of transmitting power at a minimum cost while maintaining high efficiency, and AC offers that option. As much as DC voltage is gradually working on its inefficiency regarding the power supply across long distances, more is still needed for the practical result. Nonetheless, both have their specialty application, and it is for you to pick one based on the your desired application.
