The Difference Between (Alternative Current & Direct Current)

by Geeks_100 in Circuits > Electronics

4063 Views, 5 Favorites, 0 Comments

The Difference Between (Alternative Current & Direct Current)

2779466b3c9d61eb32bb7b6085bd7e22.jpg
AC vs. DC
Capture.PNG

Everyone knows that electricity is mostly Dc,but how about another type of electricity ? Do you know Ac ? What does AC stand for ? Is it usable then DC? In this study we will know the difference between the types of electricity, sources,application and history of the war between them and we will try to put an end on that war so let’s start.

Historical War ( AC is better,No Dc is perfect)
Welcome to the 1880s. There’s a massive war going down between Direct Current (DC) and Alternating Current (AC). This War of the Currents, like any other conflict in human history, has a set of competing ideas on how to best deliver electricity to the world. And of course, there’s a ton of money to be made along the way. So would Thomas Edison and his DC battalion hold firm, or would George Westinghouse and his AC Armada claim victory? This was a battle for the future of humanity, with plenty of foul play involved. Let’s see how it went down. Despite all of its wonderful uses in things like smartphones, televisions, flashlights, and even electric vehicles, direct current does have three serious limitations:

1)High Voltages. If you need high voltages, like what it would take to power a fridge or a dishwasher, then DC isn’t up for the task.
2)Long Distances. DC also can’t travel long distances without running out of juice.

3)More Power Plants. Because of the short distance that DC can travel, you need to install a whole lot more power plants around the country to get it in people’s homes. This puts folk living in rural areas in a bit of a bind.

These limitations were a huge problem for Edison as the War of Currents continued to unfold. How was he going to power an entire city, much less a country, when DC voltage could barely travel a mile without sputtering out? Edison’s solution was to have a DC power plant in every section of a city, and even in neighborhoods. And with 121 Edison power stations scattered across the United State,Tesla believed that alternating current (or AC) was the solution to this problem.

Alternating current reverses direction a certain number of times per second -- 60 in the U.S. -- and can be converted to different voltages relatively easily using a dangerous, even going so far transformer[1].Edison, not wanting to lose the royalties he was earning from his direct current patents, began a campaign to discredit alternating current. He spread misinformation saying that alternating current was more far as to publicly electrocute stray animals using alternating current to prove his point[2]

DC Current

g.PNG

DC Current

Definition:

is the one directional or unidirectional flow electric charge . An electrochemical cell is a prime example of DC power. Direct current may flow through a conductor such as a wire, but can also flow through semiconductors , insulators , or even through a vacuum as in electron or ion beams . The electric current flows in a constant direction, distinguishing it from alternating current (AC). A term formerly used for this type of current was galvanic current [3] .

Measuring Tools

h.PNG

The DC current can be measured by a multimeter .

The multimeter is:

connected in series with the load. The Black (COM) probe of a multimeter is connected with the negative terminal of the battery. The positive probe (red probe) is connected with the load. The positive terminal of the battery is connected with the load as shown in figure(3) .

Applications

[up.PNG

The various fields are listed as below:

DC supply used in many low voltage applications like charging mobile batteries . In a domestic and commercial building , DC used for emergency lighting, security cameras, and TV, etc.

● In a vehicle, the battery is used to start the engine , lights and ignition system. The electric vehicle runs on the battery (DC current).

● In communication, a 48V DC supply is used. Generally, it uses a single wire for communication and uses a ground for the return path . Most of the communication networking devices operate on the DC current.

High voltage Power Transmission is possible with the HVDC Transmission line. There are many advantages of HVDC Transmission systems over conventional HVAC Transmission systems. An HVDC system is more efficient than an HVAC system , as it does not experience power losses due to the corona effect or skin effect .

● In a solar power plant , energy generated in the form of DC current .

● The AC power cannot be stored like DC. So, to store electrical energy , DC is always used.

● In a traction system, the locomotive engines are run on DC current . In diesel locomotives also, the fan, lights, AC, and sockets are operating on DC current [4] .

AC Current

ff.PNG

Definition:

is an electric current which periodically reverses direction, in contrast to direct current (DC) which flows only in one direction. Alternating current is the form in which electric power is delivered to businesses and residences.

Measuring Tools

oo.PNG

It can be measured by a multimeter as DC current.

Any ammeter must be connected in series with the circuit to be measured. In some cases this becomes complicated, because you have to open the circuit and insert the ammeter. There is a way to measure current without opening the circuit, if you use a Clamp Meter . To measure current with this instrument, all you have to do is to clamp it around the wire to be measured, without opening the circuit. Be careful to avoid electric shocks or short circuits , once the circuit will be energized.

Applications

AC solves the serious limitations with DC

Producing and Transporting electricity.

● AC current travels well over short- and medium-range distances, with little loss of power.

● A major advantage of alternating current is that its voltage can be modified relatively easily using a transformer, which allows power to be transmitted at very high voltages before being taken down to safer voltages for commercial and residential use.This minimizes energy losses.

AC Generation

ii.PNG

To generate AC in a set of water pipes, we connect a mechanical

crank to a piston that moves water in the pipes back and forth (our "alternating" current). Notice that the pinched section of pipe still provides resistance to the flow of water regardless of the direction of flow. F igure(8): Ac Voltage generator . Some AC generators may have more than one coil in the armature core and each coil produces an alternating emf. In these generators, more than one emf is produced. Thus they are called poly-phase generators.In the simplified construction of three-phase AC generator, the armature core has 6 slots , cut on its inner rim. Each slot is 60° away from one another. Six armature conductors are mounted in these slots. The conductors 1 and 4 are joined in series to form coil 1. The conductors 3 and 6 form coil 2 while the conductors 5 and 2 form coil 3. So, these coils are rectangular in shape and are 120° apart from one another.

AC Transformer

tt.PNG

An AC transformer is an electrical device that is used to change

the voltage in alternating current (AC)to (DC) electrical circuits . One of the great advantages of AC over DC for electric-power distribution is that it is much easier to step voltage levels up and down with AC than with DC. For long-distance power transmission it is desirable to use as high a voltage and as small a current as possible; this reduces R*I2 losses in the transmission lines , and smaller wires can be used, saving on material costs.

AC to DC Converter

pp.PNG

Use one of the rectifier circuits ( half wave, full wave or bridge rectifier ) to convert

the AC voltage to DC . ... Bridge rectifiers will convert it into DC,there will only be 2 diodes working at any time so voltage output of the transformer will drop down by 1.4v (0.7 for each diode).

Types of Rectifiers

ee.PNG

DC to DC Converter

hh.PNG

is an electronic circuit or electromechanical device that converts a

source of direct current (DC) from one voltage level to another. It is a type of electric power converter . Power levels range from very low (small batteries) to very high (high-voltage power transmission) .

Summarize

oooo.PNG

From this study we conclude that both AC and DC have many applications,no one

is better than the other, everyone of them has its own application.Thanks to Tesla and Edison to produce these types of electricity,also thanks to technology that found ways of conversion between them.

References

[1] - https://www.autodesk.com/products/eagle/blog/war-...

[2] - https://www.energy.gov/articles/war-currents-ac-v... 0late%201880s,the%20War%20of%20the%20Currents.&text=Direct%20current%20is%20not%20ea sily,the%20solution%20to%20this%20problem

[3]- Basic Electronics & Linear Circuits

[4]- https://nanopdf.com/download/direct-current-sourc...

[5]- https://nanopdf.com/download/direct-current-sourc...