Alternating & Direct Current: What’s the Difference?

Nearly all electricity you encounter consists of one of two types of currents. Alternating Current (AC) and Direct Current (DC) have their distinct advantages, and disadvantages. AC and DC have a fascinating and storied history. Both AC and DC had their proponents and were embroiled in a struggle for supremacy and widespread public use.

What is Alternating Current?

AC stands for Alternating Current, alternating current, unlike direct current, can flow in both directions. Alternating current also allows for voltage to be increased or decreased with the use of transformers. This makes AC the ideal electricity form to be efficiently transmitted through power lines at a high voltage. AC is further beneficial for this purpose as it reduces the amount of energy lost to heat and increased resistance.

Because transformers can only be used in AC power systems, all homes in Australia run on Alternative Current. The AC in most homes and offices have an oscillating voltage in the form of a sine wave. This means that transformers can be used to supply the correct voltage to every electrical appliance or outlet within the home.

What is Direct Current?

DC Current or Direct Current supplies a continuous steady electrical current, always flowing in the same direction. DC always flows across wires from positive to the negative terminal and continually in the same direction. The most commonly used example of DC is any current that flows from a battery. Hence batteries having positive and negative charge symbols denoting the direction of electrical flow.

The war of the currents:

The competition between these two transmission systems dates back to the late 1880’s when the struggle between two major opposing energy firms for widespread adoption of their own patented energy systems. This struggle for market dominance leads to propaganda, and misinformation campaigns.

Thomas Edison owned a considerable number of patents for his inventions but all of his patents were for DC systems. Edison sought to demonstrate the danger of AC. Edison expressed the view that AC systems supplied too high voltage electricity and it was too dangerous for widespread commercial use.

In order to try to deter the spread of AC systems in DC covered territories, he engaged in a number of disturbing public displays demonstrating the dangers of AC. In one of these displays, Edison electrocuted an Elephant in Coney Island Amusement Park to show how dangerous AC could be. Eventually, AC systems prevailed because of the lower cost and higher efficiency in the transfer of energy over vast distances.

The Modern Day Both AC and DC are utilized for different purposes

In the modern day, different appliances utilize different forms of current, and some devices use both current types simultaneously. However, all the electricity coming into the home arrives as Alternating Current. Alternating Current is more easily adjusted to lower voltages. Alternating current allows all outlets and appliances to get the right type of current and the correct voltage for their demand.

In much modern technology, a combination of AC and DC is employed. For example, laptops typically run utilising DC but have to transfer the mains AC to DC to charge their battery. The AC is converted from the plug into DC via the little box in the middle of the cable, so it can be utilised safely within the circuit boards inside the laptop as well as to charge the laptop’s battery. This is why with use the power adapter leading to your laptop generates heat.

Contemporary electricians have to have in-depth knowledge of AC and DC currents and setting-up rectifiers to transfer AC to DC. They also have to have sufficient expertise to ensure all outlets in a building will receive the correct voltage, and the electrical system will run smoothly and safely. This makes Electrician an incredibly learned and skilled profession, especially to the level required to rewire a house.

Traditional incandescent lighting runs directly from AC from the mains. LED lights typically rectify the AC power converting it to DC to operate. The power supply has to be set up properly so that the rectifiers operate as they should otherwise your home could be at risk of light failure or even fires. This is why if you’re considering installing LED lights in your home you should always use a fully trained master electrician.

Another reason you should always use an expert electrician is to ensure the quality of the DC power supply an LED light receives. Poor quality DC may cause LED lights to flicker. Excessive exposure to flickering LED lights may contribute to headaches, mental strain or even epileptic episodes in sensitive individuals.

With over 20 years of experience, Northern Lights Lighting & Electrical, we have all the expertise and knowledge to provide superior quality and competitively priced electrical solutions for your home or business. From complete house or Business wiring to LED light installations. Call us on 0800 177 275 or enquire online today for your free, zero obligation quote.

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  • Avatar Douglas Rawson ★★★★★ 3 months ago
    Simply Awesome service from Northern Lights. We had quite extensive work done on our home, including rewire, new board, new main line point of entry, new earth, all light fittings, switches and power points … More replaced, new indoor and outdoor lighting installed. When quoting, John was fantastic and listened to what we wanted. He didn't try pressure us or upsell to us. He took the time to explain things and give us options that fitted our budget. The electricians who carried out the work were also fantastic. Over the 5 days, Hannes, Matt and Zio were on time, polite, professional, and tidy. Their work was top notch and their attention to detail was awesome. We also changed our mind a bit along the way and they accommodated this for us no problem. Going forward we will be using Northern Lights for any and all electrical work in the future. We really couldn't be happier! Thanks Guys!!
  • Avatar Mike Foster-Atkins ★★★★★ 4 months ago
    Team arrived promptly, were thorough and professional and left everything neat and tidy afterwards. New lights look awesome.
  • Avatar Karl Crawford ★★★★★ 4 months ago
    Great, prompt and friendly service. Would recommend and use again

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