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What's the difference between AC & DC?

This entry was posted on 19/03/2020 03:54:24 PM by Valen

Whats the difference between AC & DC

Alternating current (AC) and direct current (DC) are notable for inspiring the name of an iconic metal band, but they also happen to sit right at the centre of the modern world as we know it. 

But what's the difference between the two? In this blog, the experts at Valen take you through the difference between them and where they're used today. 


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Think of five things you do or touch in a day that doesn't involve electricity in any way, were not produced using electricity, and are not related to your own body's internal uses of electricity ... Nice try! But there's no way! (Send us a list if you think you can!)

Electricity or 'current' is nothing but the movement of electrons through a conductor, like wire or cable. The difference between AC and DC lies in the direction in which the electrons flow. 


So the difference is...

In DC, the electrons flow steadily and continuously in a single direction, or 'forward'.

In AC, electrons keep switching directions, sometimes going 'forward' and then going 'backward'. 

AC vs DC

A simple way to visualise the difference is that, when graphed, DC current looks like a flat line, whereas the flow of AC on a graph makes a wave-like pattern. AC switches overtime in an oscillating repetition - the up curve indicates the current flowing in a positive direction and the downward curve signifies the alternate cycle where current moves in a negative direction. 


Where are they used? 

AC Current

The outlet in your office uses AC. This is because the source of the current came from far away, and the wave-like motion of the current makes it an efficient traveller.

DC Current

A battery has negative and positive terminals, and the electrical charge moves in one direction from one to the other at a steady rate.

If you're reading this on a laptop, you are using both kinds of current! The laptop charger delivers direct current to the battery, but it receives that charge from an AC plug that goes into the wall. The block that's in between them is a power adaptor that transforms AC to DC. 


Use of transformers with alternating current

Another difference between AC and DC involves the amount of energy it can carry. 

A battery is designed to product one voltage, and that voltage of DC cannot travel very far until it begins to lose energy. 

But AC's voltage from a generator can be bumped up or down in strength by another mechanism - a transformer. Transformers change very high voltage into a lower voltage appropriate for your appliances and electronics. 


Need advice on industrial energy products or requirements? 

Every project or application is different, so it's essential to ensure your system will run to the maximum efficiency and deliver value for money. The experts at Valen are proud to offer the highest level of technical support. We have comprehensive knowledge within the industrial energy sector. 

To talk to one of our trained team members, simply click here to get in touch

Written by Valen

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