‘What is the difference between AC and DC electricity ?’ is a question we get asked a lot at ELe, so we thought we’d put it into a blog…
AC, in other words, alternating current is a flow of charge that is constantly changing direction. This means it is good for mains electricity as the electricity can flow in either direction.
Mains electricity is the electricity that flows into the household from the national grid. It enables you to use your electrical appliances, such as your toaster or microwave. It’s not useful in situations when using electronics where you want the current to flow one way into the appliance.
DC, or direct current, is where the current only flows in one direction. So this is used in batteries as you don’t want the current to flow back into the battery. This is because you want all the power flowing only into the appliance.
DC is useful in the way that it will provide the maximum amount of power to the appliance as possible. There is only one direction the current can flow in, where as AC provides current in more than one direction. So this means not all the power will go to one place. For electronic devices to run off AC electricity you will require an additional AC to DC converter, or power supply.
If you’re still struggling to remember the difference between AC and DC electricity think of it like this:
Canal boats are big and long and can only sail one way down a narrow canal. So this would represent the direct current as both can only go in the given direction. But imagine speed boats that are small and quick and can turn around travelling in any direction along the canal. Thus would represent the alternating current as they can flow in either direction.