How Does a Power Inverter Work?

To the uninitiated power inverters can seem a little confusing.

Once you understand that basics, they in fact couldn't be simpler to operate.

But you still might be wondering exactly how a power inverter works, so we've put together this short guide to walk you through everything you need to know about how power inverters work. 

The History of the Power Inverter

Thomas Edison is one of the pioneers in the field of electricity in America, with his inventions and discoveries becoming popular in latter part of the 19th century. His is most popular for insisting on DC, or Direct Current as the better way to supply electricity rather than AC.

Alternating Current. The latter was supported by one of his stiffest rivals, Nikola Tesla. Edison pulled out all the stops just to prove that AC current was dangerous, and proved so by electrocuting an elephant, and even the use of such current in the implementation of the electric chair as a death penalty. Despite that, it was Tesla’s AC system that won, and to date, it still is the primary method through which electricity is supplied to homes.

Indeed, most of today's gadgets are powered with AC. Small-scale power generators, however, can produce DC. This means that you would need a device to be able to convert the current from DC to AC, and vice versa. This is device is called an inverter and has proven to be so effective and useful in today's world. With that said, let's go deeper into the details as to how these gadgets work.

DC vs AC

Direct Current is the one which is usually explained first whenever we talk about DC and AC in the Academic Realm, due to how simple the explanation is. It's described as a flow of electrons. These electrons then behave like ants which walk along with packets that contain electrical energy, the same way through which ants carry with them leaves or even food.

This type of comparison is similar to a basic flashlight, where circuits that link a lamp, battery, and switch enable the transportation of electrical energy, from the voltage source, which is the battery, to the output, which is the lamp, until all of the energy stored in the battery has been used up.

Most household appliances, however, work in a much more complicated manner. The power supply, which is usually sockets in your wall is based on AC. The electricity switches regarding direction at a rate of 50 to 60 times per second, which is the frequency.

The frequency rate is measured in Hertz, and the usual rate is therefore 50 – 60 Hz. It can be difficult to wrap your head around AC connections, given that the energy delivery isn't steady or constant, but rather, always changes direction. So how then, will this be able to power up devices?

The Basics of a Power Inverter

These inverters convert DC into AC. The former is usually power which comes from a car battery, and the latter is what most electronics usually need for them to function. Getting a right one is crucial, as getting it wrong can result in damage for your electronic appliances.

Which one is best for your set of appliances? What is the right way to install a power inverter? Exactly how does the whole conversion process happen? We'll get to see all of the possible angles for AC and DC power inverter analysis in this article.

The Process

Now let’s have a look at the basics there are to power inverters in more specific details.

In simpler terms, converting a DC-giving battery to be able to provide an AC would mean placing some form of switch straight out the output lead to easily switch the current off and then on again at a fast yet steady rate. This would enable direct current to come in pulses, at least. If you wanted to want to take things up a notch and convert it the real way, you would need a real switch that would be able to reverse current for around 50 to 60 times a second.

Mechanical inverters back in the day work this way, where a switch that lets you do such a job will be connected to a transformer of some sort. Essentially, they do this through electromagnetics, where low-voltage to high-voltage AC conversions are made possible through electromagnetic devices, which are primarily two wire coils which share a common iron core.

These mechanical inverters make use of an electric motor that allows current to be flipped back and forth, which is somewhat like an electric doorbell. The power then gets connected, the switch gets magnetized, and then for a very brief amount of time, the switch gets pulled open and then switched off.

The spring then pulls the switch back into position, turning it on. This then gets repeated, again and again.

How to Install a Power Inverter

Inverters are easy to install. For small devices, all that has to be done is to "plug and play," especially for those that are of low wattage. These inverters are equipped with a plug which fits the plug that’s dedicated to the cigarette lighter. No mounting is usually needed for smaller devices, as they are made to be carried from one place to another.

An inverter that allows for higher wattages would entail installation, specifically for those that are designed to handle more than 400 watts. This is because, for devices with higher watt ratings, a more direct connection would be necessary. The input cables of inverters have clips that are attachable to battery terminals, where the inverter can still be mounted in any place where good air flow to the device can be guaranteed.

This is because high-power inverters would emit a lot of heat, and a well-ventilated area is necessary to prevent overheating from taking place. As a matter of fact, even larger inverters have holes that are dedicated for bolting it to a surface.

Larger inverters may require you to have your converter bolted in place, though it may not be necessary at times. You can just place it somewhere where there is a stable, and secure position for you to securely clip the inverter's leads to the battery, and plug the devices you want to be used in.

Inverters are fairly common, and you might have encountered them without knowing that they are. The smallest ones can fit in your pocket, and some of them, those with a higher wattage are as big as a dictionary. Basically, the higher the wattage rating, then the heavier and larger the inverter is. Some of the biggest ones for home use can weigh 30 pounds, and have a length of as much as two feet.

For ease of use, a lot of modern inverters are equipped with various safety features. Some of these include an alarm system that goes off whenever the battery voltage becomes too low for the device to function properly. While it makes things more convenient, knowing battery levels are also extremely crucial in the operation of certain devices, especially those who are sensitive to the flow of electricity.

Some of these inverters, apart from having alarms, also have automatic shut-off capabilities as well, which can prevent the device from exploding in times of overheating or overloading, which is often the cause of fires.

Some inverters can also shut down when wet, or when a metallic piece will fall into the chassis. Also, to not electrocute owners, short-circuit shut-off features can also come in handy.

Power Inverters for Car Use

One common application for power inverters is for automobiles. This is because the power that is generated by a car's battery is in DC, and most devices are in need of AC to get running.

A car power inverter will help you get AC appliances to power up when on the road. If you have one, it would be extremely easy for you to get an electronic device you would normally use at home or in the office, get it plugged in the car, and this is able to use it like you normally would.

You still have to remember the basics there are to battery operations though, such as car battery capacity, alternator’s rated output, and the inverter’s output wattage.
The electrical system is just able to emit a limited amount of power, and the battery would eventually go dead. These are some things that you have to consider and keep in mind whenever you are on the road.

Those who are always traveling will make use of one type of inverter, and these devices do come in handy whenever you are on the road, or when you want to go on business travel, or if you are a truck driver who goes over-the-road, and the like.

There are several other components that can get connected and powered up with a cigarette lighter or an accessory circuit, but due to the battery of the automobile having a limited capacity, there are limitations as to what can be connected.

Heavy-duty applications require a direct connection between the inverter and the fuse panel. Some of these panels have empty slots that an inverter can be connected to, and this will help to provide a special circuit for the said device. In some instances, an inverter could also be connected to the batter directly through a fuse that is in-line. Whichever the connection type, make sure to use a fuse with the right Ampere rating to prevent a dangerous situation from taking place.

One thing you also have to remember is that trucks and cars aren't designed to accommodate inverters. Also, keep in mind that the battery also has set capacities. Should an inverter be used when the vehicle is not running, it can deplete the battery quickly.

There also are some trucks that come with additional space beneath its hood if you want to place an extra battery, should you need more power or if your battery would fail. This could also help power up the inverter, and the devices plugged into it, though it isn't an option that's available everywhere.

To make sure that the problem is avoided, to begin with, always make it a point to have the output of the alternator checked, and from there get the inverter that fits the requirements. There should also be an OEM option which allows for an alternator with a much higher output rating. You can also make use of certain aftermarket units that allow for more power.