For the avid camper, carrying a high-quality alternating current power inverter is crucial to bringing maximum fun to the weekend camp.
An alternating current power inverter can also be precious if you often experience power failures or occasionally go off the grid for work or other missions.
So, what is an alternating current power inverter? Here’s our guide to help you get to grips with this tremendously beneficial electric equipment.
What does an Alternating Current Power Inverter do?
The AC power inverter connects to a typical DC supply like your car battery and takes the power from such a source and converts it to alternating current thus its name.
So, why this conversion?
If you plug in a household appliance like your toaster oven to the 12v battery when the mains power goes off, you can be sure you’ll have to take breakfast without toast.
That’s because the construction of these devices can only operate when fed with the alternating current (AC) that comes from the mains and not the direct current (DC) from the battery or solar panels.
This begs the question: what’s the difference between AC and DC current and why can’t these devices run on DC?
Well, DC flows in one direction all the time while AC always switches directions (forward/backwards).
I don’t want to go into the detailed physics about how the direction comes about so let me go straight to the biggest reason why DC won’t suffice for machines like coffee makers and computers. Now, the output from the DC sources is typically lower than what’s needed by some electronics, kitchen gadgets, and tools.
The inverter plays an important role as its output voltage is higher and equivalent to the household plug-in voltage the utility company power lines deliver to your home.
The alternative current being produced by the inverter should be enough to run hundreds of devices hence the ever-rising popularity of this accessory.
What are the parts of an alternating Current Power Inverter?
There are a few different types of AC power inverters available, but the design is very similar.
Transistors, resistors, capacitors, and a couple of other circuit devices are what make things work during the voltage ‘amplification’ and the power conversion process.
Lately, most AC power inverters have been added with advancements such as under-voltage and overvoltage protection to prevent sensitive equipment from being harmed by power surges and such issues as well.
How does an alternating Current Power Inverter work?
As explained above, an AC power inverter does not make any power on its own and just transforms the energy generated by a DC supply.
There are two DC to AC inverter circuit designs for the operation:
The first uses a switching step-up converter to give off a higher voltage direct current. It then converts this to an alternating current.
The other design converts direct current to alternating current at the battery level and then creates the matched AC output voltage using a transformer.
What type of AC power inverter should I select?
In the market today are three types of inverters.
To differentiate them, we mainly look at the waveform (the shape representing how the alternating current varies with time).
Take a look:
1. Square wave AC power inverters
Here the electricity will have a constant force and is considered too choppy.
They actually produce some ‘humming’ when hooked up to audio equipment and are bad news for all sensitive electronics (these don’t like ‘dirty’ power supply and could easily get damaged if fed with such power).
As a result, these days you’re unlikely to find this outside of low-sensitivity appliances such as lighting (bulbs) and heating (some heaters). However, given they were the standard for many years, they’re still worth talking about.
2. Pure (or true) Sine wave AC power inverters (PSW inverter)
These produce a perfectly smooth sine wave voltage continuously and the current is as clean as that channelled by power stations making it the best choice for the most sensitive electronics.
These include laser printers and most of the tools with motors (these – including light-duty power tools- could easily get damaged if charged up with such power).
3. Modified sine wave AC power inverters (MSW inverters)
These are in between and produce a wave form that’s somewhat stepped (neither smooth nor square).
And while it’s a massive upgrade on the extremely rough square waveform, the output here is still noticeably uneven and could hurt digital clock radios, fridges, coffee makers, and most of other sensitive appliances.
Smoothing out the waveform from modified sine wave inverter
Some devices run better with the mounting of line conditioners (choke or transformer) on MSW inverters, so that’s something you can consider because PSW AC inverters are super expensive.
Sure, they might not always function as well as when on PSW inverters but they won’t be damaged.
What are the common power inverter capacities?
One key thing to consider is the power inverter output capacity because it won’t work if it doesn’t match your expected load. The most common sizes are 500 Watts, 800 Watts, 1000 Watts, and 1500 Watts.
You may sometimes come across 3000 Watts and 5000 Watts but you’re likely to find more people with the earlier sizes as they’re adequate for small to medium electrical loads.
Of course, you must consider the expected draw of all your appliances before settling on the best capacity. And the more they’re, the more the required output capacity.
Power-hungry devices such as refrigerators will certainly take more power meaning you could be forced to invest in one of the models with the highest wattage rating.
Overall, the safest alternating current power inverter to buy is one producing pure sine wave.
But they’re quite costly and generally out of reach if you’re under a budget.
MSW inverters are the other option and even though they work pretty well with a range of devices, you might be risking items like microwave ovens, some fans, gaming devices, and laser printers.
That brings me to a less costly alternative way of running your equipment out there: a generator.
It could be more effective with certain appliances and is above all going to potentially save you hundreds of bucks compared to using an inverter.
U.S. Department of Energy: Solar Integration: Inverters and Grid Services Basics