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Can a Modified Sine Wave Inverter Damage Electronics?

Yes, some medical equipment and appliances that use AC motors are susceptible

By Jeremy Laukkonen Jeremy Laukkonen Writer Shoreline Community College Jeremy Laukkonen is automotive and tech writer for numerous major trade publications. When not researching and testing computers, game consoles or smartphones, he stays up-to-date on the myriad complex systems that power battery electric vehicles . lifewire's editorial guidelines Updated on December 23, 2020 Reviewed by Michael Barton Heine Jr Reviewed by Michael Barton Heine Jr Michael Heine is a CompTIA-certified writer, editor, and Network Engineer with 25+ years' experience working in the television, defense, ISP, telecommunications, and education industries. lifewire's editorial guidelines Tweet Share Email Tweet Share Email

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Expand Jump to a Section How Sine Wave Inverters Work Devices That Can Be Damaged Devices That May Not Work Devices That Typically Work Fine If you enjoy camping, having a pure sine wave inverter for your camper is quite useful so you can run your electronics while you are in the wild. Modified sine wave inverters can be found at a great price, but there is always the potential for damage to your electronic devices—which makes it necessary to learn as much as possible before you make your purchase. There are only two types of electronics that you need to be concerned about when using a modified sine wave inverter: appliances that use AC motors and certain classes of delicate medical equipment. If your electronics don’t fall into either of those two categories, then it's extremely unlikely that a modified sine wave inverter will do any damage. While a pure sine wave inverter is safe for use with a wider range of devices, the greater cost associated with pure sine wave inverters isn't always worth it. Kypros / Getty Images

How Sine Wave Inverters Work

Both pure and modified sine wave inverters take 12V DC from a battery and turn it into something that approximates the AC power normally available from the wall outlets in your home or business. AC stands for alternating current, which refers to the fact that AC power periodically changes direction. This can be visualized as a sine wave that gently rises and falls and swaps polarity instantly when it hits zero volts. In pure sine wave inverters, the AC power produced by the inverter very closely matches an actual sine wave. In modified sine wave inverters, the polarity abruptly switches from positive to negative. The simplest inverters produce a square wave, where the polarity is flipped back and forth, while other modified sine wave inverters create a series of steps that more closely approximate an actual sine wave. Since producing a modified sine wave is a much simpler process than creating a pure sine wave, modified sine wave inverters are typically much less expensive. The trade-off is that some electronics just don't work correctly or may even be damaged if they aren't powered by a pure sine wave.

Devices That Might Be Damaged By a Modified Sine Wave Inverter

While you’re probably fine using an inexpensively modified sine wave inverter in your camper, there are a few different things that you don’t want to run off a modified sine wave. Anything that uses an AC motor isn’t going to work to full capacity on a modified sine wave. Appliances like refrigerators, microwaves, and compressors that use AC motors won’t run as efficiently on a modified sine wave as they would on a pure sine wave. In some cases, running an AC motor on a modified sine wave may lead to a buildup of excess waste heat that could damage the equipment. You’re probably OK to use these devices with a modified sine wave inverter, but you do so at your own risk. The other main thing to be concerned about with modified sine wave inverters is delicate medical equipment. For instance, if you use a CPAP to help correct apneas when you’re asleep, you’re going to be better off with a pure sine wave inverter. Some CPAP manufacturers warn that you can damage your machine with a modified sine wave inverter, and others specify that the CPAP will work but the humidifier unit could be damaged. Other types of medical equipment, such as oxygen concentrators, also need a pure sine wave. In these types of cases, you’re better off using pure sine wave power or looking for a unit that can be powered by DC without the need for an inverter at all if it's available. Some devices suffer from unwanted interference from a modified sine wave inverter. You can power a radio with a modified sine wave inverter, but it may pick up interference from the modified sine wave, which could make it difficult to listen to.

Other Devices That May Not Work

Some other electronic devices that may or may not work correctly without a pure sine wave include: Devices that use thyristors like laser printers and photocopiersDevices that use silicon-controlled rectifiersLighting that makes use of electronic ballasts, like many fluorescent lights

Devices That Typically Work Fine

The list of electronics that usually work just fine with a modified sine wave is far too long to get into here. Suffice it to say that if it doesn’t use an AC motor, isn’t a delicate piece of medical equipment, and doesn't fit into any of the other no-go scenarios, you’re probably going to be in the clear. If the device that you want to power uses a rectifier to change the AC into DC, it’s extremely unlikely that you’ll have any issues. That means your laptop is probably going to be fine, although some manufacturers claim that not using a pure sine wave inverter will shorten the operational lifespan of the laptop power brick. If the device you want to power up runs on DC power in the first place, like a laptop, you're actually better off looking for a way to skip the transition from DC to AC and back to DC. If that seems complicated, it may be easier to think of it in terms of your cell phone. When you charge your phone in your car, you don't wire in an inverter and plug in your wall charger. You plug directly into your car's cigarette lighter socket, which is both easier and more efficient. Laptops and many other devices can also be powered directly from a DC power source in exactly this same way with the right adapter. Was this page helpful? Thanks for letting us know! Get the Latest Tech News Delivered Every Day Subscribe Tell us why! Other Not enough details Hard to understand Submit More from Lifewire Pure Sine Wave Inverters: Necessary or Overkill? Aeiusny Portable Solar Generator Review: Pure Sine Wave Inverter For Sensitive Medical Equipment What Is a Car Power Inverter, and How Does It Work? 12v Adapters vs. Inverters: Which Is Best? The 6 Best Power Inverters of 2022 How to Charge Your Phone or Laptop on a Plane What Are Diodes and What Are They Used For? What Are the Applications of Capacitors? Can I Use a Cigarette Lighter Inverter? The 8 Best Portable Generators of 2022 Wiring a Cigarette Lighter to a Battery Why Doesn't My 12v Socket Work? Picking a UPS (Battery Backup) for Your Mac or PC 10 Appliances You Can Plug Into Your Car How to Fix a Stuck Car Window How to Charge a Chromebook Without a Charger Newsletter Sign Up Newsletter Sign Up Newsletter Sign Up Newsletter Sign Up Newsletter Sign Up By clicking “Accept All Cookies”, you agree to the storing of cookies on your device to enhance site navigation, analyze site usage, and assist in our marketing efforts. Cookies Settings Accept All Cookies