Pure Sine Wave Inverters VS. Modified Sine Wave Inverters

What Kind of Power Inverter Do I Need? A Simple Look at Pure Sine Wave Inverters vs. Modified Sine Wave Inverters

There are loads of articles available online that dissect the difference between what they call pure sine wave power inverters and modified sine wave power inverters. For many users, they just want to know if they can choose a less expensive modified sine wave power inverter and still run their devices. This article takes a look at the basics.

All power inverters convert DC power (which is power stored in batteries) to AC power, which is the power supplied by the electric company and fed to your home. Electronic devices need AC power to operate, but power inverters generally output power in two forms, modified sine wave vs. pure sine wave.

Simply put, pure sine wave power flows in even, arching waves, whereas modified sine wave power flows to your devices in chunky, square waves. The square waves are giving power to your device “all or nothing,” so to speak. Your device will run properly, or not. The power is coming through in a less seamless fashion. Gaining power that is flowing in modified sine waves does not come through as clean and efficient—it doesn’t flow to the device as “pure.” The devices will
get the power they need to operate, but when it comes to devices like fans, TV’s, radios and lights, they will tend to buzz, as they are running a bit “hotter,” due to the way power flows to them.

The cons of running your devices on modified sine wave power is that they will run less efficiently, which will commonly result in the device or appliance not running properly, interference or a “buzz”. For devices that aren’t sensitive, like a vacuum or water pump, it might not matter to you at all. They will use a little more wattage and make a little more noise. But, for devices that need an even flow of energy to function properly, like variable-speed power tools, you are going to get all or nothing. No matter how tightly or softly you pull on the trigger to your power drill, it is going to be full-speed or off. This doesn’t mean that a blender with different settings can’t be used at a high or low setting; it certainly can. But because they are getting energy that is less efficient, the devices you run on Modified Sine Wave power can wear out sooner than if they were constantly operating via pure sine wave power, like that supplied in homes.

Some devices and appliances that require a pure sine inverter are:

• Microwaves
• Laser printers
• Variable speed tools
• Cordless tool battery chargers
• Some TV’s
• Key Machines
• CPAP machines with humidifiers
• Medical equipment
• Sensitive electronics

The main “pro” in running your devices on modified sine wave power is that the modified sine wave power inverter costs you less initially.

When considering pure sine wave DC to AC inverters vs. modified sine wave DC to AC inverters, the conversation can lead you into a geeky look into a side of electricity and power you never cared to see. However, consider the types of devices you’re running and weigh your options accordingly.

If you have a device that you are unsure of whether or not it requires a pure sine wave inverter, give us a call.