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A power inverter changes DC (Direct Current) power from a battery into conventional AC (Alternating Current) power that you can use to operate all kinds of electrical devices such as lights, kitchen appliances, microwaves, power tools, TVs, radios, and computers to name just a few. You just connect the inverter to a battery and you've got portable power whenever and wherever you need it.

The AC power these inexpensive inverters produce is unsuitable for many applications. When selecting an inverter, spend a little more to get a significantly better, and safer, device. Consider quality the most important attribute when selecting your pure sine wave inverter. A modified wave inverter will not deliver reliable power portability for sensitive electronic equipment. The clean power delivered by a Pure Sine Wave is of the same quality and efficiency as the power provided by your utility company, this is not the case with the cheaper and more popular modified sine inverters.

The battery will need to be recharged as the power is drawn out of it by the inverter. The battery can be recharged by running the automobile motor, or a gas generator, solar panels, or wind. Or you can use a battery charger plugged into an AC outlet to recharge the battery.

True sine wave inverters (a.k.a. pure sine wave inverters) are manufactured to exacting standards to produce clean AC power from a DC power source. The AC output from a true sine wave inverter meets or exceeds grid power specifications with very low harmonic distortion.

What Are The Practical Differences Between Modified Sine Wave (MSW) And True Sine Wave (TSW) Output?

TSW inverters are about two to three times as expensive per watt, having a more sophisticated design, manufacturing requirements, and more expensive components.

A sine wave inverter is designed to replicate and even improve the quality of electricity supplied by utility companies. To operate higher-end electronic equipment, a sine wave inverter is recommended.

Advantages of Pure Sine Wave Inverters over Modified Sine Wave Inverters:

  1. Output voltage wave form is pure sine wave with very low harmonic distortion and clean power like utility-supplied electricity.
  2. Inductive loads like microwave ovens and motors run faster, quieter, and cooler.
  3. Reduces audible and electrical noise in fans, fluorescent lights, audio amplifiers, TV, Game consoles, Fax, and answering machines.
  4. Prevents crashes, weird print out, and glitches in computers as well as noise in monitors.
  5. Reliably powers the following devices that will not work with modified sine wave inverters:
    • Laser printers, photocopiers, magneto-optical hard drives
    • Certain laptop computers (check with your manufacturer)
    • Some fluorescent lights with electronic ballasts
    • Power tools employing "solid state" power or variable speed control
    • Some battery chargers for cordless tools
    • Some new furnaces and pellet stoves with microprocessor control
    • Digital clocks with radios
    • Sewing machines with speed/microprocessor control
    • X-10 home automation system
    • Medical equipment such as oxygen concentrators

We often are asked if computers will work with Modified Sine Wave. It's been our experience that most (with the exception of some laptops) will work though some monitors will have interference such as lines or a hum. However, if you have any doubt about any appliance, tool, or device, particularly laptop computers and medical equipment such as oxygen concentrators, we recommend that you check with its manufacturer to be sure it is compatible with a Modified Sine Wave inverter.

We highly recommend the use of Pure Sine Wave Inverters to power Computers and related peripheral devices; i.e. printer's, optical drives, laser copiers, and if in doubt check with the manufacturer of your equipment. Other devices that benefit when Pure Sine Wave power is used are variable speed control motors using solid state circuitry, Audio Amplifiers, Digital Clocks and Radios, Medical Equipment, Microwaves, etc.

Written by Hartley G. Lesser for

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