Quasi Inverters

Modified Sine Wave Inverters

Listed below are Modified or Quasi Sine Wave inverters

Quasi inverters are sometimes also known as modified sine wav inverters which convert 12v up to mains level voltage of 220-240v.

Modified Sine Wave Inverters range from simple cheap portable units that plug into your cigarette lighter, up to more expensive hard wired units that are permanently installed.

Motorhome inverters vary in size and quality but are of two basic genres, modified sine wave models (aka Quasi Sine Wave) & full sine wave

Modified Sine Wave inverters produce an output wave form that is close to a true sine wave and will work adequately with most devices, including TVs and computers.

The disadvantages of a modified sine wave inverter are that you may experience some slight distortion lines on a TV or hear a slight buzz on the stereo. Some equipment that is particulary sensitive to the non ideal waveform may suffer such as those with built in motors like electric toothbrushes or senstivie electronics like laptops etc. Full sine wave inverters have a much smoother output waveform and are therefore suitable for all purposes although they do come with a higher price tag due to the increased circuitry present within the units.

The advantages of an inverter over a generator are the lack of noise and zero operating costs once purchased.

What size inverter should I buy?
Short Answer: The size you choose depends on the watts (or amps) of what you want to run (find the power consumption by referring to the specification plate on the appliance). We recommend you buy a larger model than you think you'll need (at least 10% to 20% more than your largest load).

Example: You want to power a television, some lights, and a radio.

Television: 50 Watts
2 - 60 Watt lights: 120 Watts
Radio: 10 Watts
Total Needed: 180 Watts

For this application, you would minimally need an inverter capable of supplying approx 200 Watts, you should give some thought to a larger one, as there will likely be a time when you wish you'd bought a bigger model.

Longer Answer: Determine Continuous Load and Starting (Peak) Load: You need to determine how much power your tool or appliance (or combination of them that you would use at the same time) requires to start up (starting load), and also the continued running requirements (continuous load). Things like Microwaves have a very high Starting Load but then level out to a substantially lower Load.

What is meant by the terms "continuous-2000 watts" and "peak surge-4000 watts" is that some appliances or tools, such as ones with a motor, require an initial surge of power to start up ("starting load" or "peak load"). Once started, the tool or appliance requires less power to continue to operate ("continuous load")

Helpful formulas:

To Convert AMPS to WATTS:

Multiply: AMPS X 120 (AC voltage) = WATTS
This formula yields a close approximation of the continuous load of the appliance

To Calculate approximate Startup Load:

Multiply: WATTS X 2 = Starting Load
This formula yields a close approximation of the starting load of the appliance, though some may require an even greater starting load. NOTE: Induction motors such as air conditioners, refrigerators, freezers and pumps may have a start up surge of 3 to 7 times the continuous rating. Most often the start up load of the appliance or power tool determines whether an inverter has the capability to power it.

For example, you have a freezer with a continuous load of 4 amps, and a start up load of 12 amps:

4 amps x 120 volts = 480 watts continuous
12 amps x 120 volts = 1440 watts starting load

You would need an inverter with peak-surge rating greater than 1440 watts.

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