Sine Wave Inverter

What is a sine wave inverter

An inverter is the power-electronic device that converts direct current into alternating current at the output, with a waveform falling near the sine wave of a standard grid power supply. These kinds of inverters find broad employment in all sorts of duties where one needs a stable and high-quality AC power source, ranging from a home to an industry, a ship, a vehicle, and so on.

The main working principle of the sine wave inverter is an inverter bridge, control logic, and filter circuit. Among them, SPWM Technology is the key to generating a pure sine wave. Average output power regulated a change in the signal's duty cycle-that means in a high-level duration-generated a smooth sine waveform.

The differences between pure vs modified sine wave inverters

• Output waveform:
  • A pure sine wave inverter outputs a waveform similar to that of a perfect sine wave, with low harmonic distortion-only about the same as, or even better than, the AC waveform of the utility grid. This waveform has little interference with sensitive electronic equipment and will not cause computer crashes or monitor malfunctions.
  • While modified sine wave inverters have a waveform output, basically a square wave composed of a number of odd harmonics which are odd multiples of the fundamental frequency, such as 3rd (180 Hz), 5th (300 Hz), etc. Still a wave with considerable distortion that could damage some sensitive electronic equipment.
• Efficiency:
  • Pure sine wave inverters are normally based on a pulse width modulation technology, that characterizes their precise control and input and output isolation with increased efficiency.
  • Most modified sine wave inverter designs use non-isolated coupled circuits. These designs are less efficient but mostly cheaper.
• Applicable Equipment:
  • Pure sine wave inverters are convenient in all AC loads where any interference with radios, communication equipment, and precision equipment is very minimal. It can provide stable power to sensitive electrical equipment like laser printers, induction equipment, variable speed control equipment, and audio equipment.
  • Modified sine wave inverters can be used for simple resistive appliances such as toasters or incandescent light bulbs and also some electronic power supplies and devices that are to be used for brief periods of time. However, AC appliances based on motors and transformers can get heated up using Modified Sine Wave power and may even get damaged as a result of the same.
• Price:
  • Most pure sine wave inverters cost more since they offer high-quality waveform outputs. Their technical demands are greater, as well.
  • Modified sine wave inverters will be cheaper since it is less demanding technically and thus simpler in construction.

What does one consider when buying a sine wave inverter?

Output Waveform: The output waveform of a sine wave inverter is only similar to that of the utility-similar waveform with low harmonic distortion, very suitable for most electronic devices, especially those requiring high power quality like laser printers, computers, TVs, and others.If you have equipment that demands high power quality, then it is recommended that you go for a pure sine wave inverter.

Power Requirement: While choosing the inverter power, the sum of total power of all the equipment to be used should be taken into consideration with some margin. In general, it is recommended to choose an inverter whose power is 20-50% higher than the total required power against sudden rises of starting current.

Input Voltage: The input voltage of the inverter should be chosen to be the same as the output voltage of the battery or power supply. In this situation, there commonly exist three kinds of input voltages: 12V, 24V and 48V.

Protection Functions: For safe and longtime stable operation of equipment, over-voltage, under-voltage, short-circuit, overload and over-temperature protection functions are better.

Brand and quality: Choose inverters produced by well-known brands, like Jue Jue, to make sure the product quality is good and the after-sales service is in place.

Price-performance ratio: Even though pure sine wave inverters are more expensive, the performance can be very stable and suitable for long-time use. If you have a limited budget, you could consider Modified Sine Wave inverter, which is cheaper and with enough performance for general needs.

Form factor and installation: Choose the appropriate form factor regarding the installation environment and follow the relevant operational instructions during installation to avoid damaging the equipment.