With summer arriving in full flow, the power cuts are expected to get worse. The use of air conditioners and other cooling equipment in houses is expected to put a massive load on the electric grid, and electric cuts are a frequent occurrence. After all, there is nothing worse than having to sleep at night without even a fan to give you relief from the unrelenting heat.
A simple solution to enjoy power when electricity supply is cut off is the use of a UPS. A UPS will store charge when there is power and will use the stored charge to power the various appliances around your house.
The electricity that comes from the electricity grid is different as compared to that stored in batteries. Let’s get a brief overview of the two types of current.
Alternation Current or AC
This form of current is propagated as a sinusoidal waveform. It is the go-to form for transmission since there is very less power loss. It can travel hundreds of kilometres with negligible loss, and its development by Nikola Tesla was critical in ensuring that cities and homes could be powered by electricity. The primary disadvantage of this current is that it cannot be stored efficiently.
Direct Current or DC
This form of current is the one that is stored in batteries. It is unsuitable for long distance transmission but is the best way to save in cells. The typical 1.5-volt batteries that you find around your house provide direct current.
Now that you’re aware of the basics let us get into the process of storage in a UPS. The AC coming from the electricity board must be stored. This means that it must be converted to DC. A special circuit known as rectifier helps to turn the AC to DC and is stored in the battery. When the charge is required, the DC is reconverted back to AC using a device known as an inverter. The inverter converts the straight line DC back to the sinusoidal AC that can be used by the various electrical appliances in the house.
The inverter is one of the vital components of the UPS. There are several types of inverters available.
- Square Wave
These are generally considered the lowest quality inverters and are also the cheapest. They convert the DC back to a sinusoidal, except that it resembles a square wave more than a sine wave. For hardy devices such as motors, this works fine, but for home appliances, the harmonics cause a lot of heating and buzzing.
- Modified Sine Wave
These are a step higher than the square wave inverters. They produce a higher quality waveform but still aren’t optimal for use at home since the waveform isn’t a pure sine wave, but more of an approximation.
- Pure Sine Wave
Pure sine wave inverters are the best and most expensive inverters available. They produce a perfect sine wave and replicate the power supply from the electricity board perfectly. Some devices such as phone chargers and toasters require an ideal sine wave to operate, and this is the perfect device to achieve that.