Posted on Category:UPS

Understanding the Difference Between Pure Sine Wave and Modified Sine Wave Inverters

If you’re in the market for an inverter, you may have come across the terms “pure sine wave” and “modified sine wave.” But what exactly do these terms mean, and how do they differ from one another?

In simple terms, an inverter is a device that converts direct current (DC) electricity, which is the type of electricity stored in batteries, into alternating current (AC) electricity, which is the type of electricity that is used in your home or business. This is useful if you want to power your appliances or electronics using a DC power source, such as a solar panel or a battery.

Pure sine wave inverters are designed to produce AC electricity that is virtually identical to the AC electricity that you get from your power grid. The waveform of this electricity is a smooth, sinusoidal curve, which is why it’s called a “pure sine wave.”

Modified sine wave inverters, on the other hand, produce AC electricity that has a more choppy, triangular waveform. While this type of electricity is sufficient for most household appliances and electronics, it may not be suitable for certain types of equipment, such as certain medical devices, motors, or sensitive electronics.

“Sensitive electronics” refers to electronic devices that may be affected by the quality of the power they receive. These devices may include:

  • Medical devices: Some medical devices, such as certain types of defibrillators and respirators, may require a stable power source in order to function properly. These devices may not work properly with a modified sine wave inverter.
  • Motor-driven appliances: Appliances that have motors, such as refrigerators and washing machines, may run more efficiently with a pure sine wave inverter. Modified sine wave inverters may cause these appliances to run less efficiently and potentially shorten their lifespan.
  • Audio and video equipment: High-end audio and video equipment, such as amplifiers and HDTVs, may be sensitive to power fluctuations and may not perform optimally with a modified sine wave inverter.

On the other hand, many everyday household appliances and electronics, such as laptops, smartphones, and LED light bulbs, are not as sensitive to power quality and will work just fine with a modified sine wave inverter.

It’s important to consider the specific needs of your electronics and appliances when deciding between a pure sine wave inverter and a modified sine wave inverter. If you’re not sure which type of inverter is best for your needs, it’s always a good idea to consult the manufacturer’s recommendations or a qualified electrician.

So, which type of inverter should you choose? Here are a few things to consider:

  • Cost: Pure sine wave inverters are generally more expensive than modified sine wave inverters.
  • Compatibility: If you plan to use your inverter with sensitive electronics or equipment, a pure sine wave inverter is a better choice.
  • Power Quality: Pure sine wave inverters provide cleaner, more stable power, which may be important if you’re running sensitive equipment or if you’re sensitive to power fluctuations.

In summary, pure sine wave inverters offer the highest quality of power, but they come at a higher price point. Modified sine wave inverters are a more affordable option, but they may not be suitable for all types of equipment. Ultimately, the choice between a pure sine wave inverter and a modified sine wave inverter will depend on your specific needs and budget.

Posted on Categories:Lithium, Power Bank, UPS

Charge your Wi-Fi Router & laptop using a Power Bank

It is possible to keep your Wi-Fi on during loadshedding using a power bank, chances are you have one laying around already. This solution won’t be as elegant as using the UltraLan DC to DC Mircro UPS or the Ellies Cube, but it is certainly a good option especially if you have a power bank already and is keen to do some DIY.

Powering your WI-FI (keep your internet on during loadshedding) using a power bank

The concept is simple, you use a DC buck-boost converter (Chopper) to increase the voltage of your power bank from 5V to 9V or 12V depending on what your Router requires. Your mileage may vary.

If you want a simpler solution then this DC UPS is the way to go and if you want to power your laptop then this Laptop Backup solution is a good option.

How to find out the voltage of your router?

Look on the bottom of your Power Supply, there will be a sticker on it showing the Voltage and Amps that you will need to power the router. Take note that the Amp rating on the power supply is often time overstated and the actual router uses much less, this will be important later.

Tenda AC WiFi Router Power Supply
Tenda Wi-Fi router PSU

In the example above our Tenda Wi-Fi router has a power supply rated for 12V and 1A, this means we will need to set our boost converter to output 12V.

What is a Buck-Boost Converter & how will it be used?

A buck-boost converter is commonly used to create a constant DC output voltage from a variable DC input voltage source. In simple terms, it allows you to get a higher voltage out than what you are putting in or a lower voltage than what you are putting in.

DC-DC Boost Buck Adjustable Step Up Step Down Automatic Converter XL6009 Module Suitable For Solar Panel
Buck Boost Converter

The one we will be using is a buck and a boost converter, it combines the functions of a buck converter (used for DC voltage step-down) and a boost converter (used for DC voltage step-up).

But you can also use a normal step-up boost converter like the XL6009E1 based module.

  • If you are in Cape Town and surrounding area then you can buy one from Netram: Netram boost converter
  • If you are in Johannesburg and surrounding areas then you can buy from DIY Electronics: Buck-Boost converter

How to connect the power bank to your router using the boost converter

  • You will need a USB cable that you can cut in half, then plug the USB cable into the power bank, and the other end solder it to the boost converter ( actually, solder it first, then plug it in, hehe ).
  • Connect a volt meter to the other end of the Boost Converter and then adjust the potentiometer (blue box with screw) until the volt meter shows 12V or however many volts your router requires. The potentiometer has multiple turns. So it may take a while before you have reached the desired voltage. The potentiometer can rotate about 25x from start to finish.
  • Connect a wire to the other side of the boost converter and then either to a barrel dc jack or use a wire with one soldered on already. Make sure to connect to the correct positive and negative outputs on the boost converter.
  • Plug in your router.
  • Bob is now your uncle.
Powering a WiFi router using a power bank and a buck boost converter

Additional note on buck-boost converters

You can’t beat basic physics. You can’t make energy from nothing. In a steady state, the power (energy per time) out of a converter can’t be more than the power you put in.

Power in this context is current times voltage. In common units, Watts = Volts x Amps. If you put 2A at 5V into a converter, it is getting (2 A) x (5 V) = 10 W in. If it were 100% efficient, that’s what it would put out. If it puts out 12 V, then the current would be (10 W) / (12 V) = 0.83 A.

Of course, there is no such converter that is 100% efficient. The actual efficiency tells you how much of the input power (which is the same as the output power at 100% efficiency) it actually puts out. Let’s say this converter is 85% efficient. That means it puts out (10 W) x (80%) = 8 W, and at 12 V that would be 0.66 A.

This is where that earlier point comes in, the PSU of the Tenda does show 12V 1A, however luckily for us the router rarely pulls 1A and is closer to 0.5A which makes this a potential solution to power your Wi-Fi router, but you will need to do the same for your fiber ONT if you have that. If you have an LTE router then this solution will be fine.

Physics also says you can’t just disappear energy either. So the remaining (10 W) – (8 W) = 8 W has to go somewhere. In the case of a boost converter like this, it goes to heat. The 85% efficient power converter takes 85% of the input power and transfers it to the output, and heats itself up with the remaining 15% of the input power.

Keeping your laptop powered during loadshedding using a power bank

You can use this exact same concept for your laptop, however, you will need a much more powerful power bank as we have seen using the example above, you will need at the very least a 50-watt power bank. We do have some in stock, but I would much rather suggest you buy the WINX 100W Laptop Backup solution, it comes with a cable of your choice that can plug into one of the following brands: Dell, Asus, Acer, HP, and Lenovo laptops.

Posted on Categories:Lithium, UPS

Upgrade your UPS with a Securi-prod 7Ah Lithium Iron Phosphate Battery

Lithium powered UPS

Chances are you have an old UPS laying around which is no longer in use because the batteries inside are broken. Well, now you have a fantastic device to keep your TV or Router on during loadshedding by giving it new life using a Lithium battery.

This is a fantastic use case to give to your in-laws, to keep their internet on, a simple, easy, plug-n-play solution.

I replaced all our UPSes with lithium batteries & as a result, I can now power my Synology NAS during loadshedding.

This was an incredible discovery for me because I was always worried about the damage being done to my harddrives by Eskom by not having a backup solution for my Backup Drive Station. Some might not realise this, but a UPS is basically an inverter and charger, much like the ones everyone is currently buying all over the place.

A Mecer / Trolly Inverter will be able to handle a much larger battery like the 100Ah ones and their efficiency will be much better, but the UPSes you have at home or at the office can still be an incredible device if you pair it with a lithium battery, definitely an all-in-one device for your WiFi and Laptop to work from home during loadshedding.

This same principle can keep your internet on for at least 5 hours. I have a Mikrotik Router, Fiber ONT & a Wi-Fi 6 Router all powered by an old UPS I got off gumtree for a bargain, just by replacing its dated lead-acid battery with one of our Lithium batteries.

When the battery was put in the UPS it had a voltage reading of 13.45 volts, after running the Synology NAS at full power with 2 x 4TB harddrives for more than 2 hours, the voltage reading on the batteries was 12.64 volts, which means this set up should power our NAS for more than 3 hours.

If you cannot afford an Inverter Trolly or one of the DC to DC Inverters on Takealot, I highly recommend this cost-effective measure to power your internet. Especially useful if you have a UPS that takes two batteries.

If you do not have an old UPS laying around, ask your company for their old stock or look on Facebook Marketplace, people throw these units away because they think when the battery is dead it is no longer useful ( which in the days of lead-acid that was true, UPSes was not great at best ), which is not the case with the invention of these small factor drop-in replacement batteries designed to be used in hardware that used to run lead-acid.

Put new life into your old equipment, and make them more relevant today with loadshedding than ever before.

We do stock the 7Ah battery mentioned above if you are interested in doing the same conversion on your UPS. If you do not want to fiddle ( although this is straightforward), you can look at buying the all-in-one inverter which will power your TV during loadshedding.

Featured products