How to Make Inverter Without Transformer / DIY Transformerless Inverter

[Music] today i'm gonna show you how to make an inverter without using any transformer this inverter called transformerless inverter the traditional inverters that working with car batteries doing two tasks at the same time first increasing the low voltage of the battery to high voltage and the second converting the dc voltage to ac voltage however in some cases we don't need to increase the voltage for example let's say we have many solar panels connected together in series in this case the voltage level generated by solar panels is high enough so we don't need to increase the voltage anymore and since the transformers in the traditional inverters are responsible for increasing the voltage now we can remove the transformer and make a transformer-less inverter the only process that we need here is converting the high dc voltage to ac voltage with pure sine wave to do that we have to use four n channel mosfets and connect them together as shown here then we need a driver to switch on and off each two mosfets periodically here i am using this spwm driver board it is so cheap and easy to use this driver has a lot of features such as soft start controlling the cooling fan over voltage protection over temperature protection and so on you can buy this driver with a tiny display but i didn't this display can show you the voltage current temperature and the frequency in the datasheet of this driver board you can find how to connect the components together you just need a few resistors and diodes beside of the mosfets the inductor and capacitor used for filter out the spwm and convert it to pure sine wave this driver board needs two 12 volt and 5 volt power supply they must be isolated from the high input voltage that coming from the solar panels i used this tiny power supply the input voltage of this power supply is supposed to be ac voltage but it works just fine with high dc voltage i convert this circuit to pcb and order it from pcbway.com after 10 days i received it then i soldered the components on the pcb i tried to make this pcb 10 centimeters by 10 centimeters or even less because the pcb manufacturers usually ask you to pay more money if your pcb was bigger than 10 centimeters this is why i put the components very close to each other this is an inductor to filter out the output waveform it is not a transformer so we still can call this circuit transformer less i used exposed copper traces so i can solder them to make them handle much more current you have to use isolation pad between the mosfets and the heatsink since this circuit working with high voltage so i made a plastic enclosure for it by using my 3d printer i'm using a ferrite ring around the output wire to prevent rf interference so now it's time to test here i have 90 lithium ion batteries connected together in series the output voltage is more than 370 volt so it's so dangerous don't use lithium-ion batteries without bms or battery equalizer but i did that for few minutes just for this presentation by the way the high voltage battery is already available in the markets from such a big company like lg you need a dc circuit breaker here i'm using a 40 watt incandescent lamp as a load when i switched on the inverter the output voltage rises slowly this is called soft starts and it is a good feature the cooling fan stay off because the mosfets are cool by the way we have an ntc touching the heatsink to measure its temperature i test different loads to make sure the inverter working just fine now let's see how much is the efficiency of this inverter the efficiency is the output power divided by input power to make the measurement precise i disconnect the ac voltmeter because it wastes some power the power consumption of this incandescent lamp is 38.5 watts divide this number by input voltage times input current so the efficiency is 96.5 percent which is excellent as you can see here the output waveform is pure sine wave as i said before you can connect this inverter to solar panels if you need 220 volt ac your solar panels must generate at least 311 volt and if you need 110 volt ac your solar panels must generate at least 155 volt dc by using this potentiometer you can set the output voltage you need if you short out jumper number 5 the output frequency will be 50 hertz and if short out the jumper number 1 the output frequency will be 60 hertz you can read more about them in the datasheet it is so important to connect the proper fuse between the inverter and your high voltage battery or solar panels maybe you wondering how much is the maximum power of this inverter it depends on your mosfets but keep in your mind that this circuit has a resistor as current sensor according to this data sheet when the voltage across this resistor become more than 0.5 volt the over current to protection activate the value of this resistor in this circuit is 0.1 ohm so according to ohm's law the maximum current could be 5 amps which is 1.1 kilowatts let's see what happen if i try to run in a load with power consumption more than 1.1 kilowatt this water boiler consume 1.5 kilowatt as you can see here the driver board decreasing the output voltage as an overload protection if you need more power you have to use a current shunt resistor with lower value and the proper mosfets that can handle that much current please like this video and subscribe to my channel thanks for watching [Music] you

Channel: Mousa - Simple Projects

Views: 34,214

Keywords: How to Make Inverter Without Transformer / DIY Transformerless Inverter, EGS002, SPWM, INVERTER, pure sine wave, transformer

Id: 4dB0Mlr81tA

Length: 7min 0sec (420 seconds)

Published: Thu Apr 14 2022