A relatively simple 1000 watt pure sine wave inverter circuit is explained here using a signal amplifier and a power transformer.
As can be seen in the first diagram below, the configuration is a simple mosfet based designed for amplifying current at +/-60 volts such that the connected transformer corresponds to generate the required 1kva output.
UPDATE:
There's a much easier and efficient way of making a 1 kva inverter circuit using the following 4017 PWM version circuit. Since the PWM is created directly through the 4017 output, the PWMs are much accurate and the waveform is uniform and does not depend on any external adjustments.
The biggest advantage of using this circuit is that the output can be modified to almost a pure sine wave by adding a few PPC capacitors across the transformer output.
Here' the circuit which you can try:
Parts List
- Resistors
- All resistors are 1/4 watt 5% unless specified
- 100K = 2nos
- 100 ohm 1 watt = 1no
- 1K = 2no
- 10 ohm = 2no
- Capacitors
- 0.047uF ceramic or PPC = 1no
- 10nF ceramic or PPC = 1no
- 10uF/25V Electrolytic = 1no
- Semiconductors
- 1N4148 diodes = 7nos
- 12V/1 watt zener diode = 1no
- IRF3205 MOSFETs = 10nos
- Transformer 12-0-12V/220V/1kva
- Battery = 24V/500 Ah = 1no
The previous original article which is continued in the following paragraphs also discusses a 1000 watt inverter circuit, however, this circuit being a linear amplifier is not so efficient, and may result in a lot of dissipation.
I would recommend trying the above circuit, which will give you a 100% results quickly.
Remember, you must first try and confirm the working of the inverter using single MOSFETs on each channel. Once the working is confirmed then you can add more number of MOSFETs in parallel to upgrade the power capacity of the inverter to 1000 watts
Circuit Operation
Q1, Q2 forms the initial differential amplifier stage which appropriately raises the 1vpp sine signal at its input to a level which becomes suitable for initiating the driver stage made up of Q3, Q4, Q5.
This stage further raises the voltage such that it becomes sufficient for driving the mosfets.
The mosfets are also formed in the push pull format, which effectively shuffles the entire 60 volts across the transformer windings 50 times per second such that the output of the transformer generates the intended 1000 watts AC at the mains level.
Each pair is responsible for handling 100 watts of output, together all the 10 pairs dump 1000 watts into the transformer.
For acquiring the intended pure sine wave output, a suitable sine input is required which is fulfilled with the help of a simple sine wave generator circuit.
It is made up of a couple of opamps and a few other passive parts. It must be operated with voltages between 5 and 12. This voltage should be suitably derived from one of the batteries which are being incorporated for driving the inverter circuit.
The inverter is driven with voltages of +/-60 volts that amounts to 120 V DC.
This huge voltage level is obtained by putting 10 nos. of 12 volt batteries in series.
The Sinewave Generator Circuit
The below given diagram shows a simple sine wave generator circuit which may be used for driving the above inverter circuit, however since the output from this generator is exponential by nature, might cause a lot of heating of the mosfets.
A better option would be to incorporate a PWM based circuit which would supply the above circuit with appropriately optimized PWM pulses equivalent to a standard sine signal.
The PWM circuit utilizing the IC555 has also been referred in the next diagram, which may be used for triggering the above 1000 watt inverter circuit.
Parts List for the sine generator circuit
All resistors are 1/8 watts, 1%, MFR
R1 = 14K3 (12K1 for 60Hz),
R2, R3, R4, R7, R8 = 1K,
R5, R6 = 2K2 (1K9 for 60Hz),
R9 = 20K
C1, C2 = 1µF, TANT.
C3 = 2µF, TANT (TWO 1µF IN PARALLEL)
C4, C6, C7 = 2µ2/25V,
C5 = 100µ/50v,
C8 = 22µF/25V
A1, A2 = TL 072
Part List for Inverter
Q1, Q2 = BC556
Q3 = BD140
Q4, Q5 = BD139
All N-channel mosfet are = K1058
All P-channel mosfets are = J162
Transformer = 0-60V/1000 watts/output 110/220volts 50Hz/60Hz
The proposed 1 kva inverter discussed in the above sections can be much streamlined and reduced in size as given in the following design:
How to Connect Batteries
The diagram also shows the method of connecting the battery, and the supply connections for the sine wave or the PWM oscillator stages.
Here just four mosfets have been used which could be IRF4905 for the p-channel, and IRF2907 for n-channel.
Complete 1 kva inverter circuit design with 50 Hz sine oscillator
In the above section we have learned a full bridge design in which two batteries are involved for accomplishing the required 1kva output. Now let's investigate how a full bridge design could be constructed using 4 N channel mosfet and using a single battery.
The following section shows how a full-bridge 1 KVA inverter circuit can be built using, without incorporating complicated high side driver networks or chips.
Using Arduino
The above explained 1kva sinewave inverter circuit can be also driven through an Arduino for achieving almost a prefect sinewave output.
The complete Arduino based circuit diagram can be seen below:
Program Code is given below:
//code modified for improvement from http://forum.arduino.cc/index.php?topic=8563.0
//connect pin 9 -> 10k Ohm + (series with)100nF ceramic cap -> GND, tap the sinewave signal from the point at between the resistor and cap.
float wav1[3];//0 frequency, 1 unscaled amplitude, 2 is final amplitude
int average;
const int Pin = 9;
float time;
float percentage;
float templitude;
float offset = 2.5; // default value 2.5 volt as operating range voltage is 0~5V
float minOutputScale = 0.0;
float maxOutputScale = 5.0;
const int resolution = 1; //this determines the update speed. A lower number means a higher refresh rate.
const float pi = 3.14159;
void setup() {
wav1[0] = 50; //frequency of the sine wave
wav1[1] = 2.5; // 0V - 2.5V amplitude (Max amplitude + offset) value must not exceed the "maxOutputScale"
TCCR1B = TCCR1B & 0b11111000 | 1;//set timer 1B (pin 9) to 31250khz
pinMode(Pin, OUTPUT);
//Serial.begin(115200);//this is for debugging
}
void loop() {
time = micros()% 1000000;
percentage = time / 1000000;
templitude = sin(((percentage) * wav1[0]) * 2 * pi);
wav1[2] = (templitude * wav1[1]) + offset; //shift the origin of sinewave with offset.
average = mapf(wav1[2],minOutputScale,maxOutputScale,0,255);
analogWrite(9, average);//set output "voltage"
delayMicroseconds(resolution);//this is to give the micro time to set the "voltage"
}
// function to map float number with integer scale - courtesy of other developers.
long mapf(float x, float in_min, float in_max, long out_min, long out_max)
{
return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
}
The Full-Bridge Inverter Concept
Driving a full bridge mosfet network having 4 N-channel mosfets is never easy, rather it calls for reasonably complex circuitry involving complex high side driver networks.
If you study the following circuit which has been developed by me, you will discover that after all it's not that difficult to design such networks and can be done even with ordinary components.
We will study the concept with the help of the shown circuit diagram which is in the form of a modified 1 kva inverter circuit employing 4 N-channel mosfets.
As we all know, when 4 N-channel mosfets are involved in an H-bridge network, a bootstrapping network becomes imperative for driving the high side or the upper two mosfets whose drains are connected to the high side or the battery (+) or the positive of the given supply.
In the proposed design, the bootstrapping network is formed with the help of six NOT gates and a few other passive components.
The output of the NOT gates which are configured as buffers generate voltage twice that of the supply range, meaning if the supply is 12V, the NOT gate outputs generate around 22V.
This stepped up voltage is applied to the gates of the high side mosfets via the emitter pinouts of two respective NPN transistors.
Since these transistors must be switched in such a way that diagonally opposite mosfets conduct at a time while the the diagonally paired mosfets at the two arms of the bridge conduct alternately.
This function is effectively handled by the sequential output high generator IC 4017, which is technically called Johnson divide by 10 counter/divider IC.
The Bootstrapping Network
The driving frequency for the above IC is derived from the bootstrapping network itself just to avoid the need of an external oscillator stage.
The frequency of the bootstrapping network should be adjusted such that the output frequency of the transformer gets optimized to the required degree of 50 or 60 Hz, as per the required specs.
While sequencing, the outputs of the IC 4017 trigger the connected mosfets appropriately producing the required push-pull effect on the attached transformer winding which activates the inverter functioning.
The PNP transistor which can be witnessed attached with the NPN transistors make sure that the gate capacitance of the mosfets are effectively discharged in the course of the action for enabling efficient functioning of the entire system.
The pinout connections to the mosfets can be altered and changed as per individual preferences, this might also require the involvement of the reset pin#15 connection.
Waveform Images
The above design was tested and verified by Mr. Robin Peter one of the avid hobbyists and contributor to this blog, the following waveform images were recorded by him during the testing process.
for how long can it run using 24v?
can it run refrigerator and TV set at same time?
kindly help me with diagram that use mosfet 1010
To run a TV set and a refrigerator together, you might need to upgrade inverter design to 2000 watts minimum.
dear, friend I want making a Solar invertor 5 Kw 24 volt without battery. Please help me thanks,
Hello Abdul, with 24V, your solar panel will need to be rated at 5000/24 = 208 amps, which looks impracticable…
Hello! I know I’d already asked this circuit or subject 7 months ago but I revisited it today and I would to like ask again. The second circuit diagram that using sine generator circuit, is it pure sinewave circuit?
Yes, it is a pure sine wave inverter but the efficiency will be low due to high heat dissipation.
I’m interested buiding a power inverter and I like sinewave because of its nature that most elctronic devices it can be use. But on the other hand, I also read your modified sinewave 500 watts as well. Maybe I will just build latter first. In terms of effiecient, which is better the 1K sinewave or 500 watts modified?
Which 500 watt modified inverter are you referring to? Please provide the link of that article.
Can I use above H bridge ckt. for 24 v , 600Khz ?
I would recommend using the following circuit with the 4017 outputs, because it is much simpler.
https://www.homemade-circuits.com/wp-content/uploads/2017/03/sg3525-3.png
You can use 24V 600kHz with the above circuit.
Hey, I am new. In the Arduino based circuit diagram, I need only a 120 volt AC output. 220 is not required. What change can be done? Would really like to try this.
Hey Kerry, For 120V output you just have to use a transformer whose secondary winding is rated to produce 120V instead of 220V.
Thanks Swagatam. Do you know if there is a clearer drawing of the circuit somewhere?
No problem Kerry. I have an Arduino inverter article as given below. In this diagram you just have to replace the transformer with a 6-0-6V primary and 120V secondary winding. That’s all. If you this you will be able to get the required 120V from the inverter.
https://www.homemade-circuits.com/arduino-pure-sine-wave-inverter-circuit/
On the first schematic above. Is it modified sinewave or pure sinewave? cause on the diagram where in the transformer output there is “pure sinewave” written on it.
The first circuit will produce almost a pure sinewave AC once the 3uF output capacitor is connected.
Hello sir, i really appreciate the help you are rendering.
How can i use egs002 pure sine wave mosfet driver in the above circuit?
Hello Olusegun,
The EGS002 is itself a sine wave inverter module which can be configured with external mosfets for high power output. For the circuit diagram you can refer to the following article:
https://www.homemade-circuits.com/egs002-datasheet-circuit-diagram-explained/
Sir please. if I need any amount of power of my desire all I have to do is to keep increasing the BATTERY, the TRANSFORMER and RESISTOR Living the MOSFET the way it is ?
Yes that’s correct…but MOSFETs may also be required to be upgraded. However since the first design already has many high power mosfets connected in parallel, they won’t require an upgrade for 3000 watts.
Calculate Battery, Transformer, MOSFET in Inverter
With the diagram in this Article, it means it can take up to 3,000 watt without upgrading the recommended MOSFET already used in this Article… Is that correct?
I think you are referring to the IRF3205 msofets, yes that’s correct, if the mosfets are connected with large heatsinks and the battery voltage is around 48 V.
Sir please how can I increase the power to 3000w on the first diagram
Samuel, It can be done by using a 48 V 300 Ah battery, 24-0-24V 150 amp transformer. Change the 100 ohm 1 watt to 1K 2 watt
Thank you sir for answering my previous question Please can i use it to power my television and refrigerator.
Yes you can use it.
Sir please in that first article if I use 4 mosfet and 6v 50amp transformer with 12v 45ah can i get 1500watt
Hi John,
For getting 1500 watt a much bigger battery will be required. It should rated as follows:
1500 / 12 = 125 amps. 125 amps will be the discharge rate per hour. So if 5 hour back up is required, the battery will need to be 125 x 5 = 750 Ah
Can I use your circuit diagram to make same productions ?
Yes you can use them for production.
How many mosfets will I add in each channel to get 2kva at 12v/200ah battery
You can add 5 nos of IRF3205 on each channel
Hello Sir.
Good day,inverter will remain among the focus among your projects.i saw an Arnduino,5v dc to ac spwm board in an online retailer with 17 pins. I didnt know much about Arduino.My question is how can i inco-orperate it to an inverter circuit,,,that is pin connections..Is it good for me to use a 24v supply for the inverter and 5v for the Arduino board.
Another question is …these online cheap china inverters,are they good.Does their template match with their output.
Thank you so much.
Thank you Patrick,
You can feed the SPWM from the Arduino into the base of transistor drivers to drive the transformer with the SPWM.
Yes 24V is better than 12V since higher voltage means lower current which in turns helps to keep the transformer size smaller and generate lower amount of heat on the mosfets.
I have never used a Chinese inverter so I am not sure how good they are. You can confirm it only after a practical testing.
You can get more information regarding how to interface SPWM Arduino with transistors in the following link:
Arduino Pure Sine Wave Inverter Circuit with Full Program Code
Hello.
It’s a nice job! I like simple decisions of difficult task! I’m sorry, but I want to ask here you one stuff. Did you ever designed high power buck 220DC-120AC pure wave 60Hz? I’m working on this project for my home. I would like to get some fresh idea. If yes, let me know please. Thank you.
Hi, thank you! you can see the following article, it explains a non-isolated 220V to 12 V buck converter circuit
https://www.homemade-circuits.com/simple-220v-smps-buck-converter-circuit/
hello there, i wasw wondering as in the first section u staged 10 pairs of the bridge to get the 1000watts hence 1kva but in the lower figures where us showed “full 1 kva circuit” there were only 4 of them 200watts i can guess. is it on purpose to shorten the image size or is it actually just 4 of them?
Hello, if you use two 50 amp MOSFETs in parallel as shown in the last diagram, that can be sufficient to deliver 1000 watts of power at 24 V…therefore there’s actually no need of employing more than 2 mosfets per channel.
ah i get it. btw the MOSFETs that you have recommended don’t do more than 7A at 100watts. the datasheet by renesas (current distributors of the fet) any recommendation for the n and p channel mosfets that can do 50A?
Getting a 50 amp P channel mosfet looks difficult so better to go with 4 nos of IRF540, and IRF9540 each for achieving 1000 watts.
part availability would not be that big of a problem as a lot of it is available at Digikey India. the only issue I am having is the schema in=mages are too blurry and low res.
right click the image and open it in a new tab…the image is quite big and the part numbers are clearly visible. You can look for 50 amp 100V p-channel n-channel mosfets in shops
also those mosfets are obsolete now . especially 9540
Hi Mr Swagatam !
I read each one the questions people has sent to you and yours attentive answers. Congratulations on your exceptional patience and willingness to help! As a 72-yo retired technician (from valve time) I am taking the challenge of making an H bridge capable of sinusoidally supply 120Vrms @ 10A at 60Hz switchable to 120Vrms @ 10A at 1 to 4H ! over inductive load . Is it possible to achieve this using SG3525 or ,if not,could you suggest another way? To make things more difficult I must use single supply! Thanks in advance for your orientations .
Hi Mr. Oswaldo,
I am always happy to help and be attentive to dedicated readers like you! Thank you for stopping by and writing this question!
An SG3524 is actually a PWM IC which can be used for easily achieving constant outputs and over current protection features.
So if you want these features also in your inverter then SG3524 can be recommended, if not then the straightforward IC 4047 would be more suitable.
However, the main issues with an H-bridge is its rather complex working design, which calls for specialized driver H bridge ICs as I have explained below:
Simplest Full Bridge Inverter Circuit
The above links explains H bridge using Nchannel MOSFETs exclusively, which are supposed to be more efficient.
If a little lower efficiency is acceptable then an easier alternative can be tried using 2 P channel and 2 N channel MOSFETs, without involving complex driver ICs as given below:
Easy H-Bridge MOSFET Driver Module for Inverters and Motors
Hope this helps
Hi Mr Swagatam !
Since your answer I tried unsuccessfully to get sinusoidal shaped output using SG3525 ,then I saw a post looking for your guidance to build something similar to what I need .
“I have a 2012 & 2013 Prius, The Prius is unique in that it has a 200 VDC (nominal) high-voltage battery pack etc. etc ”
So I gave up on the SG3525 and set up the circuit with IRS2453 (took a long time to get then from China) exactly as shown in https://www.homemade-circuits.com/5kva-transformerless-inverter-circuit/. For the bridge 4 x IRGP4062D, RT 120K, CT 100K nf providing about 60Hz at IRS2453 pins 6/7. Frequency 5.5Khz, 50% dutty cicle at 741 pin 2 Vcc=50V.
I have been trying sleepless nights but no way to get sinusoidal output over the load for test(93R) even adding large amount of capacitors and / or increasing the inductance of the low-pass filter. Using 741 After 3 minutes low side IGBTs extremely hot (31,4Vrms@93R) .Replacing to LM383 , 27Vrms and everthing is cold ! . Sent diagram and scope photos to your email hopping you could help to find a solution .
Hi Mr. Oswaldo, you cannot build a complex inverter circuit by simply assembling the parts….you will have to understand each and every section of the design and then check them separately using an oscilloscope, and then finally integrate the stages to complete the project.
Before attempting the sinewave you must first successfully build the square wave version and then upgrade it to sine wave.
The following design will provide 100% sinewave you you build it step wise and correctly:
https://www.homemade-circuits.com/wp-content/uploads/2017/10/3000-watts.jpg
Bună dragul meu doresc să știu care este tensiunea de lucru în poarta tranzistorului Mosfet cît trebuie ca să lucreze 3v-5v -10v cevaloare este optimă casă nu se ardă tranzistorul am un montaj de invertor care se alimentează la tensiunea de 36v cam atît știu să explic mulțumesc .
The MOSFET gate voltage will keep varying according to the music level, from minimum to maximum supply voltage 60 V.
Since it is configured as a common drain amplifier, the gate source voltage will be always be between 7 and 10 V.
Sir, I am working on an H bridge sine wave inverter for 500W at 12V. I am able to convert the 12V DC battery to 12V AC at 50Hz doing open loop simulation. But when the load is connect the current is very low. How can I improve my power rating. Can you share reference material to design inverters with random power ratings at random voltages, like a generalised case.
Haizon, for 500 watt output, the current must be rated at 500 / 12 = 41 amps. Which means the battery must be rated at minimum 200 Ah capacity. So please simulate using a 12V 200 Ah battery
Sir how can we fix it as 200Ah. Can you please explain how to choose 200Ah.
Simulated using 200Ah battery Sir
Still the current at the output is 0.6A at 12V.
Simulation results are often not accurate, instead if you build and test your set up practically then I think you can accomplish the results correctly…
Manolis, yes you can use your mosfet amplifier for getting a pure sinewave AC output, by applying the input sine generator and 60V SMPS.
Sir, I have reead many article in electronic, and also from your site, and still yet am unable to start building circuit that are simple,
Pls sir how can I come over this challenges.
I will greatly appreciate your response sir.
Thanks in advance
It will take a lot of time and will require consistent reading and experimenting practically.