In this article I have explained a couple of inverter circuits featuring an automatic feedback control for ensuring that the output does not exceed the normal specified AC output level, and also does not exceed the specified overload conditions.
What is Feedback Control in Inverters
A feedback control in inverter is generally incorporated to control the output voltage and output current and prevent it from exceeding beyond dangerous limits.
In this system, the output AC mains voltage is first dropped to a proportionately lower level, and fed to the shut down pin of the control IC. The stepped down feedback voltage now follows the output AC and varies up/down accordingly, in a proportionate manner.
The control ICs shut down circuitry comares and monitors this feedback signal with a fixed ference derived from the battery volatge of the inverter.
In an event that the output voltage tends to rise above the predetermined value, and increase beyond the reference level, it activates the error amplifier, which shuts down the inverter output PWM. Once this happens, the output voltage instantly dips, causing the feedback signal to decrease below the reference value. This situation prompts the shut down feature of the IC to get disabled, and the IC starts working normally again.
If the output yet again tries to rise beyond the unsafe level, the above process is repeated in the identical manner, and this goes on continuously and rapidly, ensuring that the output voltage is never allowed to surpass the specified unsafe level.
Feedback Control in SG2524/SG3524/SG3525 Inverters
The first example circuit belw shows how an automatic feedback control can be added to a SG2524 inverter circuit. The same concept can be also applied to all the other inverter versions, using the IC SG3524, and SG3525.
You can refer to the following two datasheets for exactly knowing how the pinouts of the IC SG2524 IC are designed to function:
The feedback control loop is configured in the following can be understood with the following points:
The 220V AC output is first rectified using a 4 diode bridge rectifier circuit.
The rectified high voltage DC is dropped to a lower DC level, at around 5V to 10V through the voltage divider network built using the 220K resistors and the 10K preset.
The 10K preset is used to adjust the feedback voltage until the output voltage is controlled just at the right level.
The feedback is taken from the 10K preset's center arm and fed to the error amplifier's non-inverting input pin#1 of the IC 2524.
This error amplifier is nothing but an opamp set internal to the IC for controlling the PWM of the output pin#11 and Pin#14.
The inverting or the (+) input pin#2 of the op amp is clamped at a fixed reference level of +2.5V through the couple of voltage divider resistors configured around the pin#2 and pin#16 of the IC. The +5V reference potential is derived from pin#16 of the IC and then dropped to 2.5V using the two voltage divider resisters.
Since the pin#2 of the error amplifier is fixed at 2.5V reference, means that if the pin#1 of the opamp rises above the 2.5V level would instantly trigger the PWM feature of the IC, causing narrowing of the output PWM to the transistors.
The feedback 10k preset is adjusted in a such a way that feedback voltage at pin#1 reaches the 2.6 V mark as soon as the output voltage reaches the specified unsafe high voltage level.
In such situations, when the pin#1 receives a 2.6 V, it will cause the internal error amp to activate, narrowing the output PWMs to the transistors, which will in turn cause the output voltage to reduce to the safe lower levels, appropriately.
Adding Feedback in IC 555 Inverter
You might have already gone through the post which explains how to build simple 555 based inverters.
Although all these inverters are decently designed and will produce the intended 220 V or 120 V from an easy IC 555 set up, these do not have a built-in feedback system for ensuring a constant output voltage.
The following figure shows how an ordinary IC 555 inverter could be transformed into an enhanced inverter through an easy feedback loop control network.
In this circuit also, we find that the 220V output from the transformer is first rectified to a DC level, and then it is stepped down through a resistive network comprising of a 220K resistor and a 10k preset.
The 10k preset center lead is configured with the NPN transistor BC547, whose collector can be seen connected with the pin#5 of the IC which is control input of the IC.
We know that normally when pin#5 is open, the PWM at the output pin#3 of the IC has a maximum PWM, however, as the potential at pin#5 is reduced, the output PWM also gets reduced proportionately.
Grounding the pin#5 causes the output PWM at pin#3 to become very narrow, with almost zero average voltage at this pinout.
In the IC 555 feedback circuit, when the output voltage tends to rise above the unsafe high voltage threshold, as per the setting of the 10k preset, the base of the BC547 slowly starts getting biased. When this happens, the BC547 begins conducting and causes the pin#5 of the IC to get gradually grounded. The grounding of the pin#5 of the IC causes the output PWM at pin#3 to get narrower, which in turns causes the output voltage to drop to the normal levels.
Art says
Hay me again looking for my last post found this topic on feedback circuit. Well first off the two boost converters work great paralleled I used , 2x. .
0.1 ohm 10-watt resisters one on each positive leg. When I got to about 2000 watts they got very hot. I guess that’s ok since that is why I used 10 watts. I also saw that a diode was used instead of the resister, could you explain the difference and in my case it would have to be a big diode of high current. I also saw your feedback circuit, going to put that to use. Thank you have the best web site, you cover everything, no need to go any place else.
ART
Swagatam says
Thanks for updating the results. Glad the idea is working for you.
You last comment was posted under this article:
https://www.homemade-circuits.com/inverter-circuit-with-feedback-control/
Can you please tell me where is the diode placed in your boost converter circuit?
The function of the diodes could be to provide isolation across the outputs of the two boost converters.
You are most welcome, I am always happy to help!
Barry says
Hi senior Swagatam, I’ve been following your post for years. My question is, can a square wave inverter power a submersive pump machine? I’ve made one of your circuit using SG3525 3kv. I recoil the transformer 48 0 48. I used 48v battery. Everything worked fine but the transformer is overheating. The output MOSFETs, I used 6 pairs (12pcs) of irf260n
Swagatam says
Thank you so much Barry, for being a dedicated reader of this blog.
An appropriately rated square wave inverter can power a submersive pump motor, but the motor might make a lot of noise and heat up.
So you have to make sure your inverter is at least a modified sine wave inverter with a capacitor filter at the secondary side of the inverter transformer.
Here is an example design which you can effectively employ for the same;
https://www.homemade-circuits.com/wp-content/uploads/2022/04/1kva-inverter-circuit.jpg
You can change the transformer specifications accordingly to improve power efficiency.
Titus says
good day boss, please can you share the circuit you used?
Soplox says
Can this circuit withstand refrigerator
Swagatam says
That will depend on the transformer, MOSFET and battery capacities.
MOSES says
Please what changes can be done to convert and ordinary square wave inverter to modified sine wave
Swagatam says
You will have insert a 40% deadtime to convert the square wave into modified sinewave.
MOSES says
How do I achieve it with sg3525 inverter driver you posted in this forum. Please suggest a schematics to achieve that the pwm ic above.
Swagatam says
You can add a deadtime capacitor in the circuit and experiment with its value until a perfect modified waveform is achieved.
Elisius says
Mr Swatagam, thanks for your kind explanations on the two circuits. Please, the inverter circuits with 555 timer ic and 3524ic. How can I replace those transistors with MOSFETs?
I would like to see the diagrams of the two.
Thanks.
You can send it to my mail.
Swagatam says
Hi Elisius, I cannot find the circuit that you are referring to, please provide me the link, so that I can check it out.
Elisius says
https://www.homemade-circuits.com/wp-content/uploads/2021/05/555-inverter-with-feedback-control-compressed-768×404.jpg
This is the link. But I later found where you posted.
Thanks.
Please, I have another request. I need these inverter circuit to be configured to have feedback.
https://www.google.com/url?q=https://www.homemade-circuits.com/wp-content/uploads/2013/06/IC4047invertercircuit.jpg&opi=89978449&sa=U&ved=0ahUKEwjXpveU2-uBAxWYXUEAHepeD8MQ5hMIBQ&usg=AOvVaw2v7gUQy60lxU0N4f8bG6pa
Swagatam says
You can replace the the BJTs with MOSFETs in the 555 circuit, just make sure to replace the 1K gate resistors with 100 ohms.
For the feedback you can use the same feedback network which is shown for the 555 circuit. The collector of the BC547 must go to the pin#1 of the 4047 IC.
Malcolm Chose says
Hi,
I’m a beginner in need of your assistance with a simple PCB design for a Fan powered and ATX Inverter silent
electromagnetic generator proto… I only am left with a picture of the generator in question and electronics professionals may quickly figure out the wiring map of such a picture of the generator. In short, I need help with the schematic layout and can get started in my home workshop asap.
Swagatam says
Hi, I wish I could help you, however, sorry, it may be difficult for me to solve your generator wiring problem, because my expertise is restricted to circuit diagrams and schematics only.
Ngolobe Francis says
Please help me know how to practically build a working igbt welding inverter especially the inverter section and the output section.I understand the theory but how to do it is the problem.Thank you.
Swagatam says
IGBT welding circuit is a very complex design, it cannot be explained through comments. You can refer to the following post for a related article:
https://www.homemade-circuits.com/smps-welding-inverter-circuit/
nnakwuziechinonso@gmail.com says
How can I add more mosfet to ag3524 or tip to this inverter sg3524 for more output watts
Swagatam says
You can read the following article for more information regarding how to upgrade the power output of an inverter,:
https://www.homemade-circuits.com/upgrading-low-power-inverter-to-high/
nnakwuziechinonso@gmail.com says
Please who can help me with this with this inverter I tried many times and I failed who can guide me to make it work
Swagatam says
The above circuit was taken from the datasheet of the IC 3524, so it cannot be wrong.
If you build the circuit without understanding, then you can never succeed. You will have to understand and build the circuit step-wise, only then you can troubleshoot the faults and ultimately succeed, otherwise you will keep struggling.
nnakwuziechinonso@gmail.com says
How many voltage of 100nf and 10nf and 1nf capacitor can I use
Swagatam says
All should be 50 V or above….normally nF and pF capacitors are all 50V by default
nnakwuziechinonso@gmail.com says
Can I use SG3524 to replace sg2524
Swagatam says
Yes you can…
nnakwuziechinonso@gmail.com says
Can this inverter give me constant output watts
Swagatam says
Yes, as long as the battery is not over loaded.
nnakwuziechinonso@gmail.com says
0.001uf =100pf
0.01=10nf is it correct
Swagatam says
Use the following calculator:
https://www.digikey.in/en/resources/conversion-calculators/conversion-calculator-capacitance
nnakwuziechinonso@gmail.com says
Sir 0.1uf and 0.01uf and 0.001uf and 0.1ohm is not in market what can I use replace it
Swagatam says
These values are actually very standard values, you cannot replace them with other values….
nnakwuziechinonso@gmail.com says
Is those uf the same with 100nf
Swagatam says
yes, 100 nF = 0.1 uF
nnakwuziechinonso@gmail.com says
How many watts of resistor can I use
Swagatam says
All are 1/4 watt 5% CFR
nnakwuziechinonso@gmail.com says
Can I use 12volt battery 7amp on the first inverter.
Swagatam says
Yes you can….
nnakwuziechinonso@gmail.com says
Please can I use UPS transformer
Swagatam says
Yes you can…
Mohan says
I am looking for an inverter LED circuit (not an emergency light circuit), curious after seeing Philips Inverter LED bulb 9W or 12W, which glows on mains if power is there, else switches to Li-ion battery mode. Thanks.
Swagatam says
I haven’t yet designed it….. I will try to design it if possible and let you know.
souvik says
is it possible to make a 50hz inverter using atmega8 ic ?? and if possible can you make one???
Swagatam says
It is definitely possible, but my Atmega coding knowledge is not good, so I cannot make it.
Alwin cecil says
Sir for the above circuit 2v truck battery is used, will the same circuit with same components work for 12V 35Ah battery
Swagatam says
Hi Alwin, yes the circuit can work with 12V also, just make sure to use a 9-0-9V transformer for a 12V operation.
IGBINOBA ERERE says
Hello sir ,pls is it safe to connect the output of the bridge rectifier to your circuit directly without the use of a capacitor? As you did not use one in your diagram.
Then, if voltage at transformer tends to increase, does the output voltage of the diode rectified increases too?
Swagatam says
Hello Igbinoba, Actually a small value capacitor should be connected with the feedback bridge rectifier. You can add a 10uF/400V capacitor with the bridge outputs. Yes the bridge output will increase when the inverter voltage increases and vice versa.
Hillary says
good day swagatam. I am faced with construction of automatic voltage regulator (stabilizer) please do you have a circuit diagram for that
Swagatam says
Hi Hillary, here’s a simple stabilizer circuit which you can try:
https://www.homemade-circuits.com/how-to-make-small-homemade-automatic/
Hillary says
good day swag. thank for your reply and help so far, you are really doing a great work. my question is, the 5k resistors at the voltage divider stage of the opamp, can they be changed to 10k since I can’t get an exact value
Swagatam says
Thank you Hillary! You can use 4k7 for all those resistors
AYODELE PELUMI says
Please swagatam, I also a related issue with pic16f716 inverter module, it voltage feedback and as well as the current feedback. Can I get a diagram? Thanks sir
Swagatam says
Hi AYODELE,
Since I do not know the shut-down pinout details of the PIC16F, it can be difficult for me to solve your query.
alexandru says
Hi Swagatam. a diagram of the 12-230V inverter 4047 with feedback circuit, please. Thank you.
Swagatam says
Hi Alexandru, you can do it in this way:
Connect a bridge rectifier circuit at the output of the inverter.
Create a resistive divider across the positive/negative lines of the bridge rectifier, using a 220K resistor and a 100K preset.
Make sure to connect the 100K preset at the ground or the negative side of the bridge rectifier.
Take a BC547, connect its base with the wiper arm of the 100K preset.
Connect the emitter to the negative output of the bridge rectifier.
Connect the collector of the BC547 with the Ct pin of the IC 4047.
Make sure to connect the negative line of the bridge rectifier with the negative of the battery.
After this, adjust the 100K preset so that the inverter output voltage is unable to rise above a desired threshold such as above 220V etc
Alexandru says
thank you Swagatam for the prompt reply.
Swagatam says
You are welcome Alexandru!
Alexandru says
https://www.homemade-circuits.com/wp-content/uploads/2022/12/4047-100-watt-inverter-circuit.jpg Sir, what is the Ct pin on IC 4047, I don’t know. Pin 1 ; 2 or 3. Can you tell me please. This is the diagram of the inverter. Thank you. cd4047-100w-inverter-circuit-1/
Swagatam says
Pin#1 is the Ct pin of the 4047 IC
Alexandru says
thank you, sir
Aminu Ibrahim says
Hi sir
What is the work of latch in pulse with modulation?
Swagatam says
Not sure about it! I have not yet studied this concept!
Aminu Ibrahim says
Hi sir
I must thank you for giving beaginers like us a chance to interact based on what we don’t understand.
My question is, what is the voltage value I will get at pin 14 and pin 11 respectively if I use 24v as my vcc
Thnks
Swagatam says
Thank you Aminu.
You will get an average voltage of about 11V, and a peak voltage of around 24V on the output pins of the IC SG3535, when 24V is used as the supply input.
Aminu says
Thank you sir
Daniel says
Sir, am an electrical/electronic engineering student. Can you please direct me or help me with circuit diagram for wind turbine inverter, at least that can power 60watts bulb, charge a laptop and a mobile phone. Or maybe 100watt inverter for my
vertical axis wind turbine project
Swagatam says
Daniel, you can use any one of the circuits from the following article for your requirement. Just make sure the transformer is rated at 9-0-9V, 8 amp or 10 amp, and the windmill is able to supply around 12V with 7 t 8 amp current.
7 Simple Inverter Circuits you can Build at Home
Doug says
your site is extremely valuable to the DIY community!
Thanks for sharing this information.
I have a question about using a CT 220-110 output transformer for a “split phase” backup power supply for North America.
My question is this. if I use a CT 220v output transformer ie 220v output with 110v between L1 and CT, is it possible to load balance this arrangement?
If I’m not clear in my explanation, I can try and clarify.
Thanks
Doug
Swagatam says
Thank you very much and glad you found this site useful.
I think, yes it is possible to load balance the secondary side of the transformer to get two output phases and a single common neutral at the center
thocheerful says
Pls why my inverter always give me no feedback, and i try to rectify it most of time but yet same things.
Sir what is the ways out.
Swagatam says
Which circuit did you use?
evans says
Hello sir swagatam,iam into the full bridge type of inverter cause i use a small transformer for double power output. Please, can you tell how to connect this feedback to any diagram of a full bridge inverter using sg3524 of your choice that had discussed in one of your articles ,i would really appreciate. Show with a diagram for my quick understanding please,thanks.
Swagatam says
Hello Evans, for your full bridge inverter also you can apply the same feedback network which has been shown in the above article.
Anthony says
Also pls sir, how can I increase the wattage output
Swagatam says
You can read the following post for more info:
Calculate Battery, Transformer, MOSFET in Inverter
Anthony says
Ok , thanks sir, but sir how can I make it a pure sine wave
Swagatam says
You will have to create an SPWM circuit as I have explained below, and then integrate it with the transistor bases, or mosfet gates of the inverter
https://www.homemade-circuits.com/how-to-generate-sinewave-pwm/
Anthony says
Also sir what is the output wattage of the inverter diagram above using same ic sg2524. Thank you.
Swagatam says
wattage is 70 watts
Anthony says
Pls @ sir swagatam, is the inverter diagram above using sg2425 a pure sine wave or modified sine wave output inverter. Thanks for your reply
Swagatam says
Anthony, the circuit is square wave.
MARTINS says
HI MR SWAG, THANKS FOR UR PREVIOUS REPLYS I IT REALLY HELPED ME A LOT :
MY QUERY IS, IS IT POSSIBLE TO REDUCE THE VOLTAGE IN A CAPCITOR ,ie, IF I HAVE A CAPACITOR OF 50v 4700uf CAN I USE RESISTOR TO MAKE IT 25v 4700uf .
Swagatam says
You are welcome Martins, the capacitor voltage value determines it maximum holding capacity. If you supply 25V then the capacitor will store 25V, so it depends on how much voltage you are feeding to it.
And please do not in write capital letters.
MARTINS says
I MEAN IN THE PLACES U WROTE 1K RESISTOR DO U MEAN 100 ohm
Swagatam says
In the first diagram everything is correct, the shown 1K are also correct.
MARTINS says
HI SIR
THANKS FOR UR PREVIOUS REPLY
PLS AM A BIT CONFUSED ABOUT SOME ELECTRICAL PART PLS WHEN U WROTE 1K RESISTOR DID U MEAN 100ohm
(2)DID U HAVE AN ARTICLE DAT CAN POWER ELECTRIC IRON
Swagatam says
Hi Martins, please specify the comment reply which you are referring to?
All inverter circuits can be used for powering an electric iron provided they are upgraded as per the iron wattage..
MARTINS says
Hi sir
can i connect 470ohm + 100ohm resistor to use as 560ohm
Swagatam says
Sure, you can do that!
EBUKA says
GOOD DAY SIR
PLS DO U HV ANY ARTICLE OF AN INVERTER THAT CAN GIVE AN OUTPUT OF 7.5KVA AND HOW CAN INCREASE THE OUTPUT… THANKS IN ADVANCE, WAITING FOR UR REPLY
Swagatam says
Hello Ebuka, you can refer to the following articles for learning the procedures:
https://www.homemade-circuits.com/upgrading-low-power-inverter-to-high/
https://www.homemade-circuits.com/how-to-calculate-and-match-inverter/
Martins says
1-CAN MOSFET IRF3205 BE USED INSTEAD OF TRANSISTOR
2-HOW CAN INCREASE THE WATTAGE OF THE OUTPUT
Swagatam says
1) Yes it can be used.
2) Wattage can increased by implementing the steps explained in the following article:
https://www.homemade-circuits.com/upgrading-low-power-inverter-to-high/
Martins says
Good day mr swag
pls do u have any article
of how to make an inverter without using an ic and of about 50HZ-60HZ speed to switch on/off
Swagatam says
Hi Martin, you can try the following diagram:
https://www.homemade-circuits.com/how-to-make-simple-200-va-homemade/
Saiful Islam says
very nice article
LB STAR says
Thanks a lot sir. I was so impressed that you are helping us here and also responding swiftly and well. Thanks so much sir.
Swagatam says
You are welcome!
Godspower says
Thank you sir for the circuit. sir please please what is the frequency of the above circuit for sg3524 and Ic 555
Swagatam says
You are welcome Godspower, the frequencies should be around 50 Hz, but for the IC 555 you will have to tweak using the 100k preset.
Godspower says
Thank you sir for the quick response sir.
Please sir from the Sg3524 circuit above, i could not find the following resistors, 5k, 2k, 20k, please sir is it posible for me to replace 5k with 4k7? and connect (2) 1k in series and (2)10k in series to give me 2k and 20k repectively? Thank you sir God bless you sir.
Swagatam says
You are welcome Godspower, yes definitely all those options are possible, no problems with that.
Godspower says
Thank you so much sir very grateful
Seun says
Please how can I add low battery shutdown circuit to #10 to latch, the design I have personally cut off but comes up when the battery voltage rises
Swagatam says
You can add the following op amp design with the first circuit for the low battery cut off:
Seun says
Thanks Sir, please how can use this for 48v input
Swagatam says
Hi Seun, you can drop the voltage to 12V for powering the IC through a 4k7 1 watt resistor, and a 12V zener diode.
Seun says
Please sir, what adjustment can I do to work with 48v input.
Seun says
Thanks sir, please is there any alternative to using pin 16, the board is already plastered. Swagatam, help out
Swagatam says
Pin16 gives the 5V reference to the op amp, if you don’t want the reference from pin16, you can create it using an external 1K resistor, and a 5V zener diode.
Seun says
Thanks Sir for your assistance, I have tried both ways, they cut off but didn’t latch, any help.
Swagatam says
I guess it won’t latch, instead it will cause the output PWM to become minimal so that the battery usage becomes negligible for the load
Seun says
Please Sir, how can I have low battery cut that will shut down and latch for Sg3524 circuit
Swagatam says
Seun, you can use the following modification for latching the inverter during low battery voltage
Godspower says
Please sir the op amp low battery you posted in your comment section, 1. Sir please how can i adjust the cutt off voltage manually using the 10k preset without variable or bench power supply?
2. Is it the above circuit applicable to 12v system using Sg3524 ic.
Thanks for your response in advance.
Swagatam says
Godspower, you will need to feed the circuit supply lines with the low voltage at which you want the cut off to happen. Initially rotate the preset wiper upto the positive supply rail. Then switch ON the low voltage supply, and adjust the preset until the output of the op amp just turns high and the LED illuminates.
yes it is applicable to 12V supply
Godspower says
Mr Swag i am very greatful sir for this quick response God in heaven will continue to bless you.
please sir do not be annoyed because of my questions as i am an electronics hobbyist and i have built my inverter am currently using , please one more question sir.
I built my 12volt battery using lithium ion battery but no Bms, but base on my research i discovered that the maximum full voltage is 12.6v, now i want the battery to be discharged up to 9v since am personally using the battery. question sir
1. Is it possible to adjust the above circuit to cut off at 9v?
2. Advice me on the minimum voltage to discharge from the battery?
Swagatam says
Hello Godspower, you must adjust the preset for a 10V low battery cut off, meaning, if the supply reaches 10V, the opamp output will become high, and if the voltage increases above the 10V, for example if the voltage is 10.2V then the opamp output will become low.
eniola says
Hi sir, I want to add a low battery cut off at 11v, imitating your low battery cut off circuit.sir, I want to cut off at 11v and I think for it to cut off at 11v the pin 3 has to be set at a constant voltage of 11v and the pin 2 will be set at,let me use 12v,as the battery voltage get utilized the voltage at pin 2 start to drop on till it gets to 11v which will trigger the opamp output high.since the ic is employ as a comparator.im I right? If right please,just give me resistor value to implement that.or just give me the formula for voltage drop by resistor with the current.
Swagatam says
Eniola, that’s right, however instead of using fixed resistors you must use a preset at pin#2, so that the exact 11V cut off can be adjusted, as implemented in the SG3535 circuits:
https://www.homemade-circuits.com/sg3525-pure-sinewave-inverter-circuit/
Seun says
Thanks Swag for this article, but how can I incorporate the overload shutdown to my sg3524 module.
Swagatam says
Hi Seun, please see the pin4 and pin5 configuration with the 0.1 Ohm resistor. This resistor value decides the overload or over current shut down.
Seun says
Please sir, how do calculate the resistor per load
Swagatam says
You can use the following formula
R = 0.2 / Load current limit
eniola says
Sir, God bless you for really coming up to each of my questions.please sir, I have some few questions which are:1 the above sg2524 inverter circuit,at the output, do you need to filter out the ripple signal? Because is not a smooth dc output, and if yes then what value? secondly,I want to cut off for my inverter at a power rating of 1000w,due to the formula in some of your feedback to bro.seun.sir,I calculated it and it was R=0.0024,am using 12v battery and load current of 83.3amp.so how many 0.1ohm resistor do I need a connect in parallel? thanks sir.
Swagatam says
Thanks Eniola, to tackle the ripple you can add a 2200uF capacitor right across the battery terminals, and also a 100uf right across the IC supply pins.
For calculating the number of 0.1 ohm resistors you can use a parallel resistor formula….please use the formula or you can try any online resistor calculator software to get the approximate value of the resistors.
eniola says
Please sir, how can I calculate the resistor in parallel? Or is it 1/R=1/r1+1/r2+1/r3…… orJust give me the formula sir. But if it is the above formula ostensibly,I will parallel about 10 of 0.1ohm resistor for 1000w cut off.but if not just introduce me the appropriate formula.thanks sir, looking forward to your quick reply
Swagatam says
Eniola, you can use the mentioned formula for calculating the number of parallel resistors with some manipulation. You can put 0.1 for R1, R2, R3…and check how many resistors are required to get close 0.0024…then further use the result with the parallel formula to get the precise value.
You can online calculators also
Anthony says
Hello sir, pls the above sg2524 circuit above
1. What is the wave form output, if it’s square wave, how can we improve it to modified sine wave or pure sine wave
2. What is the wattage output, what components should we add to improve the wattage to 1000watts
3. Pls sir, where is the input side in the circuit, i.e the 12v plus and minus side.
4. Lastly sir, which battery volts does it use. 12v or 24 volts
Thanks very much sir for answering.
Swagatam says
Hello Anthony, the output of any inverter will be always square wave unless an SPWM concept is employed.
The wattage will always depend on transformer, and battery ratings, and also the mosfet. You will have to upgrade it accordingly. I think I have explained you regarding this in one of the earlier comments.
The battery supply must be connected across the transformer center tap, and the common emitter points of the transistors.
It can be used with a 12V or a 24V battery.
Carlos says
Hello, No sir, I used the number 1
Swagatam says
Carlos, you can try the the following modification for the feedback control
Carlos says
Hello sir Swagatam good afternoon. I have a circuit inverter from his website, the circuit is modified sine wave with lm555 timer and cd4017. The question is.. How can I add to that circuit this circuit with feedback control. Thanks you so much
Swagatam says
Hello Carlos, is the diagram from the following article:
https://www.homemade-circuits.com/modified-sine-wave-inverter-circuit-2/
did you use the second diagram??
Evans says
Good job sir,your unrelenting effort is of great help to us.
Swagatam says
It is my pleasure Evans!
Art Zacchia says
Hay it’s me again. After blowing 4 egs002 and who knows at least 40 MOSFETs, I am done with the egs002. You have provided all the circuits that are needed to make the inverter that I want to build. It’s going to be a pure sign wave operating at 170 volts DC to produce about 115 volts AC. I liked the formula 1.41 I was using.707 I know it’s about the same. Anyway. You are the only one I have found who takes the time to work with us guys and nobody can answer the questions about that egs002. I don’t want to ask too many questions right now let me get something built. But real quick when I use the voltage feedback everyone is saying to use a 200k resistor. That’s for a 220-volt output would i use a 100k since my output voltage is 115 volts I may go higher to 125 volt AC max with a 175 volt DC battery pack. I have a friend that has a business in lead acid batteries he give me them for free. You should see this battery pack that i made. So there is no need for me to go with a transformer. Thanks for your time.
Swagatam says
Thanks Art, I am sorry to hear about your problems with EGS002
Actually I have never used this module practically so I won’t be able to suggest much on this. I wish I could.
The feedback line has a 220K resistor in my above circuit. I have connected the 220K resistor in series with the 10k preset.
I hope you build and succeed with tbis project soon
All the best to you!
Art zacchia says
Everything that I have built from you has worked, so don’t see why your schematics will fail me. So what you are saying is it doesn’t matter whether the feedback voltage is 120 volts or 220 volts right, I am going to build what your schematics tell me to use. I also found your article on how MOSFETs work I read it once I will read it 10 times more if I have to. A lot of engineers have blogs like yours you go into depth about the circuit and you answer all the questions people ask of you. its very help full. Thanks, I will get started will be in touch.
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Swagatam says
Thank you very much, and glad my circuits worked for you. Yes whether 120V, or 220V, you can use the 220K series resistor. I appreciate your kind thoughts