This simple and cheap(but powerful) squarewave oscillator can give oscillation to any mosfet based inverter/ups.
The circuit consists of one central I.C CD4047. I used HCF4047BE from ST microelectronics. This is an improved version of circuit spread over the internet of inverter by I.C 4047.
This circuit is the first part of the Inverter project.
This circuit has more efficiency than that one. Here the MOSFET does not gets hot easily, and the Diodes IN4148 provides protection of the circuit in case of MOSFET leakage. A LED is added for easy diagnostics.
Veroboard design of the circuit is given also, as we know, making PCBs is another dedicated work and we cannot make it in hurry. Inspite of that, veroboard gives same functionality in lesser time(though size becomes a little big.)
But if you want to make PCB for this, follow my PCB making guide .
Parts List:
| IC | CD4047 | 1 |
| Capacitor | 0.01uF or 103 | 1 |
| Potentiometer | 100K | 1 |
| Resistor | 220 Ohm | 4 |
| Resistor | 10k Ohm | 2 |
| Resistor | 330k Ohm | 1 |
| LED | Red | 1 |
Thanks for this…and yeah veroboard suits well for these simple projects…keep writing buddy
dear arup,
i tried to design this circuits but i have replaced 3055 npn transister to N-channel IRF540 Mosfet,i have attached DVM on 220vac output of tranformer,it display only 20 volts,this point to be also noted that 1 mosfet also too hot & 2nd one is normal cool,i have sent the circuit diagram on your gmail add,plz chech it,n tell me how does it work normally.
Thanks……
hello brother
first of all thank you for this circuit and now i need your help. i am new to this field and i am going to design 50 Hz sine wave inverter and for that i need basic ideas so plz will you upload or send me the complete circuit for squarewave inverter.
The design is simple and reliable ensure that d FET conduct alternately
pls don,t use zener diode in Q1 and Q2 in series just attach 4.7k resistor in Q1 and Q2 in series for protection just add zener diode after 4.7K and ground the zener. in mosfet side @ drain side just add 5watt rectifier diode and ground the diode…. hope you injoy my englesh thx
Thanks for the suggestion. The above design is proven to be problem less, but you can do your project with your theory. If that works perfect I hope you’ll share your project details for others help.
please change the symbol IN4148 IT IS NOT ZENER DIODE IT IS HIGH SPEED SWITCHING DIODE
Actually for a quite long time I considered IN4148 as a zener diode seeing the package. We can consider IN4148 as a zener diode with 75V rating.
Thanks for dropping the comment.
Dear Arup, you have posted hundreds of circuits here and I have been following your site for a long time now. I am highly surprised to know that you decide on a device by looking at it's package! So, if you see a small black package with three legs sticking out, you will call it a transistor?
Secondly, in my opinion, the two diodes in this circuit are not serving any purpose at all. When the Q pins of the IC goes high, the diodes are forward biased and simply conduct the current into the mosfet gates. In fact, the post by warchen is the correct solution, but even he has forgotten to mention the zener diode voltage. The zener diodes simply help in limiting the output voltage of the IC and produce a better and sharper square wave.
And how have you decided that a 1N4148 can be considered as a 75 volt zener diode? If you have any relevant information or literature on this, please let me know. I don't intend to be critical, but would be glad to help you in any way I can. Thanks
1. I haven't reached the 100 mark yet.
2. I don't have any degree in electronics, I learn by 10% reading 40% observing, 40% failing and 10% guessing.
3. Yes, there was a time when I considered all TO-92 devices as transistor until I met the 78L05 regulator.
4. IN4148 has reverse voltage as 75V as per the datasheet and hence a zener breakdown must occur at 75V in reverse bias.
5. Thank you for all of your suggestions back from the FM transmitter article.
6. This article is almost 2years old if you look at the date. I've learned many things in these days. I'd appreciate your suggestions in recent articles.
Hi Arup.
I have really enjoyed your answer!
Your truthful approach to my post is admirable.
1. I am sorry I failed to notice the date of this article, but then I don't see articles based on date. I simply click on an article based on it's topic.
2. The question here is not of the reverse breakdown voltage of 1N4148, the question is what the hell is this diode doing here? Even if we agree that it may act as a zener diode, but how is a 75V zener helping this circuit? The operating voltage around this portion of the circuit is about 12V DC. Moreover, both the diodes are forward biased, so zener action does not arise. I don't want to be too critical again, but let us be more practical and simplify the circuit by removing redundant components. The least you can do is to change the zener diode symbol into a diode symbol at least. The article may be 2 years old, but your latest post was on 13 March, 2012 (about 17 days ago)but unfortunately you have not had the time to change the diode symbol in 2 years.
3. On a lighter note, I have a brotherly suggestion for your second point above....you shall have to increase the 10% reading to at least 60% reading, observing should not be more than be 25%, Guessing can remain at 10% and failing will automatically come down from a drastic 40% to a mere 5%. If you are interested to know why I have reduced observation from 40% to 25%, you may contact me personally, my email address is with you.
Rest assured, I mean good to you and your projects. Thanks for your prompt response.
Hello Mr. Mitra,
Please help me with this circuit? I know it's 7yrs back's post, but can please be so kind to send me this 500watt circuit diagram as per your revision without the redundant parts. I really need it. Thanking you in advance sir. clivaro@gmail.com
Please Post the MOSFET connections and Transformer Image in the circuit diagram.otherwise it is being very difficult to make this circuit.Thanks in advance!
Hi
Take a look at Mujtaba's demo at http://circuitsdiy.com/a-complete-inverter-project
Hi Arup,
It's good that you have updated the circuit diagram. Please check that the original smaller version of the circuit is still the same, only the enlarged circuit schematic is updated. If possible, please correct the glitch. Thanks.
Done. Thumbnail updated too.
hi Chinmoy Mitra. please help me the difference btn sine wave and square wave
hi arup we have no frequency meter, what value or resistor should be replace in potentiometer to fix the frequency to 50 or 60 hrz.thanks
You can use calculated resistor value, but for accuracy in frequency I'd recommend you to use a DIY USB oscilloscope to analyze the waveform.
Which IC can be used an equivalent IC for IC CD4047
No substitute for this, however you may find the same IC with different prefix and suffix characters.
Hi, i am saravanan i have one dovet, which place that the 10k rirestor will place it that
Dear ARUP
How we can add one battery charging circuit and modify this circuit like an emergency light system.
Arup I just discovered this page....... And wow is it very interesting please. Do. You have any more pages on electronics? And do you have any notes on sg3524 oscillator and what determines the. Power of t thanks a. Lot for sharing
i have also use same concept of adding mosfet to the ic ,mosfet get too hot ,it is not working properly