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I'm a newbie.

I'm having doubts about using square wave output for anything other than a resistive load (e.g. an electric bulb or an electric stove). 

Using it on a flourescent lamp is ok though, 'cause they come cheap.  But for tv and anything else I think there should be some sort of wave- shaping circuit to come up with an output similar to a sine wave.  Perhaps someone could give us a schematic for this purpose.

The circuit is designed for 50 Hz. From the diagram, it seems C1 and R2 controls the clock.  What values are needed to change it to 60Hz?

Finally, if I want a to double the power, can I simply put a larger transformer and double the number of transistors? 

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hi to all,

thanks to audioguru for all the answers.  They're all enlightening.

I'm not much into electronics, but I'm collecting topics on alternative energy sources - wind, solar, etc.

Part of my collection are plans for 5,000W inverter which I downloaded from the internet.  Sorry I can't share it here because it's not my property, but I'll send them to Ronnie.  (Also, they're not purely electronics devices)

I haven't tried building any of them yet.  Perhaps Ronnie could go over the plans, do some modifications and publish them.

Thanks a lot to all you great guys !

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May i suggest about the 500W inverter!

Since the IC CD4047 used to generate an oscillation of squarewave.
can we use the function generator IC, the 8081 IC discuss in the book of Boylestad
and Nashesky. The book is entitled "Electronic Devices and Circuit Thoery"

It's output has  has three different wave. one of those is a sine wave.

Can we use the sine wave output of the IC?

How's that does it make sense?  ;)


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Hi Ren,
The pre-driver, driver and output transistors in the 500W inverter project are designed to switch fully-on then fully off so they don't get too hot.

If you make a 500W sine-wave inverter with any kind of sine-wave oscillator feeding a 500W audio power amplifier that drives a big step-up transformer, then the amplifier will heat with about 400W of heat. The heatsinks would be enormous since a 500W audio amplifier is hardly ever operated at max power continuously.

That's why we are talking about using a high-frequency switching amplifier like a class-D one that modulates its carrier with pulse-width-modulation, but they are complicated and expensive. ;D

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hi Mp, I know that the inverter has an output of a Square - Wave that's why
I'm asking if it is applicable to TV's.
Thanks for the reply ;)

Although others on the group have made positive comments regarding the use of square wave inverters with TV, I would never run a Television from a square wave inverter. At the very least, I would use a modified sine wave inverter and preferably, a sine wave inverter.
Most alternate energy site will warn you that computers, televisions, induction motors, and transformer loads are not recommended to run on square wave because it has a high harmonic content. It is not appropriate for operating sound equipment such as stereos, televisions, nor can it efficiently run capacitor start motors, induction motors and transformer loads

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Hi Mp,

Thank for the circuit.

I just want to ask. How much power can the sine_wave_inverter-1
could it give?

Another thing, could you give me the complete part list of this inverter
because I had problem reading on the schematic some are difficult for me to read.

Thank's a lot.
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Hi Guys,

I am sorry but that’s it, I don’t have any further data on this one. I posted it as a display of this type of inverter in principal not as a complete project. Maybe someone else can come up with more info on this circuit.
Have a Great New Year Guys!

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Hi Mp and Ante,

Ok thanks anyway.

I have another qeustion.

Have you build this iverter?
What are the troubles did you encounter?

From the circuit, what is the pin number of the IC MM5369 fed to IC 4030?

That's all thanks!!!

I hope you don't get anoyed from all of my query... ;) ;)

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Partminer has 1274 in stock. There are also others, but I use partminer because they save me a lot of search time.
There is also a drop in replacement. You can e-mail this guy: [email protected]
to find out what it is since he has already gone through this search process, or you can look for 1998 or 1999 issues of "Electronics Now" Magazine. They had an article of a direct replacement chip.

Also, a replacement for this chip has been discussed here on the forum more than a year ago. The link is here:

I have also attached the datasheet to this message.
If none of this helps, keep in mind that there are many replacement chips that can be used to give you 50 or 60 hz timebase.



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Hi Mp,

From the sine-wave schematic, I just want to ask what is the
Value of the TWO MOSFET? I thuoght that I have read it correctly
but when I print and review it the printout is difficult to read.

Can you also give a circuit or an IC that would replace
the MM5369?

Thank's :) :)

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Hi Ren,
The Mosfets operate linearly in that sine-wave inverter. Therefore they get hot. Really hot.
The inverter's efficiency isn't good. 200W in for 100W out.

It doesn't need the frequency accuracy from an old MM5369 to make a crystal oscillator, any square-wave 50Hz or 60Hz oscillator will clock the function generator IC. The function generator IC can even use its own built-in oscillator.

I wonder where you could find its old obsolete function generator IC. I had one about 30 years ago. The new MAX038 will work.

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