500W_inveter

[MP1]

I forgot to answer your original question.

You are using the Divider output, which is Pin #1 on the MM5369. It is only used as a 60 hz square wave generator at this point.

MP

 

[ren_ADD]

hi guys,

Thank's a lot!!!

ren.

 

[ren_ADD]

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

Ren

 

[audioguru2]

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.

 

[ren_ADD]

hi audioguru,

it seems that Rhon is not around because i've sent an email to him
two weeks ago but until now he don't have any reply.

Any I want to ask about the 500W inverter. What is a METALIZED FILM CAPACITOR
is it also called the TANTALUM capacitor?

Thank's

Ren

 

[audioguru2]

Hi Ren,
A metallized plastic film capacitor could also be called a mylar capacitor. Over on your side of the pond they are called "green-caps". The 0.1uF/5% capacitor would be marked "104J" if it is a green-cap. I've also seen reddish-brown ones. ;D

 

[ren_ADD]

AHhhh!!! ok now i know. It is only a mylar capacitor not any of the specials.

thank you audioguru!

 

[sureshv]

Hi. I had this unusual problem with the inverter when I connected the batteries. Initially at lower loads (50 watts) it worked fine. But when I started connecting additional loads (100 watts) and batteries in parallel, the inverter would work for 15 seconds and then stop functioning. The emitter resistors would get hot indicating a stuck oscillator. Finally, I managed to blow up the IC probably because of an inrush during one of those off cycles. The power transistors were all safe! In hindsight, I feel, the input voltages to the IC needs to be fed through a resistor of a nominal value say 100 ohms - the circuit consumes just about 10 mA. Secondly, a relay in the circuit that cuts of the low side supply to the square wave generator first followed by a delayed cut off the high side supply will reduce the load on the power line switch/ relay. Any one had similar experience?

 

[audioguru2]

Hi Sure,
Welcome to our forum. ;D
The oscillator in a CD4047 is pretty simple and is guaranteed to work with a supply voltage of 3V to 18V or more (22V for TI). Since yours stopped then later blew-up, I think it was bad from the start.

I agree that adding a 100 ohm resistor to feed its power is a good idea. Adding a 12V zener diode across it would be even better. ;D

 

[sureshv]

My replacement circuit will have a 100 ohms resistor and a 12V zener (500mw). I will report modifications once I finish the project.

 

[kachew]

hi there, i am kachew here....hehe....can i ask  about the sine wave inverter circuit? did anyone try on the circuit post by MP? because i now have similar project on inverter too....my output also need be a sine wave output and surge capability 300W can anyone help me in this project coz after i read all the posts also not really understand and i;m weak in electronics theory...plz help me... :'(
thanks

 

[argeelektronik]

 

[audioguru2]

Hello Aregee,
You didn't say a word about the output stage of a sine-wave inverter you attached that works with PWM to be efficient.
Does it work?
How much power?
Which Mosfets?

 

[argeelektronik]

 

[audioguru2]

It looks like the LM324 makes a 50Hz square-wave. The TL494 just breaks it up into a higher frequency so its average output voltage is half of 220V.
Isn't the transformer made special to pass the high frequency from the TL494?
Why doesn't it make a PWM sine-wave output?