Dc-Ac pure sive inverter design

[soundbag]

Hello out there,

I plan to make the following dc-ac inverter;

1000watts or less,
12vdc car battery will be used;
12dc will be converted to 650vdc peak to peak;
PWM freq. of about 20khz with ferrite or toroid;
650v will be converted to 230vac sq.wave;
sg 3525 will probably be used for pwm;
mofest/ Igbt will be used to convert back to sive wave;
Low pass L-C filter will be used to filter out the harmonics;
Of course there will be a charger for the battery.

I hope to hear from people with more experience on this
design.



SOUNDBAG.

[DigitalJunkie]

Just thought I'd throw this link out there for ya..
http://www.technology.niagarac.on.ca...mcsele/i2k.htm

Good luck!

After looking at that site again,I realised it wasn't a SMPS/PWM type inverter,but it still might be useful?

[cunningham]

You should use an E-core type transformer instead of a toroid.

[soundbag]

Thank you,

May I add here now that,
I dont want to use pic microcontroller thing.
I want something simple other people can build.
I want a schematics of less than 1000watts.
I want a circuits that uses mosgate drivers.

What ever happens to the smps gurus?

PLEASE, THE MODERATOR SHOULD CHANGE THE WORD -

"Pure sive inverter" to "PURE SINE WAVE INVERTERS"

of course, this is due to typo-errror.

I heard that some people are using class- d amp topologies to make a dc-ac inverter now, is it true?

soundbag

[Holger Barske]

Originally posted by soundbag
I heard that some people are using class- d amp topologies to make a dc-ac inverter now, is it true?

Yes, it is. Basically, you could use any Class-D-amplifier, drive it with a sine wave of the desired frequency, provide some amplitude control, and you'll be fine.
Nevertheless you need a DC power supply with some more volts then the desired coverter output voltage.

[soundbag]

Thank you,

I need a schematics of this if you have one or direct me to a site with the information.

Please do you know of a forum where inverters a well discussed?

soundbag

[johnnyx]

I bought a 600W inverter for £30.00 from Maplin in the UK. It is for a boat; 12v dc in, and 240v ac out. It is unlikely to be a pure sine wave, I haven't 'scoped it so I don't know what the waveform looks like, but this sort of thing is now cheaper to buy than build, like many things nowadays.

It depends on your application how important "pure" is.

Even so, you have 90% of the parts you need for only £30. This could supply the high voltage dc for the sine chopper circuit, with perhaps a little modification; why 650v?

I suggest buying one of these, (Chinese made of course), drawing out its circuit, and seeing how it could be modified to suit your purpose. It would be a lot easier than designing from scratch. SMPS are not easy to design.

edit: The schematic is only part of the design

An interesting thread was started a few days ago about re- engineering stuff for purposes not envisaged by the manufacturer, and this could be one of those projects.



Hope you find this helpful.

[soundbag]

650v is the peak to peak for 230vrms when view on a scope, when you switch the power.

The reason for "do it yourself" would have been removed if I have to buy ready made products.

Lets look at it this way;
I wanted to "switched" from my " linear attitude " to making my power with smps, then along the way, class d thing came up, and as I progress the issue of dc-ac inverters/ups came up. The best thing I can do is to follow the thread.

I have not been able to locate the new thread you mention.

Thanks.

___________________________

"measure everything,
dont trust anyman"

[johnnyx]

It was this thread

650v is the d.c. link voltage for 3phase 415v power inverters, I thought maybe the requirement could be reduced for 230v output.

I've built low power smps, which work well, but I find high power stuff a bit too scary. I have modified one to give different output voltages, and this works very well.

I see many high power types at work, and if something's wrong, they go bang. They are very complex beasts, not something to take on lightly.

Good luck in your quest.

[soundbag]

Hi there,

I am still on my project and its getting interesting by the day.

Pls. check www.energychallenge.org for 200l inverter reports.

also look for www.uqm.com 20kw inverters pdf.

I will be back soon.

soundbag