The circuit looks good.
You forgot to show transistor numbers, the power rating of the transformer, the current rating of the 12V supply and how the 4047 is wired.
Or forget about using a centre-tapped transformer and use one that isn't (if you have a centre-tapped one then never mind).
with yr 12V have your DC-link capacitance in the form of two seriesed up with the mid-point the virtual-earth the the transformer primary winding goes between the phase output of the power-leg and the virtual-earth
PWM the top-switch with a duty to synth a sine-wave positive cycle and PWM the bottom switch to synth a sine-wave negative cycle.
With control loop closed around a re-scaled version of the outputted 220V (50Hz?)
You made the 500W inverter project from another site. I fixed it, because its oscillator had the wrong value resistor and capacitor.
I also fixed its transistors circuit.
Your transformer is good for 500W output but you forgot to show which transistors you used. Your transistors will limit the output power to about 100W or less.
Your power transistors do not have a resistor from base to emitter to turn them off.
Just going into more detail about what Styx is saying.
I would use a ferrite core transformer connected to a full h-bridge connected to a PWM working at about 40kHz and put a low pass filter on the output to only allow the 50Hz or 60Hz signal to pass.
A pure sinewave inverter isn't that complected, all it is is a class-D amplifier working at an extremely low frequency; it's a lot easier to build than a class-D audio amplifier.
Also not only will it give a good sinewave, it'll be more efficient and more compact than a modified sinewave inverter.
Google for class amplifier if you want more information.
I had red in a book name(modern inverter and converter circuits) that the transformer used in 12v inverter should be 20v center taped.
I dont know that why it should not 24v center taped.
OK thats right but i onley want to know that why some companies which i had absorved that they use 20v (center taped) to 220v transformer. Is it Right?
Hi Gary,
That "5000W" inverter came from this Japanese guy: https://hobby_elec.piclist.com/e_ckt8.htm
It has a whopping 3A from the 12V battery so its output is only 36W.
I think it is capable of producing an output of 50W. Then use 100 of them
Hi Dimper,
The transistors in an inverter have a voltage loss of about 1.5V. But a "12V" car battery is 13.8V or 14.4V when fully charged. So the extra increase in output voltage when a 10V transformer is used is not necessary.
Hello all,
My requirement is quite different. I intend to build a 1.5kVA inverter that will draw less current from the battery when few loads are connected (i.e trying to avoid running down the battery when just a 40W bulb is connected) and progressively draw more current from the batter as the load increases.
This in my view will make the inverter more efficient. Any ideas pls