Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.
In that inverter circuit, why they have converted the battery DC Voltage to AC and again rectifyng making to High Voltage DC?? Why cant they make the battery DC voltage directly to required AC output through that transformer?? Why they need that many conversion??? Kindly suggest me on this.
It is an SMPS design. It is a 2-stage converter. Instead of standard bulky iron core transformers, ferrite core transformers are used, that work at high frequencies. They are much smaller than the regular bulky iron core transformers. Since they only work at high frequencies, the high frequency AC is converted to DC and a bridge converter is used to convert that DC to 50Hz (or 60Hz) for AC output.
This type of inverter can greatly reduce cost and size compared to bulky iron core transformer based inverters.
You can do that, but not with a ferrite core. The ferrite core can only be used at high frequencies like 50kHz or higher. So, if you pulsate it, at the output you can have 220VAC but at 50kHz (kiloHertz). This can not be used to drive most loads. So, it must be converted to 50Hz and hence the 2nd stage.
If you use an iron core transformer (the bulky ones), you can do it in one step where the transformer can be used at 50Hz.
These can be used for 2-stage conversion inverters and can take quite a lot of load for the size (just look at the size compared to the battery):