help on a converter and inverter design using SMPS idea

[gchibyk]

hello every one. i love the help u share here.
i am working on a converter of 24vdc in and 170vac out to be used on a 1kw inverter.
plz i want to know, can irf3205 work well as the switcher transistor? or is their any better alternative? and how many pieces can i use.

thanks. am waiting for reply.

 

[kabiru]

Yes,you can use 3205 for your boost coverter and IRF740 for output swiching.

 

[gchibyk]

Thanks so much kabiru..... I tried it and it worked.


Please i will still like to know if snuber circuit will be necessary at that high switching frequency--about 30khz..

Thanks

 

[kabiru]

well using snuber in your boost converter is not necessary because your boost converter has feed back loop for voltage stability.

 

[mtwieg]

I think he means a snubber for high voltage transients or high di/dt.

What do you want to snub? There are different circuits for reducing voltage overshoot and switching speeds.

 

[gchibyk]

THANK YOU SO MUCH ALL FOR YOUR HELP SO FAR...

WELL I AM THINKING OF ADDING A SNUBBER CIRCUIT TO HELP ME TO SUPPRESS THE HIGH di/dv THAT MAY EXIST DUE TO THE PRESENCE OF THE HIGH FREQUENCY FERRITE CORE TRANSFORMER IN THE COVERTER.

PLEASE I WILL LIKE TO KNOW IF THIS IDEA IS RIGHT AND NECESSARY....

ALSO I WILL LIKE YOU GUYS TO HELP ME ON ANY INFORMATION THAT I MAY NEED TO COMPLETE MY PURE SINE WAVE POWER INVERTER THAT USES ANALOG TECHNIQUES...
THANKS SO MUCH.

 

[gchibyk]

Still on the inverter design....
Please i will like someone to explain to me what is a dc blocking capacitor in the primary side of the transformer in a half bridge or full bridge converter and the need for it.
.......thanks so much.

 

[kabiru]

It's posible to achived pure sine wave using analog technics but their will be instability due to complexity of the circute,may be i will get time and start desingning the circute using some digital ic's, i one try to build pure sine inverter using two oscilator's 1st oscilator 10kHz and 2nd oscilator 50Hz i modulate it with and gate 4081 and filter the output with my normal AC capacitor, a pure sine wave output is achived but the problem is the output voltage drop with about 40per cent even if you control the feed back loop to control the carrier freq pulse.

 

[gchibyk]

Thanks so much Kabiru!...Well am yet to develope skills in digital circuit design.
But I still want the circuit that i have been working on for a long time now to work well for me. I still will appreciate any help you will give me to build a very good and efficient sine wave inverter....That is my current project for now...Thanks