Power conversion

I need a circuit to help me supply 115V, 28V and 26V 400Hz from 220V 50Hz. Its for school project.

Simplest way is to use a rectifier ...
and convert 220 V 50Hz to DC (about 300 V) then use a dc/ac inverter and make a 400Hz ...
But i don't think that You will get a ready to make schematic ....

You have to see how is made a PC AT or ATX computer power supply...
Then modify it ... but there You will have trouble with frequency ... standard supply work at 30 - 70 kHz (it depends)...

But still i think it will be simplest way ....

But You have to give us more details ...
How much Current You need
if this must be a sinus

?

B regards
Mark

what is the power requirement?

Right how much power? I would use an audio power amplifier and a sine wave generator then use an output transformer to step up the voltage to what you need then run the sine wave frequency to get what you need - just make sure the transformer can deal with 400 hz.

Kevin

Kevin is right , practically I have done it when I have to troubleshoot a
115 V/400 HZ generator governor control unit. I made it using the components
available in my lab. I have used normal 220 V to 30V 50 HZ step down transformer and connect it other way round. Required output voltage can be adjusted by varying input amplitude of Audio amplifier. You may try other transformers and measure it for the required output. Please see the attached block diagram

Thanks a lot for your reply sir. But i have not seen the circuit you said was attached. If i can get a circuit it will help me a lot.

I would want to power a load of say twenty five amps. The idea is. I just want to do something new. We do dont do design and construction in my school. I am doing this to learn and probably start up something in the school.

Thanks a lot. I want to supply a load of say 25amps

Attached herewith is the block diagram to give an idea to built without circuit designing/fabrication because designing and fabrication requires some expereince and equipment.

selection of power amplifier & transformer depends upon your power requirement.
In your case for example 25A at 28 Volts = 700 Watts. approx., so you need a power amplifier
and transformer of about 850 Watts considering the losses.

Thanks a lot sir. There seems to be a great head way. I never thought of the use of power amp but now my eyes are getting opened. The biggest challenge i have is getting stepping up the frequency from My 50Hz supply to 400Hz?
Another thing is the issue of supplying different voltages using the same supply. How will the block diagram look like. For instance 115/28/26Volts from this same project? I really appreciate your assistance sir.

please let me know the exact current requirement for each output voltages
ie 115,28,26 volts. May be I can give some idea for one power supply for all.

Sorry I could not get the exact specification today. I have some exams to write so i will go to the school lab tomorrow by God's grace then get consumption rate of some specific instruments i would want to drive then get back to you. Thanks a lot for your willingness to assist. God bless you.