Subject: how will you convert a periodic digital signal into an analogue one

given a d.c. voltage source,can you give me circuit by which i can get a sine 
wave
the circuit should be capable of withstanding atleast a 100 amps
all the circuits i have come across use transistors or op.amplifiers.
i was thinking of converting the d.c. voltage into a square wave and then use a 
fourier transform to approximate it into a sign wave
once again the circuit should be capable of withstanding currents greater than 
100 amps
i guess its possible as it occurs in a ups

Re: how will you convert a periodic digital signal into an analogue one