i can give you some tips in designing inverter, inverter means DC to AC convertion, to convert constant DC magnitude to variable AC magnitude, to change magnitude we have to generate one positive square half cycle and one negetive sqare half cycle later we have to amplify two half cycles and in next step fed to transformer(stepup). at transformer output terminals we can get AC signal. this is basic knowledge to design inverter.
1. to generate two half cycles select Astable multivibrator.
2. to change polarity of half cycle and to amplify use two FET's . (Note: you have to select these based on requirements (output wattage), ans you should use sufficient heatsinks.)
3. slect transformer, a.) should step up transformer b.) number of turns of secondary coil c.) current rating.
try to design by selecting every section with perfect calculations theoritically, and later impliment practically.