I want to build own circuit using operational amplifier and resistors. I have 12V power source (car accumulator) and 6V input voltage (Vin). I want to get 12V Vout and 25W at the output. So that is about 2A current(25/12=2). I heart that operational amplifiers (OA) work only in low currents. Therefore I am not sure that it is appropriate to use OA to implement my aim. My aim is to get 12V voltage and 25W power at the ouput from input voltage Vin=6V and 12V power source(car accumulator) using following circuit. So is this appropriate circuit? If, no can someone provide alternative curuits? Thanks!