Need international power converter/adapter/voltage transformer

Hello,

My items just arrived from the U.S. and I have some kitchen appliance, like a food processor and juicer, that will not operate with the international power converters that I brought here from the U.S. The appliances require too many watts (750 watts). I have searched in Madina, Palace store on Spintex, and Game at Accra Mall, but no one sells these power converters. Can anyone tell me where I may find these voltage transfomers in Ghana?

Thx!