The PCB heated was developed by Josef Prusa. Thus any other new design will always be based on this model. The heated works based on the theory that when an electric current is passed through a conductor, it produces heat that is proportional to the number of amperes flowing through it. Such as, a heated can be set produce as low as 120W of power or 200W depending on the needs at either 12 or 24V. Notice that the resistance of the passionate determines the wattage that will be dissipated.