A cascade MosFet circuit design for variable gear switching using pulse width modulation (PWM) between electronic gears to achieve a smooth transition is disclosed. In an embodiment, in the system, there can be three separate stages of two or more switches from very low amperage to hundreds of amps that can be automatically selected within a chosen stage. The automatic switching can be programmed to be power (e.g., current) sensitive or can be both power and electronic gear sensitive as to cascade into the right MosFet combination for different gear settings and still select greater values for varying power levels. Such a smooth transition can allow the generator or motor using such cascade MosFet circuit design to operate more efficiently and/or more quietly.