In baseball or softball, pitching machines are often used in practice to deliver a pitch to a batter. Similar machines deliver tennis, soccer or volleyballs to a player to aid them in practicing. The ball is usually propelled by one spinning wheel or several wheels combined. Some machines use up to three wheels to deliver different styles of pitches, such as curve balls, sinkers or sliders.
The driving wheels need to be variable speed to deliver high-speed pitches to Major League hitters, or slower speed pitches to Little League hitters or softball players. Although the wheels typically have a high inertia, they need to change speed quickly to minimize the amount of time a hitter has to wait between pitches.
KB's solution was the compact mini-regen drive called the KBMG series of DC Drives. The KBMG can provide variable speed to DC motors up to 2 HP, while being powered from a single-phase 115 VAC line. This allows the machine to be used on a diamond or court where only normal household power is available.
The regenerative feature allows the wheels to change speed quickly in spite of their inertia. The rapid response of the KBMG brings the wheel back to speed quickly after each pitch.
The KBMG series motor drives also have a fast acting current limit circuit to prevent motor overload from the momentary high torque requirement during a pitch.