to review one's lesson―con one's lesson―con over one's lesson
学課を浚う - 斎藤和英大辞典
A control device CON opens and closes a switch SW in accordance with the size of the load current of an inverter, the resistant value of the gate resistor of IGBT is changed over, and a degree of one hand of the suppressions of the surge voltage of an element and the switching loss is enhanced by the changeover. 制御装置CONは、インバータの負荷電流の大小に応じてスイッチSWを開閉し、IGBTのゲート抵抗の抵抗値を切り替え、この切り替えで素子のサージ電圧の抑制とスイッチング損失の抑制の一方の度合いを高める。 - 特許庁