主しゅ制せい御ぎょ機き構こう

• 制せい御ぎょ装そう置ち

  制御装置 is a broader term for any control device, while 主制御機構 specifically refers to the main or primary control unit in a system.

• 中ちゅう央おう処しょ理り装そう置ち

  中央処理装置 (CPU) is a specific type of main control unit in computers, whereas 主制御機構 can refer to the main controller in various systems, not limited to computing.

Compound of 主 (main) + 制御 (control) + 機構 (mechanism, unit). A straightforward technical term formed from standard Sino-Japanese morphemes.