A power tool includes a mode switching device that includes a mode switching member turned by manual operation, a linearly moving driven-side member and a mode switching mechanism actuated by linear motion of the driven-side member. The fuzzy logic based adaptive YC separation system includes an adaptive YC separator to use fuzzy logic to separate chrominance data in a video signal, and a panel to display the chrominance data. A first flow passage and a second flow passage are alternately formed in multiple layers between the flat plates.