collector (slip rings) of an alternating current machine ,ac power: slip rings — continuous rings for alternating flow - 交流電 幅插畫檔、美工圖案、卡通及圖標
first magneto-electric machines, 19 century, wood engravings, published in 1877 - 交流電 幅插畫檔、美工圖案、卡通及圖標
black and white checkerboard pattern with evenly spaced alternating squares across the entire image, creating a high-contrast geometric surface. - 交流電 幅插畫檔、美工圖案、卡通及圖標