Some switches also contain a rheostat to control the brightness of the instrument panel lights. 一些开关也包含一个可变电阻器，控制仪表板灯的灯光亮度。
The rheostat is operated by rotating the control knob, separating it from the push-pull action of the main lighting switch. 可变电阻器由旋转的控制手柄操纵，与灯光总开关的推一拉的操纵是分开的。
