A small current flowing from the () to the emitter can control a much larger current between the collector and emitter terminals.
A. base
B. gate
C. P type semiconductor
D. N type semiconductor
查看答案
When reverse-biased, an ideal () would block all current. A real one lets perhaps 10 microamperes through–not a lot, but still not perfect.
A. forward
B. switch
C. resistor
D. diode
电梯的有齿曳引机通过与蜗杆相连,涡轮与曳引轮同装在同一根轴上,曳引绳挂在曳引轮上。
A. 联轴器
B. 花键
C. 轴
D. 离合器
电梯的电磁制动器安装在高速轴靠近的一侧,与曳引电动机之间有连轴器相隔。
A. 蜗杆
B. 涡轮
C. 曳引轮
D. 导向轮
曳引机的电动机不用而直接传到曳引轮上的曳引机称为无齿轮曳引机,一般用于速度≥2.5m/s的电梯上。
A. 制动机构
B. 减速机构
C. 编码器
D. 涡轮蜗杆