ac switch

基本解释

It is propitious to develop interfaces for SVC. Switching and controlling performance can be improved by AC switch based IGBT.
基于IGBT的交流开关能够改善投切电容器装置的开关特性和可控性，有利于提高其补偿性能。
Voltage detect of three phase AC, the warning of over-voltage, under-voltage, lost phase and power failure, two-way AC circuits switch full-automatically.
三相交流电压检测，过压、欠压、缺相、停电告警，全自动双路交流前换功能；
shcya.com
The utility model provides an electromagnetic system for low-voltage AC magnetic switch.
一种低压交流磁力开关的电磁系统。
ip.com

Toward the right, you've got the USB type B connector that runs to your laptop, the AC adapter jack, and the master power switch.
ENGADGET: Native Instruments Traktor Kontrol S4 review Alt
Maybe my AC is working too hard and I need to switch if off before an emergency occurs.
FORBES: When the lights went out, my light went on