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.
基於IGBT的交流開關能夠改善投切電容器裝置的開關特性和可控性，有利於提高其補償性能。
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.
三相交流電壓檢測，過壓、欠壓、缺相、停電告警，全自動雙路交流前換功能；
shcya.com
The utility model provides an electromagnetic system for low-voltage AC magnetic switch.
一種低壓交流磁力開關的電磁系統。
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.
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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