An AC powered source usually has a significant level (often several volts) of line frequency common mode voltage.

交流供电的源通常具有很高电平的电源频率共模电压(常常有几伏)。

youdao

Because of the stability of LED current, these designs provide an expanded input-ac-voltage range, which may be useful for a multistandard ac-powered gadget;

由于LED电流的稳定性，这些设计使输入交流电压的范围扩大，其有利于多标准交流供电设计；

youdao

It combines a 2-liter DOHC 16V Duratec (Atkinson cycle) engine and CVT with an AC synchronous motor powered by a 7.6kWh Lithium Ion battery.

ENGADGET

In addition to 300 hours of entertainment, ports for USBs MP3s, camcorders and cameras (and AC outlets to keep them all powered), Virgin Atlantic will also trial phone conversations on personal mobile phones later this year.

FORBES: Ready for On-Board Cell Phones?

Since 2005, the company has stood out in the fast-moving LED industry with an innovation that allows LEDs to be powered by alternating current, or AC, rather than requiring a transformer that turns AC into direct current.

WSJ: Seoul Semiconductor's LED-Lighted Path