An analog signal is composed of four basic components: DC and AC magnitudes, frequency, and phase.
2
德州的西南电力联营(Southwest Power Pool)正在设计一个直流交流综合系统使在西德克萨斯州的1千亿瓦的风力发电产物能传输出去。
The Southwest power Pool of Texas is designing an integrated system of DC and AC transmission to enable development of 10 GW of wind power in western Texas.
3
二极管是将交流电整流成直流电的电子装置。
Diodes are electronic devices which rectify alternating current to direct current.