一台三相变压器原边额定相电压为220V,原副边的匝数为N1=1732,N2=500,副边的额定相电压为________,若副边采用Y接,副边输出的额定线电压为_______。
A campus emergency ______ occur at any time of the day or night, weekend, or holiday, with little or no warning.
免费的网站请分享给朋友吧