英语翻译Voltage & Frequency 电压和频率AC mains in Australia is usuall

英语翻译
Voltage & Frequency 电压和频率
AC mains in Australia is usually specified as either 230 or 240V,with a frequency of 50 Hz.(cycles per second).
This specified voltage is what is called an RMS (Root Mean Square) voltage.It's not a constant voltage like DC.Voltage and current are constantly varying around a reference point,following a sinewave pattern.(The waveform on the mains is rarely a pure sinewave.It is often distorted or 'dirty',due in part to some equipment drawing power in spurts rather than at a constant rate).50 cycles of this sinewave are completed every second.The peak-to-peak voltage of this sinewave is the RMS voltage multiplied by 1.414 (the square root of 2).If we assume the RMS voltage to be 240 Volts,the voltage from one peak of the sine wave to the other is 240 * 1.414 or 340 Volts.
This actual RMS voltage from the mains is not usually very steady.It varies with loads on the circuit,location and the time of day.The voltage at my house varies from around 230V to over 250V.
Electric Lights & Frequency
Normal flourescent and incandescent lights turn on and off 100 times per second (twice the frequency),but because of our persistence of vision,they appear to stay on.With electronic controllers used occasionally on normal flourescent lights and usually on one-piece CFL's,extra circuitry is included which converts the 240V AC into DC,then back into AC but at a frequency of around 20 to 30 kHz (20,000 to 30,000 cycles per second),which usually eliminates any perceivable flicker.It also enables the tube to run more efficiently.

电压与工频
在澳大利亚的大多数地区交流电压特定为230V或是240V,工频为50Hz(每秒种周期变化数）.这种特定的电压被叫作RMS（均方根）电压.它不像直流电压那样恒定不变.电压与电流总是随着时间的变化而以正弦波形式变化.（总体上这种波也不是纯粹的正弦波.这是因为一些设备间歇性的启停而非常年运行对其进行干扰.）每秒50个周期的这种正弦波确实每秒都如此.这种正弦电压的峰值电压是RMS电压乘以1.414（2的平方根）.如果我们假定RMS电压为240V,那么它的峰值电压为240*1.414＝340V.
多数情况下,实际的RMS电压不是很稳定.它的稳定性与电路上的负荷,用电距离及时间有关.我家里的电压波动一般为230左右到超过250V.
电灯与工频
普通荧光灯与白炽灯每秒钟会被开关（点亮熄灭）100次（工频的两倍）.但由于我们眼睛的视觉暂留特性,就产生使我们觉得它们好像一直是亮着的认知.在普通荧光灯中安装电子控制器（这种情况很少）,一般情况下通常在单管节能灯中安装这种电子控制器,并设计专门的电路用来将240V交流电转换为直流电,然后再转换成工频大约为20--30kHz（每秒钟20000到30000周期变化）的交流电.通常情况下,这种电灯能消除所有可视见的闪烁.它也同样使的灯管运行更节能.