The illuminance degree in the illuminant circuit is not raised when the voltage is higher than the limited voltage of fluorescent lamp, which leads to the ineffective power of the extra voltage.

• 结果表明，在以日光灯为负载的照明电路中，当电网电压超过日光灯额定电压时，只会造成超额电压部分的无效功耗，并不增加照度；