DIS has its own drawbacks by having half of the plugs firing with an acceptable negative voltage, while the other half is fired by the less acceptable positive polarity.
DIS有自身的缺点，由于有一半的插头接通一个可接受的负电压，而另一半接通不太能接受的正极。
2
Together these four sectors accounted for more than half of all medium voltage drive revenues in 2008.
这四个行业在2008年合共占了中压电机全部销售额的一半多。
3
The voltage stress of each main switch is only half of the input voltage.