Has the device automatic identification of polarity?
设备是否具有极性自动识别功能？
2
The device is equipped with a new type of output current polarity detector, the method is simple and reliable.
装置采用了一种新的输出电流极性检测器，方法简便可靠。
3
In addition, the current controlling device is used to control the amount and the direction of the current, and thus control the strength of the electromagnetic force and the polarity.