It is difficult to produce a very high voltage directly, by a combination of transformer and rectifier.

用变压器和整流器相配合直接得到很高的电压是困难的。

youdao

It is difficult to produce a very high voltage directly, by a combination of transformer and rectifier.

用变压器和整流器相配合直接得到很高的电压是困难的。

youdao