求翻译：式中n称为电压比(圈数比).当nN2，U1>U2，该变压器为降压变压器。反之则为升压变压器。是什么意思？

Where n is called the voltage ratio (turns ratio) when n <1, then N1> N2, U1> U2, the transformer step-down transformer. On the contrary, compared with step-up transformer.

Where n is called voltage than (laps). When n < 1 than when U N 1> N 2, 2, 1> U buck transformers for the transformer. Conversely, a booster transformer.

The transformer two group of coil turns respectively are N1 and N2, N1 are primary, N2 is secondary.Adds an alternating voltage in the primary coil, can have the induced electromotive force in the sencondary coil both sides. When N2>N1, its induced electromotive force must the voltage which prima

N called the voltage ratio (than). When n<1 is are N1>N2,U1>U2, the transformers step-down transformer. While as a step-up transformer.

-N is called voltage ratio (number). When you are n<1, N1>N2,U1>U2, the transformer is a step-down transformer. While as a step-up transformer.