Can the switching power adapter be replaced by a transformer?

Switching power supply sweetening machine can not be directly replaced by transformer, because switching power supply outputs direct current, while transformer can only transform voltage, and the output is still alternating current.

"Direct current" (DC for short), also known as "constant current", is a kind of direct current with constant magnitude and direction. 1747, Franklin put forward the law of conservation of charge according to experiments, and defined the terms of positive charge and negative charge.

Constant current means that the magnitude (voltage level) and direction (positive and negative poles) do not change with time (relative range), such as dry cells. Pulsating DC means that the direction (positive electrode and negative electrode) is constant, but its magnitude changes with time. For example, we get a typical pulsating DC after rectifying 50Hz alternating current by diode and 50Hz pulsating DC by half-wave rectification. If it is full-wave or bridge rectifier, it will get a pulsating DC of 100Hz. Only after filtering (using inductance or capacitance) will they become smooth DC. Of course, there is still a pulsating component (called ripple coefficient).

Alternating current (AC) refers to the current whose magnitude and direction change periodically. Because the average running value of periodic current in a period is zero, it is called alternating current, or AC for short. The English abbreviation is AC. Different direct currents have the same direction. Usually the waveform is sinusoidal. Alternating current can effectively transmit electricity. But there are actually other waveforms, such as triangle wave and square wave. The commercial power used in life is sine wave alternating current.