No, there are two kinds of switching power supplies, one is constant current, the current is constant, and the voltage changes according to the change of load, and the other is constant voltage, but most power supplies can be fine-tuned. In electromagnetism, the amount of electricity passing through any section of a conductor per unit time is called current intensity, which is called current for short. The symbol of current is I, and the unit is ampere (A), which is called "An" for short (André-Marie Ampère, 1775~ 1836, a French physicist and chemist, has made outstanding achievements in the research of electromagnetic action, and made contributions to both mathematics and physics.