Power Supply Types

Power supplies typically have two basic design formats, known as linear and switched[-mode]. The linear supply is a relatively simple design that becomes increasingly bulky and heavy for high amperage devices. The switched supply is capable of being much smaller and more efficient but its design is much more complex and sophisticated.

Here we just introduce the switched power supply in our company for you:

Switched mode power supplies have an absolute limit on their minimum amperage output. They are only able to output above a certain wattage and cannot function below that point. In a no-load condition the frequency of the power slicing circuit increases to great speed, causing the isolation transformer to act as a tesla coil, causing damage due to the resulting very high voltage power spikes. Switched-mode supplies with protection circuits may briefly turn on but then shut down when no load has been detected. A very small low-wattage dummy load such as a ceramic power resistor or 10 watt light bulb can be attached to the supply to allow it to run with no primary load attached.

Refer to wikipedia