Power supplies

Power supplies are used to convert and deliver electrical energy in a form suitable for the connected equipment. They can convert alternating current to direct current (AC/DC), alternating current to alternating current (AC/AC), direct current to direct current (DC/DC), or direct current to alternating current (DC/AC). The choice of power supply depends on the type of input voltage available and the output voltage required by the connected equipment.

CV (Constant Voltage)
The most common type of power supply delivers a constant output voltage (CV). The current varies depending on how much current the connected load draws.

CC (Constant Current)
Power supplies with current limiting (CC) maintain a constant current (Ampere). If the load attempts to draw more current than the set limit, the power supply automatically reduces the output voltage to limit the current. This is commonly used for battery charging and LED driving.

Power
The power of a power supply is calculated by multiplying the output voltage by the maximum output current the power supply can deliver. Example: A power supply with a 12 V output voltage and a 2 A maximum current, can deliver a maximum power of 24 W (12 Volts × 2 Amperes = 24 Watts). The power rating of the power supply should always be equal to or greater than the total power required by the connected load.

Current
My device requires 5 V 1.25 A. Can I connect it to a power supply rated at 5 V 3 A?
Yes, absolutely. The power supply can supply up to 3 A, so the device will only draw the 1.25 A it requires.