LED drivers adapt the AC mains current to the voltages and currents needed to power the LEDs.

They fall into two main categories:

- constant voltage (12 V 24 V or 48V): for LED strips, where the voltage is fixed and the current depends on the number of connected LEDs. The product of voltage by current determines the maximum power available from the driver.

- constant current: the current is fixed and the voltage depends on the number of connected LEDs. Again, the product of voltage by current (power required by the load) determines the supply power.

Some constant current drivers can be adjusted by means of a 0-10V input signal or by means of a control button, which, when pushed, determines the brightness level of the LEDs.