External power is supplied by connecting to the terminal block located on the hub. For when an external power adapter is required check out the Accessories & Replacement Parts section on this product page. To view all of our hub accessories and power supplies, visit the category here.
To determine the power requirements, the equation to use is P = 5 * I * N, where:
P is the power wattage.
5 is the USB port voltage.
I is the current of the USB port in Amps (USB 2.0 is 0.5A, USB 3.0 is 0.9A.
N is the number of USB ports.
As an example using the equation, a 4 port hub would reflect a minimum wattage of 18 watts.
Knowing the minimum requirement, a proper power adapter can be chosen. In this case the voltage of a power supply should be within 7 to 24 or 7 to 40 Volts DC, depending on the specifications of the USB hub. Also, the power supply must convert AC to DC (no AC output).
Power supplies often come with a voltage (V) rating and an amperage (A) rating. To determine the current in amps, use I = P / V, where the following is true:
I is the current of the power supply.
P is the calculated power of the hub.
V is the chosen voltage of the power supply
Continuing the example, the 4 port hub requires 18 W and the power supply you choose is 12V, the current of the power supply would be I = 18/12, I = 1.5A.
Our full collection of power adapters can be found here.