When it comes to LEDs, LED Strips or LED modules it is a good idea to use a LED Driver to keep the brightness the same.
There are two types of drivers.
Constant Voltage - This type of driver will have a Fixed Voltage Output. This will depend on the LED voltage rating. It will be a fixed output. The current output for the driver will have a max rating. If the circuit does not draw more that what is required it will work.
Constant Current - This type of Driver will have a Fixed Current Output. This is determined by the current for the LEDs. The Voltage output will be variable. The Voltage can change due to the number of LEDs that are used. Make sure the voltage range will be for the voltage that is required.
The LED Drivers can be either a Board Mount style or External/Internal - Off Board style.
In some cases, depending on the LEDs being used, a AC/DC power supply can also work.
Just check on the Data sheet for the LEDs to see the Voltage needed as well as how much current is needed.