Powering LED Strip with Arduino using Transistor
You need to control the current going through the LED strip. You can control the Vgs of the MOSFET to turn the current on and off. You put the MOSFET on the low side because that way you can use the Arduino's low-voltage output to apply 0V or 3.3V (5V depending on the Arduino) to the gate of the MOSFET. Because the source of the MOSFET is grounded, that controls the MOSFET Vgs (the voltage between gate and source) turning it on and off.







simulate this circuit &ndash; Schematic created using CircuitLab