An LED lamp is provided in which the output light intensity of the LEDs in the LED lamp is adjusted based on the input voltage to the LED lamp. A dimmer control unit detects a type of dimmer switch during a configuration process. Using the detected dimmer type, the dimmer control unit generates control signals appropriate for the detected dimmer type to provide regulated current to the LEDs and to achieve the desired dimming effect. The LED lamp can be a direct replacement of conventional incandescent lamps in typical wiring configurations found in residential and commercial building lighting applications that use conventional dimmer switches.