A dimmer switch, comprising: a dimmer circuit configured to output a dimming control signal (450, 950, 1050) to control one or more dimmable light sources (410, 910, 1010) of a lighting fixture; a power metering circuit configured to monitor power consumption of the one or more dimmable light sources (450, 950, 1050); and one or more control devices configured to perform operations, the operations comprising: adjusting the dimming control signal (450, 950, 1010) to sweep a dimming range of the one or more dimmable light sources (410, 910, 1010); and obtaining data (470, 970) associated with power consumption from the power metering circuit while adjusting the dimming control signal (450, 950, 1050), wherein the data (470, 970) is indicative of a power signal (422, 922) associated with powering the one or more dimmable light sources; characterized by: obtaining one or more derivatives of the power signal (422, 922); determining a low-end trim setpoint for the dimming control signal (450, 950, 1050) based, at least in part, on a phase angle of the power signal (422, 922), the data (470, 970) associated with power consumption, and the one or more derivatives of the power signal (422, 922); and adjusting a range of the dimming control signal (450, 950, 1050) based, at least in part, on the low-end trim setpoint. a dimmer circuit configured to output a dimming control signal (450, 950, 1050) to control one or more dimmable light sources (410, 910, 1010) of a lighting fixture; a power metering circuit configured to monitor power consumption of the one or more dimmable light sources (450, 950, 1050); and one or more control devices configured to perform operations, the operations comprising: adjusting the dimming control signal (450, 950, 1010) to sweep a dimming range of the one or more dimmable light sources (410, 910, 1010); and obtaining data (470, 970) associated with power consumption from the power metering circuit while adjusting the dimming control signal (450, 950, 1050), wherein the data (470, 970) is indicative of a power signal (422, 922) associated with powering the one or more dimmable light sources; characterized by: obtaining one or more derivatives of the power signal (422, 922); determining a low-end trim setpoint for the dimming control signal (450, 950, 1050) based, at least in part, on a phase angle of the power signal (422, 922), the data (470, 970) associated with power consumption, and the one or more derivatives of the power signal (422, 922); and adjusting a range of the dimming control signal (450, 950, 1050) based, at least in part, on the low-end trim setpoint. adjusting the dimming control signal (450, 950, 1010) to sweep a dimming range of the one or more dimmable light sources (410, 910, 1010); and obtaining data (470, 970) associated with power consumption from the power metering circuit while adjusting the dimming control signal (450, 950, 1050), wherein the data (470, 970) is indicative of a power signal (422, 922) associated with powering the one or more dimmable light sources; characterized by: obtaining one or more derivatives of the power signal (422, 922); determining a low-end trim setpoint for the dimming control signal (450, 950, 1050) based, at least in part, on a phase angle of the power signal (422, 922), the data (470, 970) associated with power consumption, and the one or more derivatives of the power signal (422, 922); and adjusting a range of the dimming control signal (450, 950, 1050) based, at least in part, on the low-end trim setpoint.