A method of controlling a power supply electrically coupled to a dimmer includes receiving a current pulse-width-modulated (PWM) pulse of a plurality of PWM pulses corresponding to a dimmer level, calculating a current duty cycle of the current PWM pulse, comparing the current duty cycle with a window of validity to determine whether the current duty cycle is within the window of validity, and in response to determining that the current duty cycle is not within the window of validity, determining whether a count of out-of-range PWM pulses having duty cycles not within the window of validity is greater than a threshold, and in response to determining that the count of out-of-range PWM pulses is greater than the threshold generating a sample value corresponding to the current duty cycle for transmission to the power supply.