Patent ID: 8536799

Claim:
A method comprising: receiving an input signal representing a supply voltage signal; detecting a dimmer affecting the supply voltage signal; generating a dimmer detection signal representing detection of the dimmer; determining a type of the dimmer affecting the supply voltage; and generating a dimmer type detection signal; wherein determining a type of the dimmer affecting the supply voltage comprises at least one of (A) and (B): (A) comparing the input signal with a first threshold value; comparing the input signal with a second threshold value; determining a time between when the input signal reaches the first threshold value and the input signal reaches the second threshold value; comparing the determined time with a time threshold value; and indicating that the dimmer is a first type of dimmer if the determined time is above the time threshold value and indicating the dimmer is a second type of dimmer if the determined time is below the time threshold value; (B) determining a voltage difference in the input signal that occurs during a fixed amount of time; comparing the voltage difference in the input signal to a voltage difference threshold value; and indicating that the dimmer is a first type of dimmer if the voltage difference is greater than the voltage difference threshold value and indicating the dimmer is a second type of dimmer if the voltage difference is greater than the voltage difference threshold value.