Patent ID: 8941316
Filing Date: 2015-01-27
Classification: G01R,H05B,Y02B

Abstract:
1. A method of determining a dimming control value of a thyristor-switched dimmer, the method comprising: predicting zero-crossings of a voltage of an AC power source that supplies power to the thyristor-switched dimmer; probing the output of the thyristor-switched dimmer by periodically or intermittently applying a minimum conductance across the output of the thyristor-switched dimmer from a turn-on time of the thyristor-switched dimmer circuit at least until the predicting has gathered sufficient information to predict the next zero-cross time of the voltage of the AC power source; detecting a leading edge of a waveform of an output voltage of the thyristor-switched dimmer circuit subsequent to the next zero-cross time; and determining the dimming control value of the thyristor-switched dimmer from a time interval extending from the next zero-cross time of the voltage of the AC power source to the detected leading edge.