Patent ID: 8350678
Filing Date: 2013-01-08
Classification: H05B

Abstract:
1. A method of controlling a ballast dimming level for an electronic ballast, comprising: (a) transmitting an AC power signal to the electronic ballast; (b) generating notches on the AC power signal utilizing a power line controller by opening a switch on an AC power line transmitting the AC power signal; (c) varying a time duration of the notches in accordance with a desired ballast dimming level by (d) receiving a notch duration signal associated with the AC power signal; (e) producing a reference signal having an adjustable signal level; (f) associating the time duration of the notches with an amount of time that the signal level of the notch duration signal has a predetermined relationship with the signal level of the reference signal and generating a switch control signal having a first state for opening the switch and having a second state for closing the switch, wherein the switch control signal is in the first state only during one of either the positive or negative half-cycle of the AC power signal; and (g) adjusting the signal level of the reference signal to vary the time duration of the notches so that the ballast dimming level of the electronic ballast is adjusted to the desired ballast dimming level.