Patent attributes
A control circuit for use in a ballast configured for powering a first lamp set and a second lamp set. The second lamp set is operated via a controller and a second lamp driver circuit. The controller enables the second lamp driver circuit as a function of a monitored value corresponding to a current through a lamp of the second lamp set. The control circuit includes first and second input terminals for selectively connecting to the power supply. The control circuit reduces the monitored value as a function of a connection state of the first and second input terminals of the control circuit to the power supply. Thus, the control circuit causes the controller to selectively operate the second lamp driver circuit in order to energize the second lamp set in combination with the first lamp set.
