Patent attributes
A two-wire load control device (such as, a dimmer switch) for controlling power delivered from an AC power source to an electrical load (such as, a high-efficiency lighting load) includes a thyristor coupled between the source and the load, a gate coupling circuit coupled between a first main terminal and a gate terminal of the thyristor, and a control circuit. The control circuit is configured to control the gate coupling circuit to conduct a pulse of current through the gate terminal to render the thyristor conductive at a firing time during a half cycle of the AC power source, and to allow the gate coupling circuit to conduct at least one other pulse of current after the firing time during the half cycle. The load control device is further arranged to conduct current through the electrical load if the thyristor becomes non-conductive and remains non-conductive during the half-cycle.
