A load control device (such as, a dimmer switch) for controlling the amount of 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 to the gate of the thyristor, a control circuit, and an RF receiver for receiving an RF signal. The control circuit causes the gate coupling circuit to conduct a gate current to render the thyristor conductive at a firing time during a half cycle of the AC power source, and allows the gate coupling circuit to conduct the gate current at any time from the firing time through approximately the remainder of the half cycle. The thyristor is able to remain conductive independent of the magnitude of a load current conducted through the thyristor and to conduct the load current to and from the electrical load during a single half-cycle.