Patent ID: 8988058
Filing Date: 2015-03-24
Classification: H02M,H05B,Y02B,Y10S

Abstract:
1. A load control device for controlling the amount of power delivered from an AC power source to an electrical load, the load control device comprising: a thyristor adapted to be coupled in series electrical connection between the AC power source and the electrical load for conducting a load current from the AC power source to the electrical load, the thyristor having a gate for conducting a gate current to render the thyristor conductive; a first circuit coupled to the gate of the thyristor for conducting the gate current when the first circuit is conductive; a second circuit coupled to conduct the load current when the thyristor is non-conductive; and a control circuit operatively coupled to the first and second circuits for individually rendering the first and second circuits conductive and non-conductive, the control circuit configured to render the first circuit conductive to conduct the gate current to render the thyristor conductive at a firing time during a half cycle of the AC power source, the control circuit continuing to control the first circuit to be able to conduct the gate current again after the firing time; wherein the control circuit is configured to render the first circuit non-conductive before the end of the half-cycle, such that the first circuit is not able to conduct the gate current through the gate of the thyristor and thereby allowing the thyristor to become non-conductive before the end of the half-cycle, the control circuit configured to control the second circuit to be conductive to conduct the load current after the thyristor becomes non-conductive.