US Patent No. 10,716,185

LOAD CONTROL DEVICE HAVING A CONTROLLABLE FILTER CIRCUIT


Patent No. 10,716,185
Issue Date July 14, 2020
Title Load Control Device Having A Controllable Filter Circuit
Inventorship Robert C. Newman, Jr., Emmaus, PA (US)
Assignee Lutron Technology Company LLC, Coopersburg, PA (US)

Claim of US Patent No. 10,716,185

1. A load control device for controlling an amount of power delivered from an alternating-current (AC) power source to an electrical load, the load control device comprising:a first terminal adapted to be coupled to the AC power source;
a second terminal adapted to be coupled to the electrical load;
a bidirectional semiconductor switch coupled in series between the first terminal and the second terminal, the bidirectional semiconductor switch configured to be controlled to a conductive state and a non-conductive state;
a filter circuit coupled between the first terminal and the second terminal, the filter circuit comprising a first capacitor and an inductor coupled in series between the bidirectional semiconductor switch and the second terminal, the filter circuit further comprising a controllable switch; and
a control circuit configured to render the bidirectional semiconductor switch conductive and non-conductive to control the amount of power delivered to the electrical load, the control circuit further configured to adjust an impedance of the filter circuit;
wherein the control circuit is configured to render the controllable switch conductive and non-conductive to respectively connect and disconnect the first capacitor from series connection between the first terminal and the second terminal to adjust the impedance of the filter circuit.