US Patent No. 10,219,335

FORWARD CONVERTER HAVING A PRIMARY-SIDE CURRENT SENSE CIRCUIT


Patent No. 10,219,335
Issue Date February 26, 2019
Title Forward Converter Having A Primary-side Current Sense Circuit
Inventorship Dragan Veskovic, Allentown, PA (US)
Assignee LUTRON ELECTRONICS CO., INC., Coopersburg, PA (US)

Claim of US Patent No. 10,219,335

1. A load control device for controlling an amount of power delivered to an electrical load, the load control device comprising:first and second semiconductor switches electrically coupled in series and configured to be controlled to generate an inverter voltage at a junction of the first and second semiconductor switches;
a transformer comprising a primary winding electrically coupled between circuit common and the junction of the first and second semiconductor switches, the transformer further comprising a secondary winding adapted to supply current to the electrical load, the transformer configured to transfer power to the secondary winding when either of the first and second semiconductor switches is conductive;
a capacitor electrically coupled between the junction of the first and second semiconductor switches and the primary winding of the transformer to cause a primary voltage across the primary winding to have a positive polarity when the first semiconductor switch is conductive and a negative polarity when the second semiconductor switch is conductive;
a controller configured to control the first semiconductor switch to control a load current conducted through the electrical load; and
a current sense circuit configured to receive a sense voltage representative of a magnitude of a primary current conducted through the primary winding, the current sense circuit comprising an averaging circuit configured to average the sense voltage when the first semiconductor switch is conductive to generate a load current control signal that is representative of a real component of the primary current.