Forward converter having a primary-side current sense circuit

A load control device for controlling an amount of power delivered to an electrical load, the load control device comprising:

• a transformer comprising a primary winding electrically coupled in series with a first semiconductor switch and a secondary winding adapted to supply current to the electrical load;
• a controller configured to control the first semiconductor switch to control a load current conducted through the electrical load, the controller configured to control the amount of power delivered to the electrical load to a target amount of power;
• 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 configured to average the sense voltage for an on time when the first semiconductor switch is conductive plus an additional amount of time to generate a load current control signal that is representative of a real component of the primary current.

An LED driver for controlling an intensity of an LED light source, the LED driver comprising:

• a transformer comprising a primary winding and a secondary winding adapted to supply current to the LED light source;
• a controller configured to control a load current conducted through the LED light source to control the intensity of the LED light source to a target intensity;
• 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 configured to average the sense voltage when a magnitude of a primary voltage across the primary winding is positive and greater than approximately zero volts to generate a load current control signal that is representative of a real component of the primary current.