Control circuit for reducing of total harmonic distortion (THD) in the power supply to an electric load

A control circuit for reducing Total Harmonic Distortion (THD) in the power supply to an electric load, comprising:

• a. An input stage for receiving a network voltage and providing a corresponding rectified sinusoidal output supply voltage;
• b. An output stage associated with said input stage for providing power supply to an electric load;
• c. A control module configured to control the power factor and the harmonic distortion (THD) of the energy obtained from said network voltage, by regulating a pulse current that acts upon the power supply absorbed by said output stage;
• d. A regulating module configured for:
• Sensing a main signal representative of said supply voltage;
• Comparing said main signal with a preset reference;
• Generating a regulating signal designed for said control module
• wherein said control module is configured to modify the pulse current according to said regulating signal;
• wherein said control module comprises a processing unit, which is designed to receive an input signal representative of said supply voltage, to receive as an input, through a first reading branch, a current sense signal representative of said pulse current and to control said pulse current according to said input signal and said current sense signal;
• wherein said regulating module is configured to:
• determine whether said main signal is representative of whether said supply voltage is below a given threshold or not;
• if it is not, allow said processing unit to receive said current sense signal through said first reading branch;
• if it is, generate said regulating signal to act upon said first reading branch, such that said processing unit receives, through said first reading branch, a modified current sense signal whose value is smaller than said current sense signal.