Patent ID: 7248233

Claim:
A control circuit of a power supply delivering a supply current to an inductor connected in series with a horizontal deflection yoke of a cathode ray tube display for displaying pictures comprised of successive lines, said inductor being the primary coil of a low/high transformer operatively connected for delivering a rectified low-pass filtered biasing voltage to the anode of the display, said low-pass filtering having a first time constant corresponding to the duration of a small number of pictures, said control circuit comprising: feedback means for generating a monitoring voltage substantially proportional to said biasing voltage and for controlling said supply current so as to keep said monitoring voltage equal to a reference voltage; and feedforward means for measuring the cathode current supplied to the cathode of the display and for adding to said monitoring voltage a compensation voltage corresponding to said cathode current, low-pass filtered with a second time constant corresponding to the duration of a small number of lines and high-pass filtered with said first time constant.