Horizontal raster centering circuit for a projection television receiver

A horizontal deflection circuit for driving red, blue and green horizontal deflection coils (LHG, LHB, LHR) of red, blue and green cathode ray tubes, respectively, in a projection television receiver, said horizontal deflection circuit comprising:

• a high voltage (B+) supply;
• a line inductance coil (T1) coupled on one side to receive the high voltage (B+) from the high voltage supply;
• a switch (Q1) for selectively coupling another side of said line inductance coil (T1) to ground;
• a parallel arrangement of a damping diode (D1) and a retrace capacitor (CR) coupled across said switch (Q1);
• said red, green and blue deflection coils (LHG, LHB, LHR) each having a first end coupled to said another side of said line inductance coil (T1) and a second end;
• and
• capacitance means (CS, C1, C2) for coupling said second ends of said red, green and blue deflection coils (LHG, LHB, LHR) to ground,
• wherein said horizontal deflection circuit further comprises a circuit for effecting horizontal centering of display rasters generated by said red, green and blue cathode ray tubes, said horizontal centering circuit comprising:
• an inductance coil (L4) having a first end and a second end;
• means for coupling the first end of said inductance coil to said another side of said line inductance coil (T1);
• a series arrangement of a first and second diode (D4, D5) interconnecting the second ends of said red and blue deflection coil (LHB, LHR), a junction point between said first and second diodes (D4, D5) being connected to the second end of said inductance coil (L4);
• and
• said capacitance means having capacitor means (C1, C2) for coupling the second ends of at least said red and blue deflection coils (LHB, LHR) to a connection node, and S-shaping capacitor means (CS) for coupling said deflection node to ground.