Switched vertical deflection system

A switched vertical deflection system comprising:

• a first series circuit including first and second switches, first and second sources of horizontal deflection rate voltage and first and second inductors;
• a capacitor;
• a second series circuit including said first switch, said first source of horizontal rate voltage, said first inductor and said capacitor;
• a third series circuit including said second switch, and second source of horizontal rate voltage, said second inductor and said capacitor;
• modulator means responsive to horizontal and vertical deflection rate signals for producing overlapping series of respective increasing and decreasing width horizontal rate pulses during each vertical deflection cycle respectively coupled to said first and second switches for controlling the conduction thereof for charging said capacitor to a first polarity through said second series circuit and to a second polarity through said third series circuit, said first series circuit conducting current of first and second polarities from said second and third series circuits such that only the amplitude difference between said first and second currents charges said capacitor when said pulses overlap;
• and
• a vertical deflection winding coupled to said capacitor for providing a discharge path therefor for producing a substantially linear sawtooth alternating current in said deflection winding during each vertical deflection cycle.

A switched vertical deflection system for producing a sawtooth current in a vertical deflection winding, comprising:

• a first series circuit including a first switch, a first source of horizontal retrace pulses, a first inductor and capacitor, said first source of horizontal retrace pulses being poled to cause current to flow in a direction to charge said capacitor in a first polarity direction, said first inductor and said capacitor being tuned to a frequency lower than the frequency of said horizontal retrace pulses;
• a second series circuit including a second switch, a second source of horizontal retrace pulses, a second inductor and said capacitor, said second source of horizontal retrace pulses being poled to cause current to flow in a direction to charge said capacitor in a second polarity direction, said second inductor and said capacitor being tuned to a frequency lower than the frequency of said horizontal retrace pulses;
• a vertical deflection winding coupled in parallel with said capacitor to form a parallel resonant circuit having a period substantially equal to twice the desired vertical retrace interval;
• a source of signals having a frequency equal to the desired vertical deflection rate;
• a modulator coupled to receive said horizontal retrace pulses and to said source of signals having a frequency equal to said desired vertical deflection rate for producing first and second sets of timing pulses, said first set of timing pulses occurring during the first half of said sawtooth current interval and having leading edges which occur increasingly later than the leading edges of said retrace pulses, said second set of timing pulses occurring during the second half of said sawtooth current interval and having leading edges which occur increasingly closer to the leading edges of said retrace pulses;
• and
• means coupling said first and second sets of timing pulses to said first and second switches, respectively, for initiating conduction of current through said switches at the time of said leading edges of said timing pulses during said sawtooth current interval.