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US 4,028,586 AGranted
Parabolic current generator
AssigneeRCA Corporation
InventorLewis Irwin Mengle
Life of this patent
Estimating the term…
Abstract
A bridge circuit has its input terminals coupled in parallel with an impedance network through which a sawtooth current is passed, the bridge operating to provide an approximate parabolic current through a load coupled to its output terminals. The impedance network includes at least a first impedance coupled in parallel with a series coupled variable second impedance and a third impedance for improving the stability of the parabolic load current.
Claims4
An improved parabolic current generator for providing a convergence correction current in a deflection system utilized in a display system, comprising:
- a deflection generator coupled to a deflection winding for providing an alternating current sawtooth scanning waveform therein;
- said parabolic current generator including a bridge circuit having its input terminals coupled in series with said deflection winding and its output terminals coupled to a convergence correction winding for providing said parabolic correction current therethrough;
- said generator further including first and second impedance networks coupled in series with each other and the two of them coupled in parallel with said input terminals of said bridge, said networks each including a first fixed resistance coupled in parallel with a series coupled potentiometer and a second resistance, the junction of said networks being coupled to one of said output terminals of said bridge for allowing separate adjustment of said correction current during each polarity of said alternating current scanning waveforms and for limiting the amount of correction current flowing through said potentiometer.
Dependencies are inferred from the claim text.