Circuit for stabilizing the operating voltage of a sweep circuit for a cathode-ray tube
AssigneeLicentia Patent-Verwaltungs-G.m.b.H.
InventorOtto Daute
Life of this patent
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Abstract
A circuit for stabilizing the operating voltage across a winding of output transformer of a sweep circuit of a cathode ray tube, including a plurality of current flow paths presenting resistances which are electronically controllable and each connected between a source of operating voltage which may fluctuate in amplitude and a respective one of a plurality of taps connected along the length of the winding, and a system for varying the resistances of the paths in response to changes in the amplitude of the operating voltage in such a manner as to maintain the voltage across the entirety of the winding substantially constant. The circuit is able to utilize inexpensive components while reducing overall energy losses.
Claims13
In a system for producing sweep voltages for deflecting the beam of a cathode-ray tube, which system includes an operating voltage source whose output voltage is subject to amplitude variations, an output transformer having a winding, with one end of the winding being normally connected to the voltage source, a capacitor connecting the one end of the winding to a point of common potential for the system, a plurality of voltage-applying taps connected to the transformer at respectively different distances from the one end of the winding, and a circuit for connecting the operating voltage source to different ones of the taps, depending on the operating voltage amplitude, in order to stabilize the voltage across the transformer, the improvement wherein said circuit comprises:
- a plurality of electronically controllable variable resistance means each connected between said operating voltage source and a respective one of said taps;
- a plurality of diodes, each connected in series with a respective one of said variable resistance means and poled to be conductive in the direction of flow of the sweep voltage-producing operating current;
- and control means connected to control the conductive states of said variable resistance means, as a function of the amplitude of the operating voltage, in a manner such that upon the occurrence of successively lower operating voltage amplitude values, successive ones of said resistance means are rendered conductive in the order of the distance of their respective taps from said one end of said winding, starting from that one of said resistance means connected to that one of said taps which is closest to said one end of said winding.
Dependencies are inferred from the claim text.