Television receiver supply circuit
AssigneeIndesit Industria Elettrodomestici Italiana S.p.A.
InventorFrancesco Marino
Life of this patent
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Abstract
A television receiver supply circuit includes a transistor driven between saturation and cut off periodically to chop the B+ voltage. The pilot pulses are derived from a pilot pulse source such as flyback pulses on a winding of the line output transformer. To prevent parasitic oscillations a second transistor is provided to ensure that the impedance seen by the winding of the line output transformer remains substantially constant during the flyback pulses.
Claims9
In a television receiver having a load circuit, a d.c. supply voltage source, and a pilot pulse source, a supply circuit including a first transistor responsive to the pulses from the pilot pulse source to be switched between saturation and cut off so as to conduct current periodically from the supply voltage source to the load circuit, the improvement comprising connecting means arranged between the first transistor and pilot pulse source and operative to maintain the impedance at the output of the pilot pulse source substantially constant during the operating cycle of the supply circuit .
A television receiver supply circuit according to any one of the preceding claims, wherein the said pilot pulses are repeated at line scanning frequency and the said pilot pulse source consists of an additional winding of the line deflection stage output transformer.
Dependencies are inferred from the claim text.