Supply circuit for a television receiver
AssigneeInternational Standard Electric Corporation
InventorGerd Dobbert
Life of this patent
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Abstract
A supply circuit for television receivers in which power source isolation is effected via a backward transformer. For the sake of achieving an insusceptibility to interferences, the operating frequency is equal to the line frequency. According to the invention, the supplied energy is controlled by varying the switch-on time during one period of the line frequency, in that the disconnecting time position is changed with the aid of a thyristor switching stage.
Claims7
A supply circuit for a television receiver having a horizontal output stage including means for controlling line sweep and commutation, the energy required by said horizontal output stage being provided by a power source through a controllable supply circuit that isolates the power source from the horizontal output stage, said controllable supply circuit comprising:
- an input transformer having a secondary winding connected to the horizontal output stage for providing the energy required thereby and a primary winding adapted for connection to the power source and being electrically isolated from the secondary winding and the horizontal output stage;
- electronic switch means connected in series with the primary winding of the transformer;
- first switching control means for switching on the electronic switch means as a function of line frequency;
- and
- second switching control means for switching off the electronic switch means as a function of the energy required by the horizontal output stage, whereby the supply circuit provides the horizontal output stage with the required energy from the power source while also electrically isolating the horizontal output stage from the power source.
Dependencies are inferred from the claim text.