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US 2004/0075403 A1Published application
High voltage supply for a picture tube
AssigneeThomson Licensing
InventorsDaniel Lopez, Jean-Paul Louvel, Martin Läufer
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AssigneeThomson Licensing
InventorsDaniel Lopez, Jean-Paul Louvel, Martin Läufer
Estimating the term…
The high voltage supply for a picture tube (T) comprises a high voltage transformer (DST), which generates the anode voltage of the picture tube, and a high voltage module (M) with a switched mode power supply for providing a grid voltage, which is higher than the anode voltage. The output of the high voltage transformer (DST) is coupled to the transformer (TR) of the switched mode power supply, for adding the output voltage of the switched mode power supply to the high voltage of the high voltage transformer. Preferably, the transformer (TR) of the switched mode power supply provides the high voltage isolation, and at least the high voltage part of the module (M) including the transformer is potted with a resin. The high voltage module provides advantageously also an output (3) for a connection to the anode of the picture tube, so that the module can be used with present high voltage transformers, without requiring any modification. The primary side of the switched mode power supply comprises a control stage (9) with adjustable means for setting a specific output voltage of the power supply. In a preferred embodiment, this output voltage is adjustable between 300 and 500 Volts, with respect to the high voltage of the high voltage transformer.
High voltage supply for a picture tube (T), comprising a high voltage transformer (DST) for providing an anode of the picture tube (T) with a voltage (EHTout), the picture tube (T) comprising a grid requiring a voltage (EHTm) being higher than the anode voltage (EHTout), characterized in that the high voltage supply comprises further a module (M) with a switched mode power supply for providing the grid voltage (EHTm), said switched mode power supply comprising a transformer (TR), which is coupled to the output of the high voltage transformer (DST).
High voltage supply according to one of the preceding claims, characterized in that the module (M) comprises an output (EHTm) for providing the anode voltage of the picture tube (T).
High voltage supply according to one of the preceding claims, characterized in that the primary winding (W1) of the transformer (TR) is coupled to a system voltage (Us) of a television receiver, which voltage provides also the start-up voltage for the switched mode power supply.
High voltage supply according to one of the preceding claims, characterized in that the high voltage (EHTin) of the high voltage transformer (DST) is coupled via a first diode (D2) to one end of the secondary winding (W2) of the transformer (TR), and the other end of the secondary winding (W2) is coupled via a second diode (D1) to a capacitor (C1, C2) for providing a stabilized output voltage (EHTm).
High voltage module (M) providing a high voltage (EHTm) for a picture tube T, characterized in that it comprises a switched mode power supply with a transformer (TR) having a primary winding (W1) and a secondary winding (W2), the secondary winding (W2) being provided with an input (8) for a high voltage supply (DST) and the other end of the secondary winding (W2) being coupled to an output (7) for providing said high voltage (EHT in), that the transformer (TR) provides a high voltage isolation, and that at least the high voltage part of the power supply is potted with a resin.
Dependencies are inferred from the claim text.