Samsung Electronics Co., Ltd.

Joong-Yeol Kwon

Hideki Kofune

Sang-Young Lee

Jung-Hyun Ahn

Kil-Soo Park

Disclosed is a power-supplying apparatus for an electron gun in a color display tube (CDT) provided with an fly back transformer (FBT) having a focus voltage output terminal and an acceleration voltage output terminal, further having a power supplying part supplying a predetermined reference voltage; a focus voltage detection part detecting a focus voltage of the focus voltage output terminal; and a focus voltage boost part boosting the focus voltage of the focus voltage output terminal in case that the focus voltage detected by the focus voltage detection part is lower than the reference voltage of the power supplying part. With this configuration, it is possible to recover the voltage of the focus voltage output terminal dropped according to the grid discharging of the electron gun in the color display tube to the normal voltage.

Power supplying apparatus for electron gun in CDT

A current variable inductor having closed loop characteristics and a horizontal linearity compensation circuit. The current variable inductor having the closed loop characteristics is constructed with the legs of the first E-shaped core and the legs of the second E-shaped core extend toward each other, an I-shaped core is arranged between the first E-shaped core and the second E-shaped core such that the I-shaped core is in contact with the first E-shaped core, and the I-shaped core is spaced apart from the second E-shaped core. A primary coil is wound around a center leg of the first E-shaped core and a secondary coil is wound around a center leg of the second E-shaped core. A magnetic flux generated from the primary coil is cut due to the magnetic resistance characteristics of the I-shaped core to vary the inductance of the secondary coil, to thereby form enclosed loops of magnetic flux inside the first and second E-shaped cores, respectively.

Electric current variable-type inductor having closed loop characteristics and a horizontal linearity compensation circuit

A horizontal deflection output circuit has a resonance circuit including a horizontal deflection yoke for generating the horizontal deflection signal, a first switch element, a second switch element comprising a bipolar transistor, and a circuit for applying a reverse bias voltage to the emitter-base junction of the bipolar transistor during a retrace period to remove excess minority carriers stored in its base rapidly, thereby making high speed switching operation of the transistor possible.

Horizontal deflection output circuit for high-frequency horizontal

A high voltage generation circuit incorporates the horizontal circuit of a cathode ray tube (CRT) monitor. The horizontal circuit comprises a horizontal output transistor, a retrace capacitor coupled in parallel with the horizontal output transistor, a damping diode which clamps the minimum voltage at the drain of the transistor to approximately ground potential, and a flyback transformer. The primary winding of the flyback transformer is coupled between a terminal where a DC power supply B+ is applied and the drain of the horizontal output transistor. A second transformer is provided between the retrace capacitor and the ground for producing a voltage at the secondary winding thereof each time a free oscillation occurs between the damping interval Td of the damper diode and the conduction interval Ton of the horizontal output transistor. A diode is also provided for rectifying the voltage produced at the secondary winding of the second transformer, and thus the energy stored in the retrace capacitor is returned to the power supply B+ as a return current. Further included is an error detector for comparing a DC voltage detected at the secondary winding of the first transformer with a reference voltage to produce an error detect signal; and a pulse width modulator for supplying a pulse-width modulated signal to the base of the horizontal output transistor, causing it to perform a switching operation in response to the error detect signal fed from the error detector. Preferably, the second transformer has a predetermined turns ratio between the primary and secondary windings thereof such that the voltage at the secondary winding may be such as to allow the diode Drg to be in the cut-off region at the discharge of the retrace capacitor if the retrace capacitor Cr is charged to a value more than one-half of the supply voltage.

Stabilized high voltage generation circuit for cathode ray tube display

A horizontal deflection S-type correction circuit a transformer connected in series to a S-typed correction capacitor that is serially coupled to a horizontal coil of a deflecting yoke and a resistor for detecting deflection current. The resistor is coupled in series with the secondary winding of a first part of the transformer. A differential amplifier is coupled to the primary winding of a second part of the transformer and a double balanced modulator is connected between the resistor and the differential amplifier.

Horizontal deflection S-typed correction circuit

A high voltage stabilizing circuit includes: an error amplifier for receiving a flyback pulse rectified from one secondary side coil of a flyback transformer at an inverting terminal thereof and for receiving a reference voltage at a non-inverting terminal thereof, and for comparing the received inputs; a pulse width modulator for implementing a modulating operation in accordance with an output signal of the error amplifier and for simultaneously generating an output signal which is synchronous with the flyback pulse; a switching unit for performing a switching operation in accordance with the output signal of the pulse width modulator; and an auxiliary transformer having a primary side coil to which an output signal of the switching unit is supplied and a secondary side coil which is connected in parallel to another secondary side coil of the flyback transformer, for producing an output pulse corresponding to the flyback pulse outputted from the flyback transformer.

High voltage stabilizing circuit

Disclosed is a horizontal deflection output circuit for providing a horizontal deflection signal to a deflection yoke of a cathode ray tube to horizontally deflect electron beams in accordance with the horizontal deflection signal, the horizontal deflection output circuit having a switching transistor responsive to a horizontal output driving pulse signal applied at its base, an emitter of the switching transistor being connected to a ground terminal, a deflection yoke coupled between a first node at a collector of the switching transistor and a second node, a S-deflection distortion correcting capacitor coupled between the second node and the ground terminal, and a dampening diode and a retrace capacitor coupled in parallel between the first node and the ground terminal, the horizontal deflection output circuit comprising, a choke coil connected between a voltage source and the second node, the choke coil reducing power loss in the horizontal deflection output circuit and providing a power loss current indicative of the power loss to the deflection yoke, and a raster position correcting circuit coupled between the first node and the second node, the raster position correcting circuit providing a correction voltage to the first node for correcting a distorted raster position caused by a DC signal corresponding to the power loss current during a trace interval.

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Suwon, South Korea

Joong-Yeol Kwon