KR200148544Y1 - Circuit for stabilizating raster centering - Google Patents

Abstract

The present invention relates to a raster sensing stabilization circuit, and a conventional circuit is suitable for a single mode monitor, that is, when the DC driving voltage applied to the variable resistor is constant because the horizontal frequency value is constant. In the multi-mode monitor, as the horizontal frequency changes, the voltage applied to the variable resistor also changes, causing the raster to be displaced. The present invention is a horizontal output unit for generating a sawtooth wave current in the horizontal deflection coil through a switching action to receive the horizontal frequency output from the horizontal drive transformer to solve the conventional problems; A flyback transformer for amplifying the collector pulse voltage of the transistor generated on the primary side by a switching action of the horizontal output unit to a high voltage and outputting the voltage to the CRT, while stepping down and outputting a voltage having an appropriate magnitude; A rectifying and constant voltage unit for receiving a voltage having an appropriate magnitude induced on the secondary side of the flyback transformer and rectifying and smoothing it, and then outputting a voltage different from a DC driving voltage as a reference voltage by a predetermined voltage; Raster centering stability circuit composed of a raster centering adjusting unit for adjusting the position of the raster by adjusting the value of the variable resistor by receiving a constant voltage of the rectifier and the constant voltage unit, and thus a constant voltage at all times. By applying this, the center position of the raster can be stably maintained even if the horizontal frequency is changed in the multi-sync and multi-mode monitors.

Description

Raster Centering Stabilization Circuit

1 is a conventional raster centering circuit diagram.

2 is a waveform diagram of a horizontal deflection current in FIG.

3 is a raster centering stabilization circuit diagram of the present invention.

4 is a diagram showing output waveforms of each part in FIG.

* Explanation of symbols for main parts of the drawings

10: horizontal output unit 20: rectification and constant voltage unit

30: raster centering adjustment unit HDT: horizontal drive transformer

HDY: Horizontal deflection coil HLIN: Horizontal linearity correction coil

20-1,20-2: Constant voltage circuit FBT: Flyback transformer

CRT: CRT VR1: Variable resistor

The present invention relates to the last centering circuit, and in particular, multi-sink and multi-mode monitors, by using a constant voltage IC to supply a constant voltage to the raster centering control unit, it is possible to maintain the center position of the raster even when the horizontal frequency changes. To a raster centering stabilization circuit.

FIG. 1 is a conventional raster centering circuit diagram, which is composed of a transistor Q1, a diode D1, a capacitor C1, C2, a horizontal deflection coil HDY, and a horizontal linearity correction coil HLIN. A horizontal output unit 1 which receives the output signal from the horizontal drive transformer HDT and generates a sawtooth wave current in the horizontal deflection coil HDY through a switching action; A flyback transformer (FBT) and a resistor (R2) for amplifying the collector pulse voltage (Vcp) of the transistor (Q1) generated in the primary coil due to the switching action of the horizontal output unit 1 to a high voltage and outputting it to the CRT. , Consisting of a coil (L1), a diode (D2, D3) and a variable resistor (VR1) is composed of a raster centering adjusting unit (2) that can adjust the center position of the raster by changing the value of the variable resistor (VR1). .

The operation of the conventional raster centering circuit configured as described above will be described with reference to FIG.

Transistor Q1, which receives the horizontal frequency from the horizontal drive transformer HDT, switches. When the transistor Q1 is turned on, the DC driving voltage B + is applied to the primary coil of the flyback transformer FBT. Flows through the transistor Q1 to the ground side.

On the contrary, when the transistor Q1 is turned off, the DC driving voltage B + flows to the horizontal deflection coil HDY through the primary coil of the flyback transformer FBT. This generates a sawtooth current in the horizontal deflection coil HDY.

At this time, if you want to adjust the position of the raster, change the value of the variable resistor VR1, that is, if you want to move the position of the raster to the right, increase the value of the variable resistor VR1 (contact point N1).

Then, the diode D3 is turned on so that the current i1 is the horizontal deflection coil HDY through the resistor R2, the coil L1, the variable resistor VR1, the diode D3 and the horizontal linearity correction coil HLIN. Flows into.

This causes the horizontal deflection current to move upwardly above the midpoint voltage, as shown by the dotted line A shown in FIG. 2, thereby moving the position of the raster to the right.

Conversely, if you want to move the position of the raster to the left, reduce the value of the variable resistor VR1. (Contact N side)

The diode D2 is then turned on so that the current i2 is driven through the horizontal deflection coil HDY, the horizontal linearity correction coil HLIN, the diode D2, the variable resistor VR1 and the coil L1. Flows to the side.

This causes the horizontal deflection current to move downward than the midpoint voltage, as shown by the dotted line B shown in FIG. 2, and thus the midpoint position of the raster to the left. In this way, the position of the raster can be adjusted by changing the value of the variable resistor VR1.

However, such a conventional circuit is suitable for a single mode monitor, i.e., when the DC drive voltage applied to the variable resistor is constant because the horizontal frequency value is constant. As the voltage applied to the variable aberration is also changed, the position of the raster is changed.

The purpose of the present invention is to solve this conventional problem, by using a constant voltage circuit so that the constant voltage is always supplied to the raster center regardless of the horizontal frequency change, so that the center position of the raster can be kept constant. To provide a stuffing centering stabilization circuit.

The raster centering stabilization circuit for achieving the object of the present invention is a transistor (Q1), diode (D1), capacitor (C1, C2), horizontal deflection coil (HDY), horizontal linearity as shown in FIG. A horizontal output unit 10 formed of a correction coil HLIN and a coil L1 and generating a sawtooth wave current in the horizontal deflection coil HDY through a switching action by receiving a horizontal frequency output from the horizontal drive transformer HDT; The collector pulse voltage Vcp of the transistor 01 uttered on the primary side by the switching action of the horizontal output unit 10 is amplified to a high voltage and output to the CRT, while being stepped down to a voltage having an appropriate magnitude. A flyback transformer (FBT); The positive and negative voltages induced and depressed on the secondary side of the flyback transformer (FBT) are inputted and rectified and smoothed by the diodes D2 and D3 and the capacitors C3 and C4, respectively. A rectification and constant voltage unit 20 outputting a predetermined voltage by differenting the DC driving voltage B + by a predetermined voltage by 20-1 and 20-2; The resistor R1-R3, the variable resistor VR1, the capacitors C5 and C6, and the transistors Q2 and Q3 are configured to receive a constant voltage of the rectifying and constant voltage unit 20 to adjust the value of the variable resistor VR1. It consists of a raster centering adjustment unit 30 to adjust the position of the raster by adjusting.

When described in detail with reference to Figure 4 with respect to the operation and effect of the present invention configured as described above.

When the horizontal frequency is output from the horizontal drive transformer HDT, the transistor Q1 switches. When the transistor Q1 is turned on, the DC driving voltage B + is applied to the primary coil of the flyback transformer FBT. Flows through the transistor Q1 to the ground side.

On the contrary, when the transistor Q1 is turned off, the DC driving voltage B + flows to the horizontal deflection coil HDY through the primary coil of the flyback transformer FBT.

This generates a sawtooth current in the horizontal deflection coil HDY.

As a result, the collector pulse voltage Vcp of the transistor Q1 as shown in FIG. 4 (a) generated in the primary coil is amplified to high voltage and supplied to the CRT. do.

On the other hand, the voltage generated on the primary side of the flyback transformer (FBT) is stepped down to a voltage of a suitable magnitude by the rectifying and constant voltage unit 20, the voltage of the positive period with respect to the voltage of the direct current driving voltage (B +) The voltage V1 as shown in FIG. 4 (b) induced at the secondary side contact point P2 of the in flyback transformer FBT is rectified and smoothed by the diode D2 and the condenser C3, and the fourth voltage is increased. It becomes the voltage V1 as shown in FIG. (C), and this is made into a constant voltage again as shown in (d) of FIG. 4 via the constant voltage circuit 20-1, and is output.

On the other hand, the voltage of the negative (-) period as shown in (e) of FIG. 4 induced at the contact point P5 of the flyback transformer FBT is rectified and flattened by the diode D3 and the capacitor C4. This results in a voltage V2 as shown in FIG. 4 (f), which is again output as a constant voltage as shown in FIG. 4 (g) through the constant voltage circuit 20-2.

In this case, even when the horizontal frequency is changed and the voltage induced on the secondary side of the flyback transformer FBT is changed, the constant voltage is always applied to the variable resistor VR1 by the rectifying and constant voltage unit 20.

That is, for example, when the DC driving voltage B + is 100V and the constant voltage circuits 20-1 and 20-2 output a voltage obtained by adding 5V to the reference voltage, they are induced at the connection point P2. The voltage is about 110-115V, which is always output at 105V through the diode D2 and the capacitor C3 and through the constant voltage circuit 20-1.

In addition, the voltage induced at the contact point P5 is about 85-90V, which is always output at 95V through the diode D3 and the capacitor D4 and through the constant voltage circuit 20-2.

In this way, by applying a constant voltage to the variable resistor VR1, the center position of the raster is always constant. If you want to adjust the position of the raster, you can change the value of the variable resistor (VR1).

For example, if you want to move the position of the raster to the right, increase the value of the variable resistor VR1 (contact N1 side). Then, the transistor Q2 is turned on so that the current i1 flows in the directions of the transistor Q2, the resistor R3, the coil L1, the horizontal linearity correction coil HLIN, and the horizontal deflection coil HDY.

As a result, as shown in (h) of FIG. 4, the horizontal deflection current moves upward above the midpoint voltage, and accordingly, the position of the raster moves to the right.

Conversely, if you want to move the position of the raster to the left, reduce the value of the variable resistor (VR1) (contact N2 side). Then, the transistor Q3 is turned on so that the current i2 flows in the directions of the horizontal deflection coil HDY, the horizontal linearity correction coil HLIN, the coil L1, the resistor R3, and the transistor Q3.

As a result, as shown in (h) of FIG. 4, the horizontal deflection current moves below the midpoint voltage, and accordingly, the position of the raster moves to the left.

As described in detail above, the present invention has a constant voltage applied to the raster centering control unit regardless of the horizontal frequency so that the center position of the raster can be stably maintained even in multi-sync and multi-mode monitors in which the horizontal frequency varies. There is.

Claims (1)

A horizontal output unit 10 which receives a horizontal frequency output from the horizontal drive transformer HDT and generates a sawtooth wave current in the horizontal deflection coil HDY through a switching action; A flyback transformer that amplifies the collector pulse voltage Vcp of the transistor 01 generated at the primary side by a high voltage to the CRT and outputs the voltage to a CRT while stepping down to a voltage having a suitable magnitude. (FBT); After receiving the positive and negative voltages of the appropriate magnitude induced on the secondary side of the flyback transformer (FBT), rectifying and smoothing them, respectively, the DC voltage as the reference voltage by the constant voltage circuits 20-1 and 20-2. A rectifying and constant voltage unit 20 outputting a predetermined voltage by differenting the driving voltage B + by a predetermined voltage; Raster centering stabilization, characterized in that consisting of a raster centering adjusting unit 30 for adjusting the position of the raster by adjusting the value of the variable resistor (VR1) by receiving a constant voltage of the rectifying and constant voltage unit 20 Circuit.