KR0119971Y1 - Horizontal deflection circuit of tv - Google Patents

Abstract

The object of the present invention is a horizontal deflection circuit of a TV (TV) which can drive the SCR and FET with the output of the drive transistor by configuring a horizontal output circuit with SCR and FET in the horizontal deflection circuit. Is a cathode of the cathode ray tube by the first switching means switched according to the input horizontal oscillation waveform, the second switching means switched according to the switching of the first switching means, and the sawtooth current input according to the switching of the second switching means. It is achieved by constructing a horizontal deflection circuit of the TV (TV), characterized in that it comprises a horizontal deflection means for deflecting the beam emitted from the left and right.

Description

TV's horizontal deflection circuit

1 is a block diagram of a horizontal deflection circuit of a conventional TV.

2 is a schematic circuit diagram of FIG.

3 is an input / output waveform diagram of each part of FIG. 2;

4 is a block diagram of a horizontal deflection circuit of the present invention TV.

5 is a schematic circuit diagram of FIG.

6 is a waveform diagram of input and output parts of FIG.

* Explanation of symbols for main parts of the drawings

1: horizontal oscillation unit 2: first switching unit

3: second switching unit 4: first charging / discharging unit

5 horizontal deflection portion 6 second charge and discharge portion

The present invention relates to a horizontal deflection circuit of a TV, and in particular, in a horizontal deflection circuit, a silicon controlled rectifier (abbreviated as SCR) and a field effect transistor (abbreviated as FET) are horizontal. The present invention relates to a horizontal deflection circuit of a television (TV) that constitutes a deflection circuit so as to drive an SCR and an FET with an output of a drive transistor.

As shown in FIGS. 1 and 2, a horizontal deflection circuit of a conventional TV includes a horizontal oscillation circuit 10 for generating a switching pulse which is the basis of horizontal deflection and high voltage generation, and the horizontal oscillation circuit ( A first switching unit 20 composed of a horizontal drive transistor Q1, a resistor R1, and a capacitor C1, which is switched by a horizontal oscillation waveform outputted from 10), and the switching of the first switching unit 20; Therefore, a horizontal drive transformer 30 for inducing a power supply Vcc, a resistor R3 for switching the voltage output through the horizontal drive transformer 30, a horizontal output transistor Q2, and a damper diode D1. A first charging and discharging unit 50 comprising a second switching unit 40, an S-shaped capacitor C3 charging and discharging a voltage according to the switching of the second switching unit 40, and the first charging and discharging unit ( Horizontal deflection coil L for horizontal deflection by sawtooth current according to voltage output from 50) The horizontal deflection unit 60 and the resonant capacitor C2 for charging and discharging the voltage output from the horizontal deflection unit 60 by the second switching unit 40 to the second charge and discharge unit 70, The flyback transformer 80 is configured to induce a horizontal output pulse output from the second charging and discharging unit 70 to output a DC voltage to the anode of the CRT.

The horizontal deflection circuit of the conventional TV configured as described above will be described in detail with reference to FIG. 3. The horizontal oscillation drive waveform output from the horizontal oscillation circuit 10 is represented by t1 in FIG. 3A. When the high signal is applied for t3 hours and the base of the horizontal drive transistor Q1 in the first switching unit 20 is applied, the horizontal drive transistor Q1 is turned on by the horizontal oscillation drive waveform from the horizontal oscillation circuit 10. do.

As the horizontal drive transistor Q1 is turned on, the power supply Vcc is grounded through the resistor R2, the primary winding of the horizontal drive transformer T, and the emitter of the horizontal drive transistor Q1.

Accordingly, a low signal is applied to the base of the horizontal output transistor Q2 in the second switching unit 40 for a time t3 to t3 shown in FIG. 3C, and the horizontal output transistor Q2 is turned off.

As the horizontal output transistor Q2 is turned off, the power supply B + is sequentially passed through the primary winding of the flyback transformer 80 and the horizontal deflection coil L of the horizontal deflection buoy 60B. S-shaped condenser (C3) of the charge and the charged power (B +) is charged in the resonant capacitor (C2) of the first charge and discharge unit 70 through the horizontal deflection coil (L) of the horizontal deflection unit 60. do.

When the recharging of the resonant capacitor C2 of the second voltage charging unit 70 is completed, the discharge is performed, that is, the instantaneous resonant pulse voltage between the time t1 and t2 shown in FIG. Induced by the secondary winding of 80 provides high pressure to the anode of the CRT.

On the other hand, since the counter electromotive force generated in the horizontal deflection coil L in the horizontal deflection portion 60 is greater than the power B + charged in the S-shaped condenser C3 during the period t2 to t3, the damper diode of the second switching 40 (D1) is turned on so that the current shown in (e) of FIG. 3 flows, and the sawtooth wave current wave shown in (g) of FIG. 3 flows through the horizontal deflection coil (L).

On the other hand, when the horizontal deflection drive waveform output from the horizontal oscillation circuit 10 is applied to the base of the horizontal drive transistor Q1 of the horizontal drive circuit 20 by outputting a low signal for t4 time from t3 shown in FIG. The horizontal drive transistor Q1 is turned off by the signal output from the horizontal oscillation circuit 10.

At this time, the fib component of the counter electromotive force generated in the collector of the horizontal drive transistor Q1 shown in (b) of FIG. 3 is shaped by the resistor R1 and the capacitor C1.

As the horizontal drive transistor Q1 is turned off, a voltage for driving the horizontal output transistor Q2, that is, a high voltage shown in (c) of FIG. 3 is horizontally driven through the drive transformer T1 and the resistor R3. The horizontal output transistor Q2 is turned on by being applied to the base of the output transistor Q2.

As the horizontal output transistor Q2 is turned on, the collector current of the horizontal output transistor Q2 flows through the current shown in (d) of FIG. 3 and the sawtooth wave shown in (d) of FIG. 3 in the horizontal deflection coil L. Current will flow.

As such, a sawtooth current flows between the horizontal deflection coils L between the syringes t2 to t4 so that the electron beam emitted from the electron gun of the CRT is deflected on the screen.

However, such a conventional TV deflection circuit uses a power transistor as a switching element for passing a sawtooth current to a horizontal deflection coil, thus requiring a horizontal drive transformer, a base current regulating resistor, and a capacitor. Accordingly, there is a problem in that heat generation of the power transistor is increased.

Therefore, an object of the present invention is to provide a horizontal deflection circuit of a TV (TV) which can drive the SCR and FET with the output of the drive transistor by configuring the horizontal output circuit with the silicon controlled rectifier and the field effect transistor in the horizontal deflection circuit. .

As described above, an object of the present invention is to provide a first switching means switched according to an input horizontal oscillation waveform, a second switching means switched according to the switching of the first switching means, and an input according to the switching of the second switching means. It is achieved by constructing a horizontal deflection circuit of a TV (TV), characterized in that it comprises a horizontal deflection portion which causes the beam emitted from the cathode of the cathode ray tube to be deflected from side to side by a sawtooth wave current. With reference to the following in detail.

4 and 5 are horizontal deflection circuits of the present invention TV, as shown therein, a horizontal oscillation circuit 1 for generating a pulse for a switch which is the basis of horizontal deflection and high voltage generation, and the horizontal A first switching unit 2 comprising a horizontal drive transistor Q1 switched by a horizontal oscillation waveform output from the oscillation circuit 1, an SCR, a FET switched according to the switching of the first switching unit 2, and A second switching unit 3 made of a damper diode D1, a first charging and discharging unit 4 for charging and discharging a voltage input according to the switching of the second switching unit 3, and the first charging and discharging unit A horizontal deflector 5 for horizontal deflection by a sawtooth wave current corresponding to the voltage output from (4) and a voltage output from the horizontal deflector 5 by switching of the second switching part 3 Horizontal output pulses output from the second charge / discharge unit 6 and the second charge / discharge unit 6 The organic was composed of a flyback transformer (7) for outputting a DC voltage to the cathode-ray tube anode.

Referring to Figure 6 attached to the operation and effects of the present invention configured as described above are as follows.

The FET that replaces the horizontal output TR in this design is designed for high breakdown voltage and high current, and it is possible to replace the transformer because the impedance between input and output which is inherent in the FET is large.

In the prior art, the horizontal output transistor has a high breakdown voltage characteristic and excellent frequency characteristic because a flyback voltage (B +) is applied. Therefore, in order to configure a horizontal output circuit as FE, it is necessary to replace these characteristics. In this design, high voltage is divided into FET and SCR, so it can be replaced.

Of course, to withstand the high voltage that occurs instantaneously, both devices must have a high internal voltage.

In order to withstand a certain period of time even with a high voltage instantaneously, the partial pressure of the two elements is necessary.

Under such a background, the horizontal oscillation drive waveform outputted from the horizontal oscillation circuit 1 becomes a high signal for t3 time from t1 shown in FIG. 6A, so that the horizontal drive transistor Q1 in the first switching section 2 is turned off. When applied to the base, the horizontal drive transistor Q1 is turned on by the horizontal oscillation drive waveform output from the horizontal oscillation circuit 1.

As the horizontal drive transistor Q1 is turned on, the power supply Vcc is sequentially grounded through the resistor R1 and the emitter of the horizontal drive transistor Q1.

Accordingly, a low signal is applied to the gate voltages of the field effect transistor (FET) and the silicon control rectifier (SCR) of the second switching 3 during the time t1 to t3 shown in FIG. 6B. ) Is off.

As the field effect transistor (FET) is turned off, the drain current of the field effect transistor (FET) and the anode current of the silicon controlled rectifier (SCR) are blocked for t3 time from t1 shown in FIG. Rectifier SCR is turned off.

Accordingly, the power source B + is sequentially supplied to the S-shaped correction capacitor C2 of the first charge / discharge unit 4 through the primary winding of the flyback transformer 7 and the horizontal deflection coil L of the horizontal deflection unit 5. The charged power B + is charged in the resonant capacitor C1 of the second charge / discharge unit 6 through the horizontal deflection coil L of the horizontal deflection unit 5.

After charging is completed in the resonant capacitor C1 of the second charge / discharge unit 6, the resonant pulse voltage is induced to the secondary winding of the flyback transformer 7 to provide high pressure to the anode of the CRT.

In addition, since the counter electromotive force generated in the horizontal deflection coil L of the horizontal deflection portion 5 during t2 to t3 time is larger than the power B + charged in the S-shaped correction capacitor C2 of the second charging / discharging portion 6. The damper diode D1 of the second switching unit 3 is turned on so that a current flows, and a sawtooth wave current shown in FIG. 6D flows through the horizontal deflection coil L. FIG.

Thereafter, when the horizontal oscillation drive waveform output from the horizontal oscillation circuit 1 is outputted to the base of the horizontal drive transistor Q1 of the first switching unit 2 when a low signal is output for a time t4 at t3 shown in FIG. The horizontal drive transistor Q1 is turned off by the low signal output from the horizontal oscillation circuit 1.

As the horizontal drive transistor Q1 is turned off, the gate of the field effect transistor FET and the silicon rectifier controller SCR of the second switching unit 3 becomes high for a period t4 to t4 shown in (b) of FIG. 6. The voltage is applied to turn on the field effect transistor (FET).

As the field effect transistor (FET) is turned on, the current in the period t3 to t4 shown in (c) of FIG. 6 sequentially moves the source of the field effect horizontal deflection circuit (FET), the anode of the silicon controlled rectifier (SCR), and the cathode. Grounded through.

Accordingly, the sawtooth wave current shown in (d) of FIG. 6 flows through the horizontal deflection coil L. FIG.

As such, a sawtooth current flows between the horizontal deflection coils L between the syringes t2 to t4 so that the electron beam emitted from the electron gun of the CRT is deflected to the left and right of the screen.

As described in detail above, the present invention can reduce the drive power and simplify the drive circuit by driving the gates of the SCR and the FET to the output of the drive transistor using the SCR and the FET as the switching elements of the horizontal output circuit. There is an effect that can easily control the effect and the switching element.

In addition, the horizontal transformer occupies a large volume, and the present invention reduces the volume by using a FET instead of the transformer. It also reduces power T's power consumption by using FETs. Unlike power TR, which is a drive switch driven by current, FET is a drive switch driven by voltage, thereby saving power.

Conventionally, since the heat generation of the power transistor is increased in accordance with the demand of the drive power, the reliability is lowered, but in the present invention, even if a small current flows compared to the power transistor, the reliability can be ensured.

In addition, the drive circuit can be simplified, and the semiconductor can be easily formed by using the MOS device and the SCR device. Conventionally, the inefficient aspect of the horizontal deflection circuit is effectively implemented, and the structure is simple, the efficiency is good, and the IC is easy to effect.

Claims (1)

Silicon control for outputting a sawtooth current by first switching means switched according to an input horizontal oscillation circuit, and a field effect transistor controlled primarily by the switching of the first switching means, and a second effect controlled by the switching of the field effect transistor. Second switching means comprising a rectifier. And horizontal deflection means for deflecting the beam emitted from the cathode of the cathode ray tube to the left and right by the sawtooth wave current inputted by the switching of the second switching means.