JPS60208790A - Horizontal amplitude stabilizing circuit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to a display horizontal amplitude stabilization circuit for signal sources with various horizontal synchronization frequencies, such as computers.

Conventional configuration and its problems In recent years, computers have developed significantly and have become familiar. Along with this, displays for displaying computer contents have also become highly developed. However, since the horizontal synchronization frequency of computers varies depending on the model, there is a problem in that it is necessary to prepare one display for each model.

Purpose of the Invention The present invention solves the above-mentioned conventional problems.The present invention is aimed at solving the above-mentioned conventional problems. The purpose is to provide an amplitude stabilization circuit.

Structure of the Invention The horizontal amplitude stabilizing circuit of the present invention includes a horizontal output circuit having a horizontal deflection coil, a current flowing through the horizontal deflection coil that changes according to a horizontal synchronization frequency, and detecting a current that changes according to the magnitude of the current. a horizontal amplitude detection circuit that feeds back an electrical signal to a power supply circuit; and an output voltage of the horizontal output circuit so as to maintain a horizontal amplitude substantially constant in response to the feedback electrical signal inputted from the horizontal amplitude detection circuit. It is equipped with a variable power supply circuit.

According to this configuration, if this horizontal amplitude stabilization circuit is installed in one display, a constant horizontal amplitude will always be obtained even when connected to a computer with any horizontal synchronization frequency, and a stable image will be produced. It can be projected.

DESCRIPTION OF THE EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. 1 to 4. FIG. 1 is a block diagram showing a double line fishing configuration, and shows a power supply circuit A, a horizontal output circuit B, and a horizontal amplitude detection circuit C.

FIG. 2 shows a horizontal output circuit and a horizontal amplitude detection circuit. The sawtooth wave current flowing through the horizontal deflection coil L1 and resistor R1 is converted into voltage by the resistor R1, amplified by transistors Ql and Q2, rectified and smoothed by diodes DI and D2 and capacitors C1 and C2, and then applied to the horizontal deflection coil. The magnitude of the sawtooth wave current flowing through L1 is fed back to the power supply circuit. Q is a horizontal output transistor.

FIG. 3 shows a power supply circuit A, which uses an AVR.

In Fig. 3, the 12 points are connected from the 'r'2 point in Fig. 2, a voltage corresponding to the horizontal amplitude is input from the horizontal amplitude detection circuit C, and the base voltage of the transistor Q3 is changed via the transistor Q2. to change the output voltage at point T1.

For example, as shown in FIG. 4A, when the output voltage of the power supply circuit A is constant, as the horizontal synchronization frequency increases, the amplitude of the sawtooth wave current flowing through the horizontal deflection coil L1 becomes smaller. As the amplitude becomes smaller, the voltage at the 12 points in FIG. 2 becomes lower. In other words, the voltage at point 12 in Figure 3 decreases, the collector current of transistor Q2 decreases, the base voltage of transistor Q3 increases, the output voltage at point T1 also increases, and finally as shown in Figure 4 (B). Obtain sawtooth currents of the same amplitude as shown in .

In FIG. 4, the solid line represents the case where the horizontal synchronization frequency is low, and the broken line represents the case where the horizontal synchronization frequency is twice that of the solid line.

A second embodiment will be explained based on FIG. This shows a power supply circuit A using a switching regulator. 1st
The voltage applied to the <72 point as in the example of
4. The duty of the switching waveform applied to the base of transistor Q6 via Q5 is changed, and the output voltage at point T1 is changed via transistor Q8 and transformer T.

In this case, as in the first embodiment, when the voltage at 12 points decreases, transistor Q4. The collector current of transistor Q5 decreases and the collector current of transistor Q6. Q7. By lengthening the ON time of QB, the output voltage of the transformer T is increased, and the waveform shown in FIG. 4(B) is obtained.

Effects of the Invention As described above, according to the present invention, even if a single display with a horizontal amplitude stabilization circuit is connected to a computer or the like with any horizontal synchronization frequency, stable images can be received. effective.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of the basic configuration of the first embodiment of the present invention, Fig. 2 is a circuit diagram showing the power supply circuit in blocks, and specifically showing the horizontal output circuit and horizontal amplitude detection circuit. 4 is a circuit diagram of the power supply circuit, FIGS. 4A and 4B are operation waveform diagrams, and FIG. 5 is a circuit diagram of the power supply circuit of the second embodiment.

Claims (1)

[Claims] a horizontal output circuit having a horizontal deflection coil; and a horizontal amplitude detection circuit that detects a current flowing through the horizontal deflection coil and varying according to a horizontal synchronization frequency and returns an electric signal corresponding to the magnitude of this current to a power supply circuit. and a power supply circuit that changes the output voltage of the horizontal output circuit in response to the feedback electrical signal input from the horizontal amplitude detection circuit so as to maintain the horizontal amplitude substantially constant. .