JPH01291574A - Vertical output circuit - Google Patents

Abstract

PURPOSE:To sufficiently stabilize an output voltage by feeding back the change component of the output voltage to be impressed on a vertical deflection coil to an amplifier part via a Zener diode. CONSTITUTION:The Zener diode ZD shifts the fluctuation component DELTAV0 of the output voltage V0 as it is, and transmits it to a resistor R4 side. Therefore, it follows that the fluctuation component DELTAV0 is fed back to the terminal 4 of an IC circuit 2. In other words, in the title circuit, since the value of the resistor R4 can be approached that of a resistor R5 by sharing most part of difference between an input voltage Vi and the output voltage V0 by the Zener diode ZD, feedback can be performed without reducing the fluctuation component DELTAV0 remarkably. Since an AC component is transmitted by a capacitor C3 connected in parallel with the Zener diode ZD, the amount of feedback can be increased, Therefore, it is possible to stabilize a vertical deflection output voltage to be impressed on the vertical deflection coil 3 sufficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vertical output circuit in a CRT drive circuit of a television receiver, monitor, or the like.

[Conventional technology]

An example of this type of circuit is the circuit shown in FIG.

This circuit takes in the sawtooth wave voltage input to the input terminal 1 via the capacitor C1, and outputs the vertical amplification output from the rc circuit 2.
This circuit amplifies the signal and applies it to the vertical deflection coil 3.

In this circuit, the output voltage ■0 is applied to the ■terminal of the IC circuit 2 by resistors R1 and R2, and feedback is applied. As the vertical amplification output IC circuit 2, for example, μPC
13781 (is used.

In this circuit, if the variation of the output voltage VO is ΔvO, then (R1+R2) is the feedback amount of the variation.

[Problem to be solved by the invention]

However, in this circuit, the DC component of the output voltage 0 is, for example, 14V, while the DC component of the input terminal Vi is about 0.8V, and therefore the resistors R1 and R2 are
Therefore, the right side of equation (1) is very small (and it is not possible to apply sufficient Jmffl in both DC and AC. Therefore, the output voltage ■ There is a problem in that the stabilization of zero is insufficient, and its variations and drifts become large.

The present invention has been made in view of these points, and an object of the present invention is to provide a vertical output circuit that can sufficiently stabilize the output voltage.

[Means to solve the problem]

To this end, the present invention provides a vertical output circuit in which an input sawtooth wave voltage is amplified in an amplifying section and applied to the vertical deflection coil. I tried to feed it back to the amplification section.

〔Example〕

Examples of the present invention will be described below. FIG. 1 is a diagram showing a circuit of one embodiment. Components that are the same as those in FIG. 2 are given the same reference numerals. In this embodiment, the vertical amplification output I
A series circuit of a resistor R4 and a Zener diode ZD is connected between the ■terminal and ■terminal of the C circuit 2 so that the Zener diode ZD is on the deflection coil 3 side,
A capacitor C3 is connected in parallel to the Zener diode ZD.

In this circuit, the Zener diode ZD has an output voltage Vo
Regarding the variation ΔVo, it is shifted as it is and transmitted to the resistor R4 side, so similarly to the above equation (1), the variation ΔVO is fed back to the ■ terminal of the IC circuit 2 as Become.

Therefore, in this circuit, if the Zener diode ZD bears most of the difference between the input voltage Vi and the output voltage As for the AC component, the capacitor C3 connected in parallel with the Zener diode ZD
is transmitted, so the amount of feedback becomes large.

From the above, the vertical deflection output voltage applied to the vertical deflection coil 3 can be sufficiently stabilized.

Note that capacitor C3 is not necessarily Zener diode Z.
There is no need to connect the Zener diode Z in parallel with D.
A similar effect can be obtained even if it is connected in parallel to the series circuit of D and resistor R4.

〔Effect of the invention〕

As described above, according to the present invention, there is an advantage that sufficient feedback can be applied to both AC and DC, and the output voltage can be highly stabilized.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a vertical output circuit according to an embodiment of the present invention, and FIG. 2 is a conventional circuit diagram of the same. 1... Input terminal, 2... Vertical amplification output IC circuit, 3
...Vertical deflection coil. Agent Patent Attorney Tsuneaki Nagao Figure 1 Figure 2

Claims (2)

[Claims] (1) In a vertical output circuit in which an input sawtooth wave voltage is amplified in an amplifier section and applied to a vertical deflection coil, a change in the output voltage applied to the vertical deflection coil is sent to the amplifier section via a Zener diode. A vertical output circuit characterized by feedback. (2) The vertical output circuit according to claim 1, characterized in that a capacitor is connected in parallel to the Zener diode.