KR940017706A - Supply voltage control circuit of multi-mode monitor - Google Patents

Abstract

The present invention relates to a power supply voltage control circuit of a multi-mode monitor that supplies a stabilized power supply by varying the power supplied to the monitor (anode supply high voltage) according to various horizontal frequencies in a multi-sync mode monitor. will be.

Since the conventional monitor high voltage application circuit cannot cope with the change in the horizontal frequency, when the horizontal frequency is increased, the high voltage is lowered, which causes distortion of the image.

The present invention detects a change in the horizontal frequency of a multi-mode monitor and varies the power level applied to the flyback transformer according to the detection result, thereby supplying the high voltage supplied to the monitor anode from the secondary side of the flyback transformer. It can be stabilized and supplied regardless of changes, and it is possible to secure a uniform horizontal deflection and prevent distortion of the screen. It is applied to a multi-sync monitor.

Description

Supply voltage control circuit of multi-mode monitor

Since this is an open matter, no full text was included.

2 is a block diagram of a power supply voltage control circuit of a multimode monitor of the present invention, and FIG. 3 is a block diagram of an embodiment of a power supply voltage control circuit of a multimode monitor of the present invention, and FIG. 4 is a block diagram of a multimode monitor of the present invention. 5 is a signal waveform diagram showing an operation relationship of a circuit of the present invention according to each mode.

Claims (6)

A duty / time detection signal 4 for outputting a detection signal corresponding to the pulse width of the horizontal driving pulse as duty information corresponding to the horizontal frequency change, and an output signal of the duty / time detection means 4 as a flyback transformer ( A duty control means (5) for varying the power duty to suit the horizontal horizontal frequency which is varied compared to the secondary power supply detection signal (H / V Det) of the FBT) and an output signal of the duty / time detection means (4) Supplying power of the flyback transformer (FBT) to the initial start means 6 for detecting the initial start and controlling the initial start operation of the duty control means 5 and the power output of the duty ratio being changed by the duty control means 5. A power supply voltage control circuit of a multi-mode monitor, comprising power conversion means (7) for converting and outputting (B +) levels. The differential / time detection signal (4) according to claim 1, characterized in that the duty / time detection signal (4) comprises: a differentiator (4A) for differentiating a horizontal drive pulse, a constant current source (4B) for supplying a stable constant current power to the differential signal, Power supply voltage control of a multi-mode monitor comprising a synthesis section 4C for synthesizing the constant current power supply, an integrator 4D for integrating the synthesized signal, and a level limiting section 4E for limiting the highest upper limit level of the integrated signal. Circuit. The amplification unit as claimed in claim 1, wherein the duty control means (5) comprises: a comparison unit (5A) for comparing the duty / time detection signal and the power detection signal (H / V Det), and amplifying the signal output as a result of the comparison. A power supply voltage control circuit of a multi-mode monitor comprising a section (5B) and an output section (5C) for outputting an amplified signal to a rear stage. 2. The power supply detection signal (H /) of the duty control means (5) according to claim 1, wherein the initial start means (6) comprises: a delay portion (6A) for delaying the duty / time detection signal by a predetermined time; V Det) The power supply voltage control circuit of the multi-mode monitor consisting of a switching unit 6B for controlling the input. The power supply conversion unit (7) according to claim 1, wherein the power conversion unit (7) includes a DC / DC conversion unit (7A) for converting and outputting a power supply signal having a duty ratio corresponding to the input power duty control signal, and the converted power supply signal. Voltage control circuit of a multi-mode monitor consisting of a smoothing part (7B) which outputs a flyback transformer (FBT) to a power supply (B ⁺ ) by smoothing DC to DC. 3. The method of claim 2, wherein the differentiator 4A is composed of a capacitor C2 and a resistor R4 for differentiation of an input signal, and the constant current source 4B is a zener diode ZD1 and a diode for constant power supply. (D2) and a transistor (Q2) for flowing a constant current according to the voltage set by the zener diode (ZD1) and diode (D2), and the synthesis section (4C) is supplied by the constant current power is switched by the differential signal The integrator 4D is composed of a capacitor C3 charged / discharged by the transistor Q3, and the level limiter 4E sets the upper limit level of charging of the capacitor C3. Power supply voltage control circuit of multi-mode monitor composed of Zener diode (ZD2). ※ Note: The disclosure is based on the initial application.