Wideband triangular wave control system based on step-down type constant current

Abstract

The invention discloses a broadband triangular wave control system based on linear driving. The system is mainly composed of a front-end power circuit, a protection circuit, a resonance circuit, a comparison circuit, a trigger circuit and a triangular wave control circuit, wherein the protection circuit is connected with the output end of the front-end power circuit, the comparison circuit and the trigger circuit are connected with the resonance circuit, and the triangular wave control circuit is connected with the trigger circuit. The system is characterized in that a linear driving circuit is further connected between the protection circuit and the resonance circuit; the linear driving circuit is composed of a driving chip U3, a triode VT5, a triode VT6, a triode VT7, a triode VT8, a polar capacitor C11, a resistor R22, a polar capacitor C13 and the like; the positive electrode of the polar capacitor C11 is connected with the protection circuit, and the negative electrode of the polar capacitor C11 is connected with a pin IN1 of the driving chip U3 after passing through a resistor R21; one end of the resistor R22 is connected with the collector electrode of the triode VT5, and the other end of the resistor R22 is connected with the base electrode of the triode VT7 after passing through a resistor R23; the positive electrode of the polar capacitor C13 is connected with the base electrode of the triode VT5, and the negative electrode of the polar capacitor C13 is connected with the pin IN1 of the driving chip U3. Since the broadband triangular wave control system based on linear driving is provided with the linear driving circuit, the stability of the control system can be higher.

Description

technical field [0001] The invention relates to the field of electronics, in particular to a wide-frequency triangular wave control system based on a step-down constant current. Background technique [0002] With the continuous development of science and technology, a large number of electronic products such as TVs and computers have appeared in people's lives. Triangular wave scanning circuits are used in TV screens, computer monitors and other display devices. However, the current general triangular wave system uses an analog circuit to charge a capacitor through a constant current source to generate a linear triangular wave voltage. Due to the interference of this kind of circuit, the voltage and current of the circuit are also very unstable, and different degrees of nonlinear distortion will be generated at the beginning and top positions of the triangular wave voltage. In order to overcome this nonlinear distortion, a bootstrap circuit is usually added, but the bootstr...

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Problems solved by technology

[0003] The purpose of the present invention is to overcome the defects of the current triangular wave control system such as low voltage amplitude, low power utilization rate, unstable voltage and current, and low frequency, and provide a wide-band triangular wave control system based on step-down constant current

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