Buzzer driving circuit

Abstract

The invention provides a buzzer driving circuit, comprising a voltage stabilizing circuit, a fuse network, an RC oscillator, a frequency divider, a driving NMOS transistor, a freewheeling device and an external capacitor. In which the fuse network, RC oscillator, the supply terminal of the frequency divider are connected to the power supply through a voltage regulating circuit. The output of the fuse network is connected to the RC oscillator, the output of the RC oscillator is connected to the divider. The output terminal of the frequency divider is connected to the grid of the driving NMOS transistor, the source electrode of the driving NMOS transistor is grounded and the drain electrode is connected to the power supply through a freewheeling device, one end of the external capacitor is grounded and the other end is connected to the power supply, and the output terminal of the driving circuit is connected to the drain electrode of the driving NMOS transistor. The invention greatly improves the oscillation frequency stability of the RC oscillator, relatively stabilizes the driving current for driving the NMOS transistor, and avoids the burnout of most logic circuits of the circuitdue to excessive fluctuation of the power supply, which is favorable for preventing the chip from burnout when the power supply line is connected with the ground line.

Description

technical field [0001] The invention relates to the technical field of buzzer driving, in particular to a buzzer driving circuit. Background technique [0002] The traditional buzzer oscillation source generally uses a triode multivibrator circuit. The principle of this circuit is to alternately conduct the triode through the charge and discharge of the resistance and the capacitor. This traditional oscillation circuit has the following disadvantages: the frequency fluctuates with the power supply The change is large, because the devices used in the circuit are discrete devices, so the cost is high. And the kind of buzzer drive circuit made of integrated circuits, such as Figure 6 As shown, there are the following disadvantages: (1) The output frequency of this circuit changes significantly with the fluctuation of the power supply; (2) The eight-stage frequency divider is used in the circuit, which limits the design parameters of the previous RC oscillator, especially Comb...

AI Technical Summary

Problems solved by technology

[0003] The present invention provides a buzzer drive circuit to solve the problems existing in the prior art that the chip is easily burned when the power line and the ground line are reversed, as well as the frequency stability and consistency, and the stability of the driving current, while saving costs

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