Motor vehicle electronic horn and motor vehicle electronic horn protection method

Abstract

The invention relates to a motor vehicle electronic horn and a motor vehicle electronic horn protection method. The method comprises the steps of determining whether the working voltage of the motor vehicle electronic horn exceeds a rated operational voltage; and controlling a horn driving signal when the overvoltage exceeds the rated operational voltage. The motor vehicle electronic horn comprises: a detection unit for detecting whether the overvoltage exceeds the rated operational voltage; and a control unit for controlling the horn driving signal when the overvoltage exceeds the rated operational voltage. According to the invention, when the motor vehicle electronic horn is in large voltage disturbance condition, by controlling the horn driving signal, the breakdown of the horn power driving tube can be avoided, and the motor vehicle electronic horn can be effectively protected.

Description

technical field [0001] The invention relates to the field of motor vehicle electronic horns, in particular to a motor vehicle electronic horn and a method for protecting the motor vehicle electronic horn. Background technique [0002] At present, automotive electronic horns are favored by the automotive industry due to their long life and low electromagnetic radiation. However, due to the electromagnetic interference generated by the ignition system and various motor relays in the automotive power supply, it has a greater impact on the life and reliability of the automotive electronic horn. However, due to the limitation of cost and its own volume, automotive electronic horns cannot be installed with devices such as relatively complex regulated power supplies or DC--DC converters to protect the work safety of the horns. [0003] Speaker power output tubes generally use transistors, field effect tubes, IGBT tubes, etc. For example, an electronic horn working at 12V in a car...

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Problems solved by technology

For example, an electronic horn working at 12V in a car sometimes has to withstand hundreds of volts of overvoltage, but because the overvoltage pulse width is very narrow, generally a simple absorption protection circuit can do the job, but it encounters a large one like 5b in the ISO7637EMC specification Width pulse overvoltage (up to hundreds of milliseconds) will cause the instantaneous current of the power drive tube in the electronic horn to reach nearly 100 amperes, and the strong back electromotive force generated by the horn drive coil will easily break down and burn the power drive tube and cause the speaker to fail damage

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