KR20140069821A

KR20140069821A - The horn with overvoltage protect

Info

Publication number: KR20140069821A
Application number: KR1020120137583A
Authority: KR
Inventors: 최상규
Original assignee: 인팩혼시스템 주식회사
Priority date: 2012-11-30
Filing date: 2012-11-30
Publication date: 2014-06-10

Abstract

For protecting the horn product against overvoltage that may occur during the use of the vehicle, such as running or maintenance of the vehicle, when the abnormally high voltage above the set voltage is applied to the horn, the operation of the horn is forcibly stopped. And to provide a horn with a built-in overvoltage shutdown function.
To this end, in the present invention, a current flows through a coil wound around a fixed iron core to magnetize the fixed iron core, pulling the moving iron core, stopping the current flow, and returning the moving iron core back to its original state, Thereby providing a horn having a built-in overvoltage shutoff function for shutting off the current flowing through the coil when a voltage higher than the set voltage is sensed.
Here, the overvoltage protection circuit includes the Zener diode D4 and the transistor Q1, the transistor Q2 and the resistor R2, and the resistor R3, or the OP amplifier IC and the transistor Q4, the resistor R2, The resistor R3, the resistor R10 and the resistor R11 or the comparator IC and the resistor R2, the resistor R3, the resistor R12 and the resistor R13.

Description

{HORN WITH OVERVOLTAGE PROTECT} with built-in overvoltage shutdown function

The present invention relates to a horn for use in generating an alarm sound when a vehicle is in danger of running, and more particularly, to a horn which is not a rated voltage and which, when an excessive voltage is applied, The present invention relates to a horn having an overvoltage shutoff function.

A horn is a warning device that emits a beep sound in the course of a vehicle operation, and is classified into an electric horn and an electronic horn according to its operation mode.

First, as shown in Fig. 1 (a), a coil is wound around a fixed iron core, a switch contact is disposed so that a current can be repeatedly applied to the coil, and a diaphragm coupled with the moving iron core is fixed And the current is repeatedly blocked by the coil while being pulled down by the iron core.

Secondly, as shown in FIG. 1 (B), the electronic horn generates a square wave pulse by the electronic circuit without generating a sound by the same operation as that of the electric horn, but using a contact acting as an electric switch. The semiconductor switch (transistor) conducts only during the ON period according to the operation cycle, and current is repeatedly applied to the coil, thereby causing the diaphragm to vibrate and generate sound.

Among the kinds of horns described above, the electronic horn will be described in more detail with reference to Fig. 1 (B). The electronic horn is composed of a constant voltage circuit, a pulse generating circuit, a switch circuit comprising a transistor, a diaphragm, a coil, And the like. The pulse generating circuit can be constituted by using a timer IC, a CMOS IC, an OP AMP, a pre-programmed CPU IC, or the like, and the current is intermittently And a transistor serving as a switch for allowing the current to flow. The pulse generating IC of the pulse generating circuit is configured to supply power to the constant voltage circuit so as to generate a stable frequency without being affected by variations in the power supply voltage. The current applied to the coil causes the iron core located inside the coil to become an electromagnet to generate vibration, and the voltage applied to the coil is configured such that the battery voltage (B +) of the vehicle flows directly through the coil.

In such a configuration, when an excessive voltage (surge voltage) that may occur during battery charging or operation of the electronic device during use of the vehicle, for example, 24V is supplied, the current flowing in the coil is twice as high as that in the case of 12V, A transistor element that interrupts the current breaks down due to a high current, which causes the horn to fail seriously, failing to perform its original function, and can not make a horn sound when a dangerous situation occurs.

To prevent this, a transistor with a high current capacity can be used, but it is costly and expensive to bear the cost burden

In order to solve the above problems, a protective circuit for detecting an overvoltage is added to an electronic circuit part for operating a horn to detect an overvoltage when an overvoltage is applied, thereby blocking a current flowing through the coil to prevent malfunction of the horn .

In order to solve the above-mentioned problem, in order to solve the above problem, a current flows through a coil wound around a fixed iron core to magnetize the fixed iron core, pulling the moving iron core, stopping current flow, and returning the moving iron core to its original state The horn is provided with a built-in overvoltage shutoff function for shutting off the current flowing through the coil when a voltage higher than the set voltage is sensed.

Here, the overvoltage protection circuit includes the Zener diode D4 and the transistor Q1, the transistor Q2 and the resistor R2, and the resistor R3, or the OP amplifier IC and the transistor Q4, the resistor R2, The resistor R3, the resistor R10 and the resistor R11 or the comparator IC and the resistor R2, the resistor R3, the resistor R12 and the resistor R13.

As described above, according to the present invention, when a high voltage equal to or higher than a predetermined voltage is applied to the electronic horn, the pulse signal for conducting the transistor is bypassed to the ground line to prevent the transistor from operating, It is possible to prevent the breakdown of the transistor when the overvoltage is applied and to prevent the breakdown of the horn.

Fig. 1 is a view showing a conventional horn, in which (a) and (b) show an electric horn and an electronic horn, respectively.
Fig. 2 is a block diagram showing a schematic configuration of the present invention.
3 is an overall circuit diagram of an electronic circuit portion using a zener diode and a transistor as one embodiment of the present invention.
Fig. 4 is a diagram showing a configuration circuit of an overvoltage protection circuit using an op-amp IC. Fig.
5 is a diagram showing a configuration of an overvoltage protection circuit using a comparator IC.

Hereinafter, the present invention will be described in detail by way of examples thereof.

2 is a diagram schematically illustrating one embodiment of the present invention.

The horn of this embodiment includes a fixed iron core 1, a coil 5 wound around the fixed core 1 to magnetize the fixed core 1 when current flows therein, a moving iron core 1 pulled when the fixed core 1 is magnetized 6, a diaphragm 7 for vibrating by the movement of the moving iron core 6 to make a sound, and a switch circuit for supplying current to the coil intermittently.

In the horn of the present invention constructed as described above, when current is intermittently supplied to the coil 5 by the electronic circuit, the fixed core 1 is intermittently magnetized to become an electromagnet. The fixed iron core 1, which has been magnetized to become an electromagnet, pulls the moving iron core 6, and at this time the diaphragm 7 attached to the moving iron core 6 is pulled.

At this time, when the current supplied to the coil 5 is interrupted, the fixed iron core 1 loses its magnetic force. The fixed iron core 1 which has lost its magnetic force is no longer able to pull the moving iron core 6. [ The moving iron core 6 and the diaphragm 7 are returned to their original positions by the restoring force of the diaphragm 7 attached to the moving iron core 6 if the fixed iron core 1 does not pull the moving iron core 6. [

Thereafter, when a current is supplied to the coil 5 again, the fixed iron core 1 is magnetized to pull the moving iron core 6 and the diaphragm 7.

When the current is continuously and intermittently supplied to the coil 5, the fixed iron core 1 is magnetized and is non-magnetized to continuously pull or place the moving iron core 6 and the diaphragm 7. In this process, the diaphragm 7 vibrates and makes a sound.

An electronic circuit for supplying current to the coil 5 is constituted by a switch circuit, an overvoltage protection circuit, a pulse generating circuit, and a constant voltage circuit as shown in Fig.

3 is a diagram specifically showing each circuit of the electronic circuit. Each circuit will be described in detail with reference to FIG.

The pulse generating circuit includes a resistor R6, a resistor R7, a diode D2, a resistor R8, a resistor R9, a capacitor C2, a condenser C2, And a constant voltage circuit C3 for supplying a constant voltage to the generating IC U1 is constituted by a resistor R1, a diode D3 and a capacitor C1, The switch circuit for interrupting the current is constituted by a resistor R4, a resistor R5 and a transistor Q3.

The overvoltage protection circuit of the present invention is composed of a resistor R2, a resistor R3, a zener diode D4, a transistor Q1, and a transistor Q2.

The function of the overvoltage protection circuit in the electronic horn of the above-described electronic horn will be described as follows.

When the voltage higher than the standard voltage of the Zener diode D4 is sensed by detecting the power supply voltage applied to the coil through the diode D1 for preventing the reverse polarity, the Zener diode D4 is in the conductive state, Is applied to the Zener diode D4 through the resistor R2 and is connected to the GND to be changed to the 0V potential.

At the same time, the PNP transistor Q1 is turned on. When the transistor Q1 is turned on, the power supply voltage is supplied to the base terminal of the transistor Q2, which is an NPN type transistor, through the resistor R3 and the emitter and collector terminals of the transistor Q1, . At this time, the oscillation pulse supplied to the G terminal of the transistor Q3 via the resistor R4 is connected to the GND through the collector of the transistor Q2 and the emitter terminal, and the transistor Q3, which supplies the current to the coil, The potential of the G terminal becomes 0 V and turns off so that no more current can flow to the coil. Therefore, the overvoltage does not flow in the switch circuit, and the expensive transistor Q3 is protected.

On the other hand, when a power supply voltage lower than the standard voltage of the Zener diode D4 is supplied, the Zener diode D4 is cut off and the + source voltage is supplied to the base terminal of the transistor Q1 through the resistor R2, Is turned off and the power supply voltage that caused the transistor Q2 to conduct through the emitter of the transistor Q1 and the collector of the transistor Q1 is also cut off so that the transistor Q2 Is also turned off, so that the oscillation pulse causes the transistor Q3 to conduct and intermittently flows the current to the coil.

The function of detecting the overvoltage and automatically cutting off the current flowing through the coil by the function described above can prevent the transistor Q3 from being damaged by the overcurrent flowing in the coil.

As another embodiment, the overvoltage protection circuit may be configured as a circuit centering on the operational amplifier IC and the transistor Q4 as shown in Fig.

In the circuit of this embodiment, the reference voltage can be set to any voltage by voltage distribution based on the ratio of the resistance values of the resistors R2 and R10 and the resistors R3 and R11.

This distributed voltage is applied to the input terminals 2 and 3 of the OP amp IC and compared with each other. When the voltage applied to the terminal 3 is detected high, the + output voltage of the output terminal 1 of the OP amp IC The pulse voltage passing through the transistor Q4 and passing through the resistor R4 is connected to the ground line GND to turn off the switching transistor Q3.

Therefore, when the reference voltage is assumed assuming an overvoltage higher than the reference value, excessive current is prevented from flowing to the transistor Q3 as described above, so that the transistor Q3 is protected.

On the other hand, a reference voltage can be easily set by using a zener diode instead of the resistor R10 and the resistor R11 for voltage distribution.

As another embodiment, the overvoltage protection circuit may be configured as a circuit centering on the comparator IC as shown in Fig. In this case, an open collector circuit (OPEN COLLECTOR circuit) is formed in the comparator IC.

This circuit can set the reference voltage by distributing the voltage by the ratio of the resistance value of each of the resistors R2 and R12 and the resistance of the resistor R3 and the resistor R13.

When the divided voltage applied to the input terminals 2 and 3 of the comparator IC is compared with each other and the voltage applied to the second terminal is detected to be high, the pulse voltage passing through the resistor R4 is outputted to the output terminal 1 And the ground terminal (GND) through the terminal 11 connected to the ground GND to turn off the switching transistor Q3.

When a voltage equal to or higher than the set reference voltage is applied, the transistor Q3 can be protected by preventing current from flowing through the transistor Q3.

In this circuit, a reference voltage can be easily set by using a zener diode instead of the resistor R12 and the resistor R13 for voltage distribution.

1: Fixed iron core
5: Coil
6: Moving iron core
7: Diaphragm

Claims

A current flows through a coil wound on a fixed iron core to magnetize the fixed iron core, pulling the moving iron core, stopping the current flow, and returning the moving iron core to its original state. The oscillating plate attached to the moving iron core vibrates, As a result,
A horn with built-in overvoltage protection function that has an overvoltage protection circuit that cuts off the current flowing in the coil when a voltage higher than the set voltage is detected.

The method according to claim 1,
The overvoltage protection circuit comprises a zener diode D4, a transistor Q1, a transistor Q2, a resistor R2, and a resistor R3.

The method according to claim 1,
The overvoltage protection circuit is a horn with a built-in overvoltage protection function consisting of an op-amp IC, a transistor (Q4), a resistor (R2), a resistor (R3), a resistor (R10) and a resistor (R11).

The method according to claim 1,
The overvoltage protection circuit is composed of a comparator IC and a horn with built-in overvoltage shutdown function consisting of a resistor (R2), a resistor (R3), a resistor (R12) and a resistor (R13).