JPH0560952U - Mute circuit for car audio system - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] A mute circuit for an in-vehicle audio device that mutes or attenuates the audio signal of the in-vehicle audio device simply by opening the door when a vehicle passenger gets on or off. Is provided. [Constitution] An ON / OFF signal of a vehicle door switch 3 is connected to a mute signal input terminal 4 of an on-vehicle audio device 5 or to a relay coil of a mute unit constituted by a relay for short-circuiting a resistor. The mute operation is turned on / off by opening and closing.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a mute circuit for an on-vehicle audio device, and more particularly to a mute circuit for an on-vehicle audio device that is suitable for automatically performing a mute operation by opening and closing a vehicle door.

[0002]

[Prior art]

 As a mute operation of the conventional vehicle-mounted audio device, for example, as shown in FIG. 3, a mute or an attenuation switch 16 provided in the vehicle-mounted audio device 15 is turned on / off. ..

[0003]

[Problems to be solved by the device]

 However, in the conventional mute circuit of the on-vehicle audio system, when the passenger gets on or off while the vehicle is in operation or the driver temporarily stops from the vehicle, it is necessary to mute the audio output during the period to confirm the safety of the surroundings. However, it is difficult to operate the mute or the attenuation switch 16 instantly because the mute or the attenuation switch 16 is installed in the vehicle audio system 15. was there.

The present invention has been made in view of the above-mentioned points, and an object thereof is to solve the drawbacks of the related art and to turn on / off the mute operation simply by opening and closing the door of the vehicle. There is a mute circuit for an in-vehicle audio device.

[0005]

[Means for Solving the Problems]

 A mute circuit for an on-vehicle audio device according to the present invention is a mute circuit for an on-vehicle audio device for performing a mute or an attenuation operation on a sound output from a speaker, wherein a switch control circuit for operating the mute or the attenuation operation is provided on a vehicle. It is configured by connecting to a door switch that is turned on / off by opening and closing the door.

Further, a mute or attenuation operation function of audio output is constituted by providing a circuit for connecting the amplifier and the speaker of the vehicle-mounted audio device with a resistor and a relay for switching a short circuit of the resistor. A unit is provided and the operation of the relay is performed by turning on / off the door switch of the vehicle.

[0007]

[Action]

 According to the present invention, in the mute circuit of the vehicle-mounted audio device for mute or attenuate the sound output from the speaker, the vehicle door opens and closes the switch control circuit for operating the mute or attenuate operation. Since it is configured to be connected to a door switch that is turned on / off by, a circuit for connecting the audio output mute or the attenuation operation function to the amplifier and the speaker of the vehicle-mounted audio device is provided with a resistor, Since it is configured with a relay that switches the short circuit of the resistor, even if you do not mute the audio output of the in-vehicle audio device for safety confirmation when a vehicle passenger gets on and off, you can open it automatically by opening the vehicle door. The mute operation can be performed at any time, and the mute operation can be canceled by closing the door again.

[0008]

【Example】

 An embodiment of the mute circuit of the vehicle audio system according to the present invention will be described with reference to FIGS. 1 is a connection circuit diagram showing an embodiment of the present invention, and FIG. 2 is a connection circuit diagram showing another application example of the present invention.

In the figure, 1 is a vehicle interior lamp, 2 is a vehicle interior lamp operation changeover switch, 3 is a door switch, 4 is a mute signal input terminal, 5 is an on-vehicle audio device, 6 is a micro computer, and 7 is volume control. Electronic volume control, 8 speaker connection cord, 9 mute unit, 10 relay contacts, 11 relay coil, 12 power line, 13 power amplifier, 14 speaker.

As the configuration of the connection circuit, when the vehicle-mounted audio device is equipped with the mute signal input terminal 4, the mute signal input terminal 4 switches the lighting operation of the vehicle interior lamp 1 to switch the operation of the vehicle interior lamp. The switch 2 and the door switch 3 are connected to a connected circuit, and the mute signal input terminal 4 on one side is connected to an input port of a microcomputer 6 which controls the device in the on-vehicle audio device 5.

When the door is opened by connecting the mute signal input terminal 4 as described above and one of the door switches 3 is turned on, the mute signal input terminal 4 inputs the ground level to the micro computer 6, The microcomputer 6 controls the volume control electronic volume 7 to mute the source signal of the vehicle-mounted audio device 5 and operate to attenuate the signal to the amplifier circuit.

Further, in the case of a device in which the mute signal input terminal is not added to the on-vehicle audio device side, a resistor is connected between the power amplifier 13 and the speaker 14 as shown in FIG. The door can be opened by inserting the mute unit 9 to which the relay contact 10 is connected in parallel with the device, and connecting one terminal of the relay coil 11 that drives the relay contact 10 to the power line and the other to the door switch 3. A current flows through the relay coil 11 and the relay coil 10. When the relay contact 10 is driven so as to be turned off, a resistor is inserted between the power amplifier 13 and the speaker 14, so the output signal from the power amplifier 13 to the speaker 14 is output. Is attenuated and the mute operation can be performed.

By using the mute unit 9 in this way, it is possible to perform the mute function even in a vehicle-mounted acoustic device to which a mute signal input terminal is not added.

[0014]

[Effect of the device]

 Since the mute circuit of the vehicle-mounted audio device according to the present invention is configured as described above, it has the following effects.

Since the mute operation can be turned on and off by opening and closing the door of the vehicle, the mute operation is automatically performed when a person in the vehicle gets in or out of the vehicle, and there is an effect that safety outside the vehicle can be secured. ..

Further, by unitizing the mute circuit, it can be applied to any on-vehicle audio device.

Furthermore, there is also an effect of calling attention as a warning of a semi-closed door during operation of the on-vehicle audio device. Moreover, it has excellent features such as easy installation work because of its simple circuit configuration.

[Brief description of drawings]

FIG. 1 is a connection circuit diagram showing an embodiment of the present invention.

FIG. 2 is a connection circuit diagram showing another application example of the present invention.

FIG. 3 is a front view of a vehicle-mounted audio device to which a conventional mute switch is added.

[Explanation of symbols]

 1 vehicle interior lamp 2 vehicle interior lamp operation changeover switch 3 door switch 4 mute signal input terminal 5 vehicle audio system 6 microcomputer 7 volume control electronic volume 8 speaker connection cord 9 mute unit 10 relay contact 11 relay coil 12 power line 13 Power amplifier 14 speakers

Claims (2)

[Scope of utility model registration request] 1. In a mute circuit of a vehicle-mounted audio apparatus for performing a mute or an attenuation operation on a sound output from a speaker, a switch control circuit for operating the mute or the attenuation operation is turned on by opening and closing a vehicle door. A mute circuit for an in-vehicle audio device, which is configured by being connected to a door switch that turns on / off. 2. A mute or attenuation operation function of audio output is constituted by a resistor and a relay for switching a short circuit of the resistor in a circuit connecting an amplifier and a speaker of the vehicle-mounted audio device. The mute circuit for a vehicle-mounted audio device according to claim 1.