JPS60237798A - Headphone speaker output changeover system - Google Patents

Abstract

PURPOSE:To use a headphone and a speaker at the same time by setting selectively a mode applying an audio signal from a different signal source respectively to the headphone and the speaker. CONSTITUTION:A switch 4' is closed in interlocking with the loading of the headphone to a headphone jack 4, a constant voltage source circuit 8 is activated and an amplifier 7 starts the operation. In this case, in closing a switch 12 to the position of a changeover circuit 6, a transistor 6' is turned on and an audio signal at a deck signal input terminal 14 is fed to the amplifier 7. Moreover, the switch 11 is kept open through the changeover of the switch 12 and a control signal at a deck/radio changeover control input terminal 9 is not fed to a priority decidion circuit and the radio receiver is not turned off. Thus, the audio signal of the receiver is fed to the amplifier via the terminals 15, 16 and fed to the speaker via an audio signal input terminal 1 after amplification.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to an in-vehicle sound system equipped with a radio receiver, a tape deck, etc., and particularly to a headphone/speaker that allows switching between the use of headphones and speakers. Regarding the output switching system.

[Background of the invention]

Conventional in-vehicle sound systems such as car stereos do not allow the use of headphones and speakers at the same time, so for example, you can listen to music from a tape deck through headphones and listen to radio broadcasts through the speakers at the same time. I couldn't.

FIG. 81 is a circuit diagram showing an example of a conventional headphone/speaker output switching system for switching the supply of audio signals to headphones and speakers, and 1 is an audio signal input terminal.

2 is an amplifier terminal, 3 is a speaker connection terminal, 4 is a headphone jack with a switch, 4' is a switch, 5 is a relay, and 5' is a transistor for driving the relay.

In the figure, an audio signal from an audio signal source such as a radio receiver or a tape deck is amplified by an audio amplifier (not shown) and supplied to an audio signal input terminal. A predetermined power supply is connected to the amplifier 10B terminal 2, and a speaker (not shown) is connected to the speaker connection terminal 3.

In Figure 1, headphone jack 4 is connected to headphones (
(not shown), the switch 4' is open, the transistor 5' is turned off, and the relay 5 is closed to the speaker connection terminal 3 side. Therefore, the audio signal will be supplied to the speaker.

On the other hand, when headphones are attached to the headphone jack 4, the switch 4' is closed and the transistor is turned on.

Therefore, the relay 5 closes to the headphone jack 4 side,
Audio signals are provided to headphones.

In this way, conventionally, it was not possible to listen to music through speakers when using headphones.

However, with the recent diversification of the use of in-vehicle audio systems, there is a desire for an in-vehicle audio system that has a function that allows the use of headphones and speakers at the same time.

[Purpose of the invention]

An object of the present invention was made in view of the above-mentioned circumstances, and it is an object of the present invention to provide a headphone/speaker output switching system for an in-vehicle audio system that allows use of headphones and speakers at the same time.

[Summary of the invention]

To achieve this objective, the present invention provides a method for supplying headphones with an audio signal from a tape deck when the headphones and speakers are used simultaneously, and supplying audio signals from other audio signal sources to the speakers, and providing audio signals for the headphones only when the headphones and speakers are used simultaneously. When used, the headphones can be supplied with an audio signal from either audio signal source.
The present invention is characterized in that an audio signal from an audio signal source is selectively switched to a speaker and a headphone, so that the headphone and the speaker can be used at the same time.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

Ru.

FIG. 2 is a circuit diagram showing an embodiment of the headphone/speaker output switching system according to the present invention, in which 6 is a switching circuit, 6' is an NPN transistor, 7 is a headphone amplifier, and 8 is a constant voltage source circuit. , B' 5p7v type power transistor, 9 is a deck/radio switching control signal input terminal, 10 is a deck/radio switching control signal output terminal, 11.
12.1F+ is a switch, 14 is a deck signal input terminal,
15 is an audio amplifier connection terminal, 16 is a radio receiver signal input terminal, and 17 is a volume, and parts corresponding to those in FIG. 1 are given the same reference numerals.

The deck signal input terminal 14 is supplied with an audio signal from the tape deck, and the radio receiver signal input terminal 16 is supplied with an audio signal from the tape deck.
is supplied with an audio signal from a radio receiver. The audio amplifier connection terminal 15 is
It is connected to an audio amplifier input (not shown), and an audio signal output from the audio amplifier is supplied to the audio signal input terminal 1.

A priority JI ranking determination circuit (not shown) is connected to the deck/radio switching control signal output terminal 10 for determining which operation of the tape deck or the radio receiving device should be prioritized. Control signal input terminal 9
When the control signal supplied to the switch 11 is supplied by closing the switch 11, the priority determining circuit is activated. The switch 11 opens when the switch 12 closes to the switching circuit 6 side, and the switch 12 opens when the switch 12 closes to the switching circuit 6 side.
It is linked to the switch 12 so that it closes when it is closed to the side.

When the switch 13 is switched, the amplification curtain of the headphone amplifier 7 is changed, and by appropriately adjusting the volume 17, the amplitude of the audio signal supplied to the headphone amplifier 7 can be changed.

Next, the operation of this embodiment will be explained.

In Figure 2, headphone jack 4 is connected to headphones (
(not shown) is not installed, switch 4'
becomes open. This method, power transistor 8
' is not turned on, the constant voltage source circuit 8 does not operate, and the headphone amplifier 7 to which power is not supplied to the constant voltage source circuit 8 also does not operate. At this time, transistor 6' is off,
The radio receiver signal from the input terminal 16 is connected to the audio amplifier connection terminal 15.
is output to.

Furthermore, since the transistor 5' is turned off, the relay 5 remains closed, and the audio signal being supplied to the audio signal input terminal 1 is supplied to the speaker.

Therefore, when the headphones are not in use, the tape deck and radio receiver can be selectively listened to through the speakers.

Next, when the headphone amplifier is connected to the headphone jack 4, the switch 4' is closed, and the constant voltage source circuit 8 starts operating, so that the headphone amplifier 7 starts operating.

In this case, when the switch 12 is closed to the switching circuit 6 side, the transistor 6' is turned on, so the audio signal from the radio receiver signal input terminal 16 is not supplied to the head amplifier 7, and the audio signal from the deck signal input terminal 14 is not supplied to the head amplifier 7. Only the audio signal is supplied to the headphone amplifier 7.

However, since the switch 12 is changed as described above, the switch 11 is in the open state, and the control signal of the deck/radio switching control signal input terminal 9 is not supplied to the priority order determining circuit, so that radio reception is not possible. The machine is not turned off.

The audio signal from the radio receiver is sent to the radio receiver signal input terminal 16 and the audio amplifier connection terminal 1.
5 to an audio amplifier (not shown);
After being amplified, the signal is supplied to the speaker via the audio signal input terminal 1.

In this way, you can listen to the tape deck through headphones and at the same time listen to the radio receiver through the speakers.

On the other hand, when the switch 12 is closed to the relay 5 side while the headphones are still being worn, the transistor 5' is turned on and the relay 5 is opened. Therefore, no audio signal is supplied to the speaker.

Further, since the switch 12 is switched as described above, the transistor 6' is not turned off, and the audio signal from the radio receiver signal input terminal 16 or the audio signal from the deck signal input terminal 14 is transmitted to the headphones. Now supplied to the amplifier. In addition, since the switch 11 is closed in conjunction with the switch 12, the priority determination circuit (not shown) is operated by the control signal from the deck/radio switching control signal input terminal 9 to the tape deck and the radio. The audio signal from the one of the receivers that is turned on is supplied to the headphone amplifier 7.

Therefore, when the speakers are not in use, the headphones allow selective listening to either the radio receiver or the tape deck.

As explained above, it is now possible to use headphones and speakers at the same time.

〔Effect of the invention〕

As explained above, according to the present invention, when listening to a tape deck through headphones, other audio signal sources can be simultaneously listened to through the speakers, and when the speakers are not used, the desired audio signal source can be listened to through the headphones. Since the switching is performed so that the user can listen to the sound, it is possible to diversify the use and provide a Heradbon speaker output switching circuit with excellent functions.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an example of a conventional headphone e-speaker output switching system, and FIG. 2 is a circuit diagram showing an embodiment of the headphone/speaker output switching system according to the present invention. 1...Audio signal input terminal 2...Amplifier 10B terminal 3...Speaker connection terminal 4
... Headphone jack with switch 5 ... Relay 6 ... Switching circuit 7 ... Headphone amplifier 8 ... Constant voltage source circuit 9.
... Deck/radio switching control signal input terminal 10... Deck/radio switching control signal output terminal 11, 12...
Switch 14...Deck signal input terminal 15...Audio amplifier connection terminal 16...Radio receiver signal input terminal Figure 1

Claims (1)

[Claims] In a vehicle-mounted sound system that includes a plurality of audio signal sources and selectively supplies audio signals from the audio signal sources to speakers and headphones, when the headphones are turned off, the audio signal sources are supplied to the speakers. a first mode in which the headphone is selectively supplied with an audio signal from the audio signal source and the speaker is turned off when the headphone is turned on; A headphone/speaker output switching system characterized in that a second mode for supplying audio signals from different audio signal sources to the horn and the speaker can be selectively set.