JPS6221053Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an audio device, and more specifically, to an audio device with a signal level adjustment function.

Conventional audio equipment uses a speaker terminal and a monitor output terminal to which earphones or headphones can be connected for playback or monitoring of a tape recorder or the like. In this case, in many monitor circuits, the speaker terminal and headphone or earphone jack output terminal are branched from the output terminal of the audio device, and the speaker terminal is connected to the earphone or headphone output terminal by inserting an earphone or headphone cord plug. However, in the case of the former, when listening with earphones or headphones during nighttime use, the signal flow to the speaker terminal must be cut off. There is a risk that the volume that you are listening to will be output from the speakers and cause a nuisance to others. If you remove it, it will switch to the speaker terminal, which has the disadvantage of producing a louder sound than the speaker and disturbing others. In these cases, the volume must be adjusted before and after using the headphones, which is troublesome.

The purpose of this invention is to eliminate the above-mentioned drawbacks, and its feature is that when the output signal from the amplifier is supplied to the headphone (or earphone) jack or speaker terminal, It has a signal level switching means that can selectively switch the connection between the signal supply terminal and the speaker terminal either directly or through a predetermined impedance, and the switching means can be switched by a headphone (or earphone) plug connected to the jack. By configuring it in conjunction with the insertion/insertion operation of the headphones, the sound output from the speakers can be suppressed to a low level when using headphones, etc., and the sound output from the speakers can be suppressed to a low level when the headphones, etc. are plugged out of the jack to disconnect them. The structure is such that the output sound can be maintained at a low level without suddenly increasing in volume. Embodiments of this invention will be described in detail below with reference to the drawings.

Both FIGS. 1 and 2 show the specific configuration of the signal level switching means of this invention, and the output terminals of the amplifier (not shown), such as the jack J and the speaker.
A signal supply terminal 1 for supplying a signal to the SP is connected to a movable contact (contact piece) _t2 of a jack J of a headphone (or earphone) via a resistor _R1 . 1st
To describe an embodiment of the present invention shown in the figure, _t1 of the jack J is a ground terminal, and _t4 is a movable contact which is interlocked with a movable contact _t2 via an insulator and is connected to a power supply terminal. ing. _T3 is always a movable contact
It is in a non-contact and non-conductive state with the movable contact _t4 , and is configured so that when a headphone (or earphone) connection plug (not shown) is inserted into the jack J, it comes into contact with the movable contact _t4 and becomes conductive. The movable contact is connected to the reset terminal R of the bistable multivibrator 2. That is, this system including the power supply +B, the movable contact t ₄ , the movable contact t ₃ , and the reset terminal R serves as a reset trigger generating means for the bistable multivibrator 2. This reset terminal R is connected to the power terminal via an operating switch (normally open contact) SW ₂ , and the set terminal S of the vibrator 2 is connected to the power terminal via an operating switch (normally open contact) SW ₁ . has been done. Furthermore, the output terminals Q of the vibrator 2 are connected to relays RL 1 and RL ₁ , respectively.
Grounded via RL ₂ .

SP is a speaker, and between the speaker SP and the signal supply terminal 1 are connected in series a switch (normally open contact) SW ₄ controlled by a resistor R ₂ and a relay RL ₂ , and a switch (normally open contact) controlled by a relay RL ₁ . Normally open contact) SW ₃
The connection is made through a parallel tangential circuit with.

Next, the operation of the configuration shown in FIG. 1 described above will be explained.

If the headphone (or earphone) connection plug is not inserted into the jack J, close the operation switch SW ₁ manually to give the set signal from the power terminal to the set terminal of the bistable multivibrator 2. The vibrator 2 is set, and an output signal of high level and low level is outputted from the output terminal Q, and the relay _RL1 is energized. The switch SW ₃ is closed by the excitation of the relay RL ₁ , and the signal from the signal supply terminal 1 is directly supplied to the speaker SP.

On the other hand, when the operating switch SW ₂ is closed manually, a reset signal is applied to the reset terminal R of the bistable multivibrator 2, which resets the vibrator 2. As a result, the output terminal Q outputs a signal from a low level to a high level. When the output signal is output and relay RL ₂ is energized, switch SW ₄
is closed (switch SW ₃ is open), and the signal from signal supply terminal 1 is attenuated by a predetermined amount by resistor R ₂ having a predetermined impedance, and then sent to speaker SP.
, and a signal suppressed to a predetermined low level is output from the speaker SP.

Now, when the headphone (or earphone) connection plug is inserted into the jack J, the movable contact (contact piece) _t2 is displaced by contact with the plug.
As the movable contact _t2, which is connected via the insulator, is also displaced, the movable contacts _t4 and _t3 come into contact and become conductive, resulting in the reset terminal R of the bistable multivibrator 2.
A reset signal is applied from the power supply terminal through contacts _t3 and _t4 , the vibrator 2 is reset, and an output signal from the low level to the high level is output from the output terminal Q, which excites the relay _RL2 and turns on the switch.
SW ₄ is closed, resulting in the operation switch described above.
Similar to the case where SW ₂ is closed, the signal flowing to the speaker SP is attenuated by a predetermined amount by the resistor R ₂ .

Therefore, in the configuration shown in Figure 1, even if the headphone (or earphone) connection plug is inserted into the jack J, the output sound continues to be output from the speaker SP, but as mentioned above, if the connection plug is inserted into the jack J
By inserting the connection plug into the jack J, the output sound level from the speaker SP is automatically suppressed to a low level. Even if the connection between movable contacts t ₃ and t ₄ is broken, the bistable multivibrator 2 maintains the reset state and is switched by relay RL ₂ .
SW ₄ remains closed and the output sound from speaker SP remains at a low level, so even if you disconnect the connection plug from jack J after using headphones etc., the speaker SP will suddenly turn off. There is no need for loud noises to come out of the SP.

If you want to obtain a normal level (not attenuated) output signal from speaker SP after removing the connection plug from jack J, close operating switch SW ₁ manually, etc., and bistable multivibrator 2 will be set again. When the switch SW ₃ is closed and the switch SW ₄ is opened, a signal is directly supplied to the speaker SP from the signal supply terminal.

Next, we will discuss another embodiment of the present invention shown in FIG. 2. Since most of the configuration is the same as that shown in FIG. 1 (including the symbols), we will not repeat the explanation. The parts that differ from the configuration shown in the diagram are always in contact and conduction with the movable contact _t4 of jack J, and are in a non-contact and non-conduction state when a connecting plug (not shown) is inserted into jack J. A movable contact t ₅ is provided, and this contact t ₅ is connected to a relay.
Ground via RL ₃ . Relay RL ₃ controls a switch SW ₅ (normally open contact) connected in series between signal supply terminal 1 and speaker SP. The other configurations are similar to those shown in FIG.

When the connection plug is not inserted into jack J, movable contacts _t4 and _t5 of jack J are in contact and conductive, so relay _RL3 receives power from the power terminal via movable contacts _t4 and _t5 . An excitation signal is applied and switch SW ₅ is held closed by relay RL ₃ . In this state, by closing the operation switch SW ₁ or SW ₂ , the bistable multivibrator 2 is set or reset, which closes the switch SW 3 or SW 4 via the relay RL ₁ or RL ₂ , and the switch SW ₃ or SW ₄ is closed. Similar to the operation of the configuration shown in FIG. 1, a signal is supplied from the signal supply terminal 1 to the speaker SP either directly or via a resistor _R2 having a predetermined impedance. In this way the switch
The output sound level of speaker SP can be selectively changed by operating SW ₁ and SW ₂ .
The difference from the embodiment shown in Fig. 1 is that when the connection plug is inserted into the jack J, the output sound from the speaker SP is automatically cut off. earphone)
When the connecting plug is inserted, the movable contact (contact piece) _t2 is displaced by contact with the plug, and the movable contact _t4 , which is connected via the insulator, is also displaced, and the movable contacts _t4 and t ₅ is in a non-contact, non-conducting state, and movable contacts t ₄ and t ₃ are in a contact, conducting state. As a result, relay RL ₃ first becomes de-energized and switch SW ₅ is opened, cutting off the output sound from speaker SP and resetting bistable multivibrator 2, thereby excitation of relay RL ₂ . This closes SW ₄ , and in this state you can listen to the sound from the jack J through the headphone (or earphone).

When the headphone etc. is finished using and the connection plug is removed from the jack J, the movable contacts t ₃ and t ₄ return to the non-contact state, t ₄ and t ₅ return to the contact state again, and the relay RL ₃ is re-energized. Switch SW ₅ is then closed. However, at this time, the bistable multivibrator 2 maintains the reset state, so switch SW ₃ remains open and switch SW ₄ remains closed. Loud sounds will not be emitted from the speaker SP.

When the connecting plug is removed from the jack J and the output sound from the speaker SP is to be returned to the normal (non-attenuated) level, the operation is the same as that described in the embodiment shown in FIG.

As described above, according to the present invention, the level of the output sound from the speaker of the audio device is configured to be related to the operation of inserting the connection plug for the headphone (or earphone) into the jack. Not only will loud sounds no longer suddenly come out from the speakers immediately after they are removed from the jack, but even if the speaker is structured so that the output sound comes out from the speakers when using headphones, etc., the connection plug will automatically respond when the connection plug is inserted into the jack. Therefore, the level of sound output from the speaker can be kept low, and the effect of using headphones or the like on the surroundings can be sufficiently taken into consideration.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are both circuit diagrams showing one embodiment of the present invention. Explanation of symbols, 1... Signal supply terminal, 2... Bistable multivibrator, J... Jack, t ₂ ~
t ₅ ……Movable contact, RL ₁ ~ RL ₃ ……Relay, SW ₁ ~
SW ₅ ...Switch, SP...Speaker, R ₁ , R ₂ ...
…resistance.

Claims (1)

[Scope of utility model registration request] In an audio device equipped with a signal supply path for supplying signals to a headphone (or earphone) jack and a speaker, respectively, the signal supply path to the speaker is a first signal supply path that directly supplies a signal to the speaker. a second signal supply path for supplying a signal to the speaker via a signal attenuation impedance, a switching means for selecting either the first or second signal path, and a headphone (or earphone) for the jack. ) control means for activating the switching means when the plug is inserted and for deactivating the switching means to maintain the previously selected state when the plug is removed; The acoustic device is characterized in that the second signal supply path is selected by operating the switching means when the plug is inserted, and the signal supply to the speaker by the second signal supply path is maintained when the plug is removed. .