JPH046320Y2 - - Google Patents

Description

[Detailed explanation of the invention] (a) Industrial application field This invention is suitable for setting the volume balance of rear speakers and front speakers connected to the output terminal of a power amplifier that constitutes an in-vehicle audio equipment. This relates to a fader circuit.

(B) Prior Art As a conventional fader circuit, there is one constructed as shown in the block wiring diagram of FIG. 4, for example. (Utility Model Application No. 61-156400) In the figure, 1 is a signal source consisting of an audio signal, and the audio signal output from this signal source 1 is sent to the first and second output terminals 20, 24.
and the first and second output terminals 2
This is a pre-fader 3 that adjusts the volume level of the front speaker 17 and other rear speakers 19 connected to the speakers 0 and 24.

Therefore, the audio signal is transmitted from the signal source 1
A power amplifier 5 is selectively connected to the prefader 3 and amplifies the input audio signal, and the audio signal output from the power amplifier 5 is connected to the first and third output terminals 2.
0, 21 and connected to the first and third output terminals 20, 21, the front and rear speakers 17,
Power fader 4 to adjust the volume balance of 18
, the prefader 3 and the second output terminal 2
7 and a switch 7.
It has C.

This switch 7C selectively connects the A signal 22 and the first and third output terminals 20 and 21 via the power amplifier 5 and the power fader 4, or connects the B signal 23 and the first output terminal 20 via the power amplifier 5 and the power fader 4. The signal source 1 and the second output terminal 27 are connected via a prefader 3 and a power fader 4, and a prefader 3 and a preamplifier 6 between the signal source 1 and the second output terminal 27, respectively.

(c) Problems to be solved by the invention However, in the conventional device described above, many switches 7D, 7E, and 7F are connected to the output circuits of the power amplifier 5 and the preamplifier 6, and the switches 7D, 7E, and Among the switches 7D and 7E among the switches 7F, a large current flows, so large switches are required, which causes an increase in the cost of materials.

In addition, when the audio signal from signal source 1 selects contact A at switch switch 7C, power amplifier 5
The disadvantage is that the A signal 22 input to the prefader 3 cannot be supplied to the prefader 3.

This invention was made in view of the above points, and its purpose is to eliminate the drawbacks of the conventional example by forming the pre-fader and power fader from interlocking variable resistors and interlocking switches. The purpose of the present invention is to provide a fader circuit.

(d) Means for solving the problem The fader circuit according to this invention connects a signal source consisting of an audio signal, the audio signal from this signal source to the input of a power amplifier and a preamplifier, and balances the input of each audio signal. a prefader circuit that sets the prefader circuit, a preamplifier circuit that inputs the audio signal from the prefader circuit and supplies its output to the preout terminal, a power amplifier circuit that amplifies the audio signal input from the prefader circuit, and this power amplifier. In the fader circuit consisting of a power fader circuit that distributes the output from the front speaker and the rear speaker to the front speakers and sets the volume balance for each, the audio signal from the volume setting volume connected to the above signal source is divided into two, and one of the The attenuator circuit connected to the audio signal and the audio signal from the attenuator circuit further divided into two, the audio signal passing through one terminal from the connected prefader terminal and the audio signal from the attenuator circuit, respectively, can be selected. and a second switch circuit capable of selecting an audio signal obtained by connecting an external device to the pre-out output terminal and the other audio signal from the pre-fader terminal using interlocking switches. , a prefader circuit, and
The power fader circuit is also formed of interlocking variable resistors, so that it is possible to select whether to operate the prefader circuit and the power fader circuit simultaneously or only the power fader circuit.

(e) Effect When contact A is selected by the first and second interlocking switches, the audio signal input to the power amplifier is supplied through one of the volume and prefader terminals.

Further, the other terminal of the prefader is connected to a preamplifier.

Furthermore, the front speaker or the rear speaker was connected to the output circuit of the power amplifier, and the rear speaker or the front speaker was connected to the output of the external power amplifier connected to the pre-out terminal.

Therefore, when the rotating shafts of the interlocking pre-fader and power fader are turned in one direction, the volume of the front speaker or rear speaker connected to the speaker output terminal from the power amplifier does not change, and the volume of the rear speaker or front speaker is changed. The volume gradually decreases. Also, if you turn the rotation axis in the other direction, the result will be the opposite of the above.

That is, the volume balance between the front speakers and the rear speakers can be set using the pre-fader.

Next, when contact B is selected by the first and second switches, the audio signal input to the preamplifier is supplied via the volume and attenuator.

Therefore, the audio signal passes through external equipment such as a graphic equalizer, network, etc. connected to the pre-out terminal, and is input to the power amplifier via the power amplifier input terminal and contact B of the second switch. In this case, since contact B of the second switch is selected, the audio signal is not supplied to the prefader, so it is impossible to set the volume balance between the front speakers and the rear speakers using the prefader.

However, as mentioned above, the audio signal is supplied from the preamplifier to the power amplifier via the external device, so the volume level of the front speakers and rear speakers can be set by the power fader connected to the output circuit of the power amplifier. Contact A
The result will be the same as if you selected .

(F) Embodiment An embodiment of the fader circuit according to this invention will be described with reference to FIGS. 1 to 3.

FIG. 1 is a block wiring diagram showing the entire system, and FIGS. 2 and 3 are wiring diagrams of main parts.

First, to explain the overall configuration, 1 is a signal source consisting of an audio signal, and this signal source 1
is connected to Volume 2 to set the volume level.

The audio signal passing through this volume 2 is 2
One audio signal was supplied to the attenuator 10, and the other was further divided into two and supplied to both terminals 26A and 26B of the prefader 3A.

The audio signal is supplied to contact B via an attenuator 10. Moreover, a first switch 7A is provided to select the audio signal supplied to the contact A via one terminal 26A of the prefader 3A.

The audio signal from this first switch 7A was supplied to the input of the preamplifier 6. Therefore, the output signal of the preamplifier 6 is supplied to the power amplifier input terminal 9 via an external device 16 such as a graphic equalizer or a network connected to the preout terminal 8.

The audio signal from this power amplifier input terminal 9 is supplied to contact B of the second switch 7B.

Further, the other terminal 26B of the prefader 3A is connected to the second switch 7B in order to select the audio signal connected to the contact A of the second switch 7B and the audio signal supplied to the contact B.
has been established. In addition, the first and second switches 7A, 7B
is formed by coaxial interlocking.

The audio signal selected by the second switch 7B is supplied to the input of a power amplifier 5 for power amplification. The output circuit of this power amplifier 5 has two paths, and the power fader 3B is connected to both ends of the output circuit.

This power fader 3B is formed from four terminals, and these terminals 24A and 24B each have one output terminal (plus, minus) for front speakers.
Connect to terminals 3A and 13B, and then connect terminals 25A and 25.
B was connected to rear speaker output terminals (plus, minus) 14A and 14B, respectively. The pre-fader 3A and power fader 3B described above are coaxially interlocked rotary variable resistors.

Next, these operations will be explained.

First, the first and second switches 7 are interlocked.
When contact A is selected for each of A and 7B, the power amplifier 5 is supplied with an audio signal via the volume 2, the prefader 3A, and the contact A of the switch 7B.

On the other hand, the preamplifier 6 is supplied with an audio signal via the volume 2, the prefader 3A, and the contact A of the switch 7A.

For example, pre-fader 3A and power fader 3
When the rotation axis of switch B is fully turned to one side or the other, the audio signal is no longer supplied to the power amplifier 5 through contact A of switch 7B.
It becomes impossible to set the volume balance between the front speakers and rear speakers.

To do this, as shown in FIG.
4B, and a rear speaker 18 is also connected to the pre-out terminal 8 via an external power amplifier 15.

As a result of connecting the above external power amplifier 15,
When the rotating shafts of the pre-fader 3A and the power fader 3B, which are coaxially interlocked, are turned in one direction, the volume of the front speaker 17 or rear speaker 18 decreases without changing the volume of the front speaker 17 or rear speaker 18. If you turn it off, there will be no output.

Furthermore, when the rotating shaft is turned in the other direction, the outputs from the respective speakers 17 and 18 become opposite to the above. That is, it is possible to arbitrarily set the volume balance for the front speaker 17 and the rear speaker 18.

When contact B is selected by the first and second switches 7A and 7B, the audio signal input to the preamplifier 6 is supplied from the volume 2 via the attenuator 10. Therefore, the audio signal is inputted from the power amplifier input terminal 9 via the external device connected to the pre-out terminal 8 to the power amplifier 5 via the contact B of the second switch 7B.

However, since the first and second switches 7A and 7B each select contact B, the audio signal is not supplied to the prefader 3A, but the output of the power amplifier 5 is supplied to the power fader 3B.
is supplied to.

Therefore, output terminals 13A, 13B and 14
A and 14B each have front speakers and
When the rear speakers are connected, the volume balance setting of the front speakers and rear speakers can be set by rotating the rotating shafts of the pre-fader 3A and power fader 3B, which are coaxially interlocked, in the same way as when contact A is selected. It becomes possible.

Briefly stated again, the audio signal when contact A is selected is divided into two parts from the prefader 3A, one being supplied to the power amplifier 5 and the power fader 3B, and the other being supplied from the preamplifier 6 to the external power amplifier 15.

Next, when contact B is selected, the audio signal passes from the attenuator 10 to the preamplifier 6.
By supplying the signal to the power fader 3B via the external device 16 and the power amplifier 5, the volume balance can be set arbitrarily.

Note that FIG. 2 shows a case where contact A is selected as described above and the pre-out terminal 8, which is the output circuit of the preamplifier 6, and the input of the external power amplifier 15 are connected. A two-power amplifier 4 in which a rear speaker 18 is connected to the output of this external power amplifier 15, and a front speaker 17 is further connected between the front speaker output terminal 13A (plus side) and the rear speaker output terminal 14B (minus side). It is a speaker system.

In Fig. 3, contact B is selected, and the pre-out terminal 8 and the power amplifier input terminal 9 are connected directly or via the external device 16, and the front Speaker 17 and rear speaker 18
It is a 1 power amplifier and 4 speaker system that is connected to the following.

As another application example, the first and second switches 7
A, 7B are mechanically interlocked, and a relay that is an electrical switch, an analog switch, or
A similar effect can be achieved with a combination of mechanical and electrical switches.

(g) Effects of the invention According to the fader circuit according to this invention, since the pre-fader and the power fader are formed by interlocking variable resistors, the operability associated with setting the volume balance of the front speaker and the rear speaker can be improved.

In addition, since the switch was installed in a small signal circuit, a small switch was sufficient, and in addition, the number of switches was reduced and the switch was formed using interlocking switches.
It has become possible to reduce material costs.

Furthermore, it is possible to connect the output of the preamplifier to external equipment such as an external power amplifier, graphic equalizer, network, etc., and in this case as well, it has the effect of a power fader.

Moreover, it has excellent features such as a simple circuit configuration and easy implementation.

[Brief explanation of the drawing]

1 to 3 show an embodiment of the fader circuit according to this invention, FIG. 1 is a block wiring diagram showing the whole, FIGS. 2 and 3 are wiring diagrams of main parts, and FIG. The figure is a block wiring diagram showing a conventional fader circuit. 1...Signal source, 2...Volume, 3,3A...
...Prefeeder, 3B, 4...Power feeder,
5...Power amplifier, 6...Preamplifier, 7A~
7F...Switch, 8...Pre-out terminal, 9...
...Power amplifier input terminal, 10...Attenuator, 13A...Output terminal for front speaker (plus), 13B...Output terminal for front speaker (minus), 14A...Output terminal for rear speaker (plus), 14B... Rear speaker output terminal (minus), 15... External power amplifier, 16...
...External device, 17...Front speaker, 24
A, 24B, 25A, 25B, 26A, 26B...
... terminal, 18 ... rear speaker, 19 ... other rear speaker, 20, 21, 27 ... output terminal, 2
2...A signal, 23...B signal.

Claims (1)

[Claim for Utility Model Registration] A signal source consisting of an audio signal, a prefader circuit that connects the audio signal from this signal source to the inputs of a power amplifier and a preamplifier and sets the input balance of each audio signal, and this prefader circuit. a preamplifier circuit that inputs an audio signal from the prefader circuit and supplies its output to a preout terminal; a power amplifier circuit that amplifies the audio signal input from the prefader circuit; and a power amplifier circuit that amplifies the audio signal input from the prefader circuit; an attenuator circuit which divides the audio signal from the volume setting volume connected to the signal source into two, and to which one of the audio signals is supplied; A first switch circuit that further divides the other audio signal into two and makes it possible to select between the audio signal that passes through one terminal from the connected prefader terminal and the audio signal from the attenuator circuit, and the pre-out output terminal. A second switch circuit that can select the audio signal obtained by connecting an external device to the prefader terminal and the other audio signal from the prefader terminal is formed by an interlocking switch, and the prefader circuit and power fader circuit are also interlocked. 1. A fader circuit characterized in that the fader circuit is formed of type variable resistors so that it is possible to select whether to operate the prefader circuit and the power fader circuit simultaneously or to operate only the power fader circuit.