JPH0247618Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a signal switching circuit, and more particularly to a signal switching circuit for a device that mixes either a plurality of signals or an externally processed signal.

BACKGROUND TECHNIQUE Conventionally, a recording medium on which accompaniment of a song, etc. is recorded is reproduced to obtain an accompaniment audio signal, and the singing audio signal obtained by a microphone is mixed with the accompaniment audio signal, and this mixed audio is generated. There is a so-called karaoke device that amplifies a signal and supplies it to a speaker to produce sound.

In such karaoke equipment, a key control unit is used to vary the pitch (key, pitch) of the accompaniment, or it adds sharpness to the singing voice by enhancing the mid-high range and rotating the phase of the singing audio signal. It is often used with the addition of an external device such as an exciter unit or a reverberation unit that gives a reverberation effect to the singing sound.

Problems that the invention aims to solve: When using a conventional karaoke device with a key control unit, the input and output terminals of the key control unit are connected to the karaoke device, and the accompaniment audio signal is extracted from the karaoke device. After changing the pitch with the key control unit, it is returned to the karaoke machine. In addition, by operating a switch on the karaoke machine, the accompaniment audio signal normally supplied to the mixing amplifier is cut off, and the accompaniment audio signal from the key control unit is supplied to the mixing amplifier, so that the accompaniment audio signal is combined with the singing audio signal. Mix. As described above, the conventional karaoke apparatus requires a complicated switching operation when connecting an external device, and has a problem in that it is not easy to use.

Therefore, an object of the present invention is to provide a signal switching circuit that solves the above problems.

Means and Effects for Solving Problems The present invention outputs a part of a plurality of signals to the outside for processing by an external device, and also outputs one of the plurality of signals and a signal processed externally. A signal switching circuit for a device that mixes signals in a mixing circuit, which includes a detection means provided at an output terminal of each of a plurality of signals and an input terminal from an external device to detect a terminal connection with an external device, a selection means for selecting one of the plurality of signals and the signal entering the input terminal and supplying the selected signal to the mixing circuit; and controlling the selection means in accordance with the detection signal of the detection means. Each of the embodiments thereof will be described with reference to FIG. 1 and subsequent figures.

Embodiment FIG. 1 shows a circuit diagram of a first embodiment of the circuit of the present invention. In the figure, an audio signal of the right channel of a song, for example, obtained by a microphone is input to terminal 1 via a microphone amplifier, a tone control circuit, etc. (not shown). Further, an audio signal of the right channel of accompaniment, for example, reproduced from a recording medium is input to the terminal 2 via a tone control circuit or the like.

Terminal 1 is terminal 3a of switch 3 which is selection means.
The terminal 2 is connected to the terminal 5a of the switch ₅ , which is a selection means, and the buffer amplifier 4 is connected to the buffer amplifier 4 via the resistor R1.
It is connected to the buffer amplifier 6 via _R2 .
The output terminal of the buffer amplifier 4 is connected to a terminal 7a of a pin jack 7 with a switch for microphone pre-output. The switch portion 7b of the pin jack 7, which is the detection means, is normally open, one contact is grounded, and the other contact is connected to one end of the relay coil 8. The output terminal of the buffer amplifier 6 is connected to a terminal 9a of a pin jack 9 with a switch for playback pre-output, and the switch part 9b of the pin jack 9, which is the detection means, is normally open, one contact is grounded, and the other contact is grounded. is connected to one end of the relay coil 10. Further, the terminal 3b of the switch 3 and the terminal 5b of the switch 5 are commonly connected to the terminal 11a of the pin jack with switch 11 for line input, and the pin jack 1 which is the detection means
Switch part 7b of No. 1 is normally open and one contact is connected to terminal No. 1.
Power is supplied from 6, and the other contact is connected to the other ends of relay coils 8 and 10, which are control means. Incidentally, surge absorbing diodes D ₁ and D ₂ are provided in parallel with the relay coils 8 and 10, respectively. Switches 3 and 5 each have a relay coil 8,
10, each movable contact piece is normally connected to terminal 3a, 5a, and when the relay coils 8, 10 are energized, the movable contact piece is connected to terminal 3a, 5a.
b and 5b, respectively. The movable contacts of the switches 3 and 5 are connected to a mixing amplifier 12, which is a mixing circuit, via resistors R ₃ and R ₄ , respectively, and the output terminals of the mixing amplifier 12 are for the main amplifier (not shown) and mix output. The terminal 13a of the pin jack 13 is connected to the terminal 13a of the pin jack 13. Of course, the left channel song and accompaniment audio signals are also supplied to the same circuit as shown in the first diagram, and their explanation will be omitted.

If the pitch of the accompaniment is to be varied, a plug of the key control unit 20 is inserted into each of the pin jacks 9 and 11 in order to add a key control unit 20 as shown in FIG. 2A. Therefore, switch portions 9b and 11b of pin jacks 9 and 11 are closed, current flows through relay coil 10, and the movable contact piece of switch 5 is connected to terminal 5b. In addition, the movable contact piece of the switch 3 is the terminal 3
Connected to a. Therefore, the mixing amplifier 12
is supplied with only the singing audio signal from the terminal 1 and the accompaniment audio signal whose pitch is varied by the key controller 20, and these are mixed and supplied to the main amplifier.

Further, when adding sharpness to the singing voice, a plug of the exciter unit 21 is inserted into each of the pin jacks 7 and 11 in order to add an exciter unit 21 as shown in FIG. 2B. As a result, switch portions 7b and 11b are closed, and the movable contact piece of switch 3 is connected to terminal 3b. Therefore, only the accompaniment audio signal from the terminal 2 and the singing audio signal from the exciter unit 21 are supplied to the mixing amplifier 12 and mixed.

In addition, in order to further mix the external audio signals coming into the terminal 22, an external mixer 23 is added as shown in FIG. 2C, so the pin jack 7,
Insert the mixer 23 plug into ports 9 and 11. As a result, the switch parts 7b, 9b, 11b are closed, and the movable contact pieces of the switches 3, 5 are connected to the terminals 3b, 11b, respectively.
5b, and only the audio signals of the song, accompaniment, and terminal 22 mixed by the mixer 23 are supplied to the mixing amplifier 12.

Further, when recording an accompaniment, for example, a cassette deck 24 is added as shown in FIG. 2D, and the plug of the cassette deck 24 is inserted into the pin jack 9. In this case, since the switch portion 11b is open, no current flows through the relay coils 8 and 10, and the movable contacts of the switches 3 and 5 are connected to the terminals 3a and 10, respectively.
5a, and the audio signals of terminals 1 and 2 are supplied to the mixing amplifier 12 and mixed in the same manner as usual. Similarly, a song (or song and accompaniment) can be recorded by inserting the plug of the cassette deck 24 into the pin jack 7 or 13.

In this way, the connections of the switches 3 and 5 are automatically changed according to the state of insertion of the plug of the external device into the pin jacks 7, 9, and 11, and the user does not need to operate the switches. This improves usability.

FIG. 3 shows a circuit diagram of a second embodiment of the circuit of the present invention. In the figure, the same parts as in FIG. 1 are designated by the same reference numerals, and their explanations will be omitted. In FIG. 3, 14 is a slide switch, a terminal 14a is connected to a terminal 16 to which power is supplied, a terminal 14b is connected to the other end of each of the relay coils 8 and 10, and a terminal 14c
is open. The slide switch 14 has an on state in which the slider 14d connects the terminals 14a and 14b, and an off state in which the slider 14d connects the terminals 14b and 14c. In the off state, the circuit shown in FIG. 3 is the circuit shown in FIG. works the same way.

Further, by turning on the slide switch 14, the song and the accompaniment can be amplified by independent power amplifiers. In this case, as shown in FIG. 2E, in order to add a power amplifier 25 externally, the plug of the power amplifier 25 is inserted into the pin jack 7. At this time, since the slide switch 14 is in the on state, current flows through the relay coil 8 and the movable contact piece of the switch 3 is connected to the terminal 3b. This allows terminal 1
The audio signal of the song is amplified by an external power amplifier 25 and then supplied to the speaker 26, and only the accompaniment audio signal of the terminal 2 is supplied to the mixing amplifier 12, after which it is amplified by the power amplifier 15 inside or outside the karaoke apparatus. The signal is amplified and supplied to the speaker 27. Similarly, by inserting the plug of the power amplifier 25 into the pin jack 9, the accompaniment audio signal at the terminal 2 can be amplified by the external power amplifier 25.

Although the circuit of the present invention is particularly suitable for karaoke equipment, it may be applied to any other equipment.
It is not limited to the above embodiments.

Effects of the Invention As described above, the signal switching circuit according to the present invention outputs a part of a plurality of signals to the outside for processing by an external device, and also outputs a part of a plurality of signals and a signal processed externally. A signal switching circuit for a device that mixes a plurality of signals in a mixing circuit, the detection means being provided at an output terminal of each of a plurality of signals and an input terminal from an external device to detect a terminal connection with an external device; a selection means provided for each of the plurality of signals and a signal entering the input terminal and supplying the selected signal to the mixing circuit; Since the selection means automatically switches the signal supplied to the mixing circuit according to the connection state of the external device, the user does not need to operate a switch, improving the usability of the device. It has.

[Brief explanation of drawings]

1 and 3 are circuit diagrams of each embodiment of the circuit of the present invention, and FIG. 2 is a block system diagram for explaining the usage state of the circuit of the present invention. 1, 2, 16... terminal, 3, 5, 14... switch, 4, 6... buffer amplifier, 7, 9, 1
1, 13...pin jack, 7b, 9b, 11b
...Switch part, 8, 10...Relay coil, 1
2...Mixing amplifier.

Claims (1)

[Scope of utility model registration request] A signal switching circuit for a device that outputs a part of a plurality of signals to the outside for processing by an external device, and mixes any of the plurality of signals and the externally processed signal by a mixing circuit. , detection means provided for each of the output terminals of the plurality of signals and each of the input terminals from the external device to detect a terminal connection with the external device; selection means for selecting one of the signals entering the input terminal and supplying the selected signal to the mixing circuit; and control means for controlling the selection means in accordance with the detection signal of the detection means. A signal switching circuit consisting of: