KR910003568Y1 - Flurte tone color generating circuit of electronic key-board - Google Patents

Abstract

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Description

Flute sound generator circuit of electronic keyboard

1 is a circuit diagram according to the present invention.

2 is an operational waveform diagram of FIG. 1 according to the present invention.

* Explanation of symbols for main parts of the drawings

10: microcomputer 20: sound source signal generator

30: square wave signal generator 40: sinusoidal signal generator

50: mixing amplifier 68: main amplifier

70: speaker

The present invention relates to a flute tone generating circuit of an electronic keyboard, and more particularly, to a flute tone generating circuit of an electronic keyboard which reproduces the sound of a flute musical instrument using a filter means.

In general, musical instruments vary in tone according to the number of musical instruments. Conventional flute tone circuits have not been able to produce accurate flute tones because the number of instruments is low, and there has been a problem with complicated operational amplifiers.

Therefore, the purpose of the present invention is to increase the number of heat of the instrument to create a square wave similar to the flute sound, and to input the square wave to a simple filter means to generate a flute sound, accurate flute sound can be obtained and the circuit configuration can be simplified. The present invention provides a flute tone generating circuit of an electronic keyboard.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a circuit diagram according to the present invention, where 10 is a microcomputer that outputs data corresponding to a user pressing any key of the key, and 20 is a system divided by a predetermined ratio according to the data of the microcomputer 10. A sound source signal generator for generating one sound source signal, a second sound source signal, and a third sound source signal and outputting the same through the output terminals A, B, and C, respectively, and 30 denotes the first node 1 and the inverting terminal (-). An operational amplifier 322 connected to the power supply line 8 and a non-inverting terminal +, a second node 2 connecting an output terminal of the operational amplifier 322, and the sound source signal generator 20 The capacitor 301 connected in series between the output terminal A of the first terminal 1 and the first node 1, the resistor 311 connected in series with the capacitor 301, and the first node 1 and one end A capacitor 302 for connecting and connecting the second node 2 and the other side end thereof, and a low capacitor connected in parallel with the capacitor 302. 312, a capacitor 303 connected in series between the second node 2 and a ninth node 9, and a resistor 313 and a third node 3 connected in series with the capacitor 303. An operational amplifier 323 for connecting an inverting terminal (-) and a power supply line 8 and a non-inverting terminal (+), and a fourth node 4 for connecting an output terminal of the operational amplifier 323; A capacitor 304 connected in series between the output terminal B of the sound source signal generation 20 and the third node 3, a resistor 315 connected in series with the capacitor 304, and the third node ( 3) and a capacitor 305 for connecting one side end and the other end of the fourth node 4, a resistor 314 connected in parallel with the capacitor 305, and the fourth node 4, A capacitor 306 connected in series between the ninth node 9, a resistor 316 connected in series with the capacitor 306, a fifth node 5 and an inverting input terminal (-), and a power supply line ( 8) and non-inverting terminal (+) The sixth node 6 which connects the operational amplifier 324 to be connected, the output terminal of the operational amplifier 324, and the one end of the fifth node 5 to be connected to the sixth node 6 is different from the sixth node 6. A capacitor 308 connecting the side ends, a resistor 318 connected in parallel to the capacitor 308, and an output terminal C of the sound source signal generator 20 and a series node connected in series between the fifth node 5; A resistor 317 connected in series with the capacitor 307 and the capacitor 307, and a capacitor 309 and the capacitor 309 connected in series between the sixth node 6 and the ninth node 9. A resistor 319 connected in series, a seventh node 7 connected to the power supply line 8, a capacitor 310 connected in series between the seventh node 7 and ground, and the seventh A resistor 320 connected in series between the node 7 and the ground, and a resistor 321 connected in series between the seventh node 7 and the power supply VCC. One A square wave signal generator 30 which amplifies a sound source signal, a second sound source signal, and a third sound source signal and synthesizes the same to generate a square wave signal similar to a flute sound, and 40 denotes one side of the ninth node 9. A resistor 401 for connecting the ends, a resistor 402 for connecting the other end and one end of the resistor 401, a resistor 403 for connecting the other end and one end of the resistor 402, A resistor 404 connecting the other end and one end of the resistor 403, and a transistor 412 connecting the other end and the collector end of the resistor 404 and connecting the tenth node 11 and the emitter end. And a capacitor 408 for connecting one end between the resistors 401 and 402, a capacitor 409 for connecting one end between the resistors 402 and 403, and the resistor 403. ) Is connected between the capacitor 410 and one end connected between the resistor 404 and the collector of the transistor 412. A capacitor 411, an open / close switch 413 connected in series between the base end of the transistor 412 and a power supply VCC, a resistor 406 connected in series to the open / close switch 413, and the tenth node. And a resistor 407 connected in series between the eleventh and the ground, and a resistor 405 for connecting the tenth node 11 and one end thereof to the square wave signal of the square wave signal generator 30. Sine wave signal generation unit for generating a sine wave signal, such as the waveform of the flute tone by multi-stage filtering, and outputs when the flute sound is selected by the user, 50 is a sine wave signal of the sine wave signal generator 40 and a predetermined rhythm A mixing amplifier for mixing and amplifying mixing, 60 is a main amplifier for amplifying the output of the mixing amplifier 50, 70 is a speaker for outputting the amplified signal from the main amplifier 60 as an audible sound.

2 is a waveform diagram of FIG. 1 according to the present invention, (a) is a first sound source signal waveform of the sound source signal generator 20, (b) is a second sound source signal waveform of the sound source signal generator 20, ( c) is a third sound source signal waveform of the sound source signal generator 20, (d) is a waveform signal waveform of the square wave signal generator 30, (e) is a sine wave signal waveform of the sine wave signal generator 40 to be.

Hereinafter, the present invention will be described in detail with reference to FIGS. 1 and 2.

First, in the following description, a ratio of resistance 313 = 1.2 x resistance 316 = 1.8 x resistance 319 is configured.

When the user presses any key (not shown), the microcomputer 10 inputs data corresponding thereto to the sound source signal generator 20, and the sound source signal generator 20 divides the second 2A into a predetermined ratio. A second sound source signal of the same first sound source signal 2b degree and a third sound source signal of the same 2c degree are generated. The first sound source signal passing through the output terminal A of the sound source signal generator 20 is input to the inverting terminal (−) of the operational amplifier 322 through the capacitor 301 and the resistor 311 and at the same time the capacitor 302. ) And one side of the resistor 312.

In addition, a reference voltage Vcc of a predetermined level is input to the non-inverting terminal (+) of the operational amplifier 322 by an integrating filter composed of a resistor 321 and a capacitor 310. Since the operational amplifier 322, the capacitor 302, and the resistor 312 have a structure of a conventional amplifier, the operational amplifier 323 may be amplified by the capacitor 304 and the resistor 315 after amplifying the first sound source signal. Input to the inverting terminal (-) and at the same time through the capacitor 305 and the resistor 313 to the ninth node (9).

The second sound source signal passing through the output terminal B of the sound source signal generator 20 is input to the inverting terminal (−) of the operational amplifier 323 through the capacitor 304 and the resistor 315 and at the same time the capacitor 305. ) And one end of the resistor 314. In addition, a reference voltage VCC is applied to a non-inverting terminal (+) of the operational amplifier 323 by a matching filter composed of resistors 320 and 321 and a capacitor 310.

Since the operational amplifier 323, the resistor 314, and the capacitor 305 are structures of a conventional amplifier, the amplified second sound source signal is then amplified by the capacitor 306 and the resistor 316 to the ninth node 9. Enter

The third sound source signal passing through the output terminal C of the sound source signal generator 20 is input to the inverting terminal (−) of the operational amplifier 324 through the capacitor 307 and the resistor 317 and at the same time the resistance ( 318 and one side of the capacitor 308, and the non-inverting terminal (+) of the operational amplifier 324 by the integral filter consisting of the resistors 320, 321, and capacitor 310, the constant reference voltage ( VCC) is applied. Since the operational amplifier 324, the resistor 318, and the capacitor 308 are structures of a conventional amplifier, the amplified third sound source signal is amplified by the capacitor 309 and the resistor 319 to the ninth node 9. Enter

Accordingly, the amplified first sound source signal, the second sound source signal, and the third sound source signal are converted into a waveform similar to the waveform of the waveform of the fluted sound, such as the waveform of FIG. 401 and the capacitor 408 are input to the integrating circuit.

The resistor 401, the capacitor 408, the resistor 402, the capacitor 409, the resistor 403, the capacitor 410, the resistor 404, and the capacitor 411 have a four-stage integral filter. Four-stage filtering of the square wave signal generated by the ninth node 9 is transformed into a sinusoidal signal such as the waveform of FIG. 2e, that is, an accurate flute negative waveform, and then input to the collector stage of the transistor 412. At this time, when the flute musical instrument sound is selected by a key (not shown) and the switch 413 connected to the base end of the transistor 412 is turned on, the voltage VCC is applied to the base of the transistor 412 through the resistor 406. This is applied. Accordingly, the sine wave signal input to the collector terminal of the transistor 412 is input to the mixing amplifier 50 through the emitter terminal and the output level adjusting resistors 405 and 407, and the mixing amplifier 50 corresponds to the input waveform. The flute sound is generated and output as an audible sound through the main amplifier 60 and the speaker 70.

As described above, the present invention increases the number of musical instruments to create a pulse wave similar to the flute sound, and inputs the pulse wave into a simple pulse means to generate a flute sound, thereby obtaining an accurate flute sound and simplifying the circuit configuration. There is an advantage to that.

Claims (3)

A flute tone generating circuit of an electronic keyboard having a mixing amplifier, a main amplifier, and a speaker, comprising: a microcomputer 10 for outputting data corresponding to a user's pressing of any key, and the data of the microcomputer 10; A sound source signal generator 20 for inputting and generating a first sound source signal, a second sound source signal, and a third sound source signal, which are divided at a predetermined ratio and output through the output terminals A, B, and C, respectively, and the sound source signal The square wave signal generator 30 and the square wave signal generator for amplifying the first sound source signal, the second sound source signal, and the third sound source signal of the generator 20 to synthesize a synthesized wave signal similar to a flute sound. Sine wave output by audible sound through the mixing amplifier, main amplifier and speaker when the flute sound is selected by the user after multi-stage filtering the standing wave signal of the minute 20 to generate a sine wave signal such as the waveform of the flute tone Generating flute tones of keyboard electronic circuitry, characterized by consisting of a number generator (40). The operational amplifier of claim 1, wherein the square wave signal generator 30 connects the first node 1 and the inverting terminal (-) and the power supply line 8 and the non-inverting terminal (+). 322, a second node 2 connecting the output terminal of the operational amplifier 322, and a capacitor connected in series between the output terminal A of the sound source signal generator 20 and the first node 1. 301 and a resistor 311 connected in series to the capacitor 301, a capacitor 302 connecting one end to the first node 1 and the other end to the second node 2, A resistor 312 connected in parallel with the capacitor 302, a capacitor 303 connected in series between the second node 2 and a ninth node 9, and a resistor connected in series with the capacitor 303 ( 313, an operational amplifier 323 for connecting the third node 3 to the inverting terminal (-) and a power supply line 8 and a non-inverting terminal (+), and an output terminal of the operational amplifier 323. To connect A capacitor 304 connected in series between the four node 4 and the output terminal B of the sound source signal generator 20 and the third node 3 and a resistor 315 connected in series with the capacitor 304. A capacitor 305 for connecting the third node 3 and one side end and connecting the fourth node 4 and the other end, a drop 314 connected in parallel with the capacitor 305, and A capacitor 306 connected in series between the fourth node 4 and a ninth node 9, a resistor 316 connected in series with the capacitor 306, a fifth node 5, and an inverting input terminal (-); And an operational amplifier 324 for connecting the power supply line 8 and a non-inverting terminal (+), and a sixth node 6 and a fifth node for connecting an output terminal of the operational amplifier 324. 5) and one end connected to the capacitor 308 for connecting the sixth node 6 and the other end, a resistor 318 connected in parallel to the capacitor 308, and the output terminal of the sound source signal generator 20 A capacitor 307 connected in series between (C) and the fifth node 5 and a resistor 317 connected in series with the capacitor 307, the sixth node 6 and the ninth node 9; A capacitor 309 connected in series between the capacitor 309 and a resistor 319 connected in series with the capacitor 309, a seventh node 7 connected with the power supply line 8, and the seventh node 7. A capacitor 310 connected in series between the ground and the ground, a resistor 320 connected in series between the seventh node 7 and the ground, and a series connected between the seventh node 7 and the power supply VCC. Flute tone generating circuit of the electronic keyboard, characterized in that consisting of a resistor (321). The resistor 401 according to claim 1, wherein the sinusoidal signal generator 40 constantly connects the ninth node 9 and one end thereof, and the resistor 401 connects the other end and one end thereof. 402, a resistor 403 for connecting the other side end and one side end of the resistor 402, a resistor 404 for connecting the other side end and one side end of the resistor 403, and the resistance 404 A transistor 412 connecting the other end and the collector end and connecting the tenth node 11 and the emitter end, a capacitor 408 connecting one end between the resistors 401 and 402, and the resistor; A capacitor 409 for connecting one end between 402 and 403, a capacitor 410 for connecting one end between the resistors 403 and 404, the resistor 404, and A capacitor 411 for connecting one end between the collector terminals of the transistor 412, and an opening / closing switch connected in series between the base terminal of the transistor 412 and the power supply VCC. 413 and a resistor 406 connected in series to the on / off switch 413, a resistor 407 connected in series between the tenth node 11, and the ground, and one side with the tenth node 11. A flute tone generating circuit of an electronic keyboard, characterized by comprising a resistor 405 for connecting a stage.