JPS5925231B2 - Chord storage device in electronic musical instruments - Google Patents

Description

[Detailed description of the invention] The present invention relates to a chord storage device for an electronic musical instrument.

Conventionally, in this type of device, a separate reset switch was operated to clear the stored code.

This reset switch, like other operation switches, is generally installed on a channel remote from the keyboard.
This often caused problems with performances. It is an object of the present invention to provide a chord storage device that does not cause any hindrance to such musical performance. A plurality of semiconductor elements are installed together, and each control electrode is connected to a discharge circuit and a capacitor that is charged by pressing a key and makes the semiconductor element conductive with a charging voltage. A noise generator is connected to the output terminal of the sound source signal and generates a pulse at the moment a key is pressed, and the output pulse instantaneously closes each of the discharge circuits and instantly discharges the capacitor. in which each of the discharge circuits is activated by the output signal of the detection circuit which detects when two or more keys are pressed simultaneously and generates an output signal while the keys are being pressed. It is characterized by a closed circuit.

A second aspect of the present invention is that in the first aspect, when two keys are released from being pressed at different times in the detection circuit, charging is started when one key is released from being pressed, and operation is started with the predetermined charging. The present invention is characterized in that an auxiliary circuit is provided, and the operation of the auxiliary circuit maintains the closed circuit of each of the discharge circuits.

Next, an example of the implementation of the present invention will be described with reference to the attached drawings.

In the drawings, 1-1, 1-2, . . . indicate semiconductor devices having control electrodes 1a-1, 1a-2, . -1,1
-2... consists of, for example, an FET, whose control electrodes 1a21, 1a-2..., i.e., gate electrodes are connected via key switches 2-1, 2-2, respectively. and connect it to one pole 3a of the power supply, and connect the capacitors 4-1, 4
-2... were connected to the other pole 3b of the power supply via each terminal.

2a-1, 2a-2... are the key switches 2
Key switches 2a-1, 2-2, . . . are arranged in parallel.
* is connected in common to the negative power supply 5a through the respective resistors 6, and to the earth power supply 5b (positive) through the common resistor 7.

A differentiating circuit 9 and a diode 10 are connected to the common connection point 8.
The output terminal is connected to a common discharge circuit 15 for each capacitor 4-1, 4-2, . The control electrode 16a of the transistor 16, which is a switching element, is connected to the control electrode 16a. A common discharge circuit 15 connects the capacitors 4 to 4 through respective diodes 17.
Control electrode 1a-1, connected to 1, 4-2...
Connected to 1a-2... Each semiconductor element 1-1
, 1-2..., each input electrode, that is, the source electrode 1b
-1, 1b-2, . . . are connected to output terminals for a plurality of sound source signals corresponding to the code. 18 indicates a signal separation resistor inserted in the connection circuit 0 and its output electrode 1c-
1, 1c-2, . . . are connected in common and connected to a speaker 21 via a rhythm gate circuit 19 and an amplifier 20, which are opened by the output signal of the rhythm pulse generator.

Thus, if you press the key now, the key switch 2-1, 2a-1
When closed, a reset pulse is generated from the pulse generation circuit 11, which turns the first transistor 12 ON and the second transistor 13 OFF. When placed at a potential, the switching element 16 becomes conductive and connects each capacitor 4-1, 4-2, 4-2 through a diode 17, respectively.
... is placed in a closed circuit and is instantaneously discharged.

Then, when the set pulse disappears, the first transistor 12 becomes 0FF1, the second transistor 13 becomes 0N, and the switching element 16 becomes 0FF. Thus, the capacitor 4-1 is charged via the key switch 2-1, the semiconductor element 1-1 becomes conductive, a plurality of sound source signals C, E, and G pass through it simultaneously, and the rhythm gate 19 is opened by the rhythm pulse. As a result, a C major rhythm sound can be obtained from the speaker 21. Since the input impedance of the control electrode 1a-1 of the semiconductor element 1-1 is high, the capacitor 4-1 is not easily discharged and maintains its charged state for a long time, and the rhythm sound is Continue to occur. Next, when the key switches 2-2 and 2a-2 are closed, a reset pulse is generated as described above, the switching element 16 becomes conductive, and the capacitor 4-1 is instantaneously discharged.

Subsequently, the capacitor 4-2 is connected via the cow-switch 2-2.
is charged, conduction is provided to the semiconductor element 1-2, and a C-minor rhythm sound is obtained. In this way, by momentarily pressing each key, the previous memory is cleared and a new memory is stored, automatically producing a rhythm sound.

In addition, the above describes the key switches 2a-1, 2a- for generating reset pulses, which are connected to the capacitors 4-1, 4-2, 2-1, 2-2, . 2...
. . . are provided separately, but these key switches 2-1, 2-2 . . . , 2a-1
, 2a-2, . . . can be shared by connecting them as shown in FIG.

In FIG. 1, 22 indicates a detection circuit that detects when two or more key switches are closed at the same time, and upon this detection, each capacitor 4-1, 4-2, etc. I placed it in such a way that all memories were released.

The detection circuit 22 includes key switches 2a-1, 2a-2...
The Zener diode 23, the first and second transistors 24, 25, and the collector of the second transistor 25 connected to the common connection point 8 of the switching element 16 are connected to the control electrode 1 of the switching element 16.
6a and a diode 26 inserted into the circuit. Thus, when two or more key switches 2a-1, 2a-2, . The control electrode 16a of the switching element 16 is connected to the negative power supply -B through the diode 26, so that the switching element 16 is conductive, and each capacitor 4-
1, 4-2, . . . are placed in the discharge circuit 15 to put the respective semiconductor elements 1-1, 1-2, . 1,2-
2..., 2a-1, 2a-2...... When the circuit is opened, which capacitor 4-1, 4-2...
Since the battery is not charged, the rhythm performance is stopped. These key switches 2-1, 2-2...
22a-1, 2a-2, . . . are opened when the key is released, but they cannot be opened completely at the same time.

Therefore, there is a risk that charging will occur through the first switch which is opened later, and an unexpected code may be stored. Therefore, in order to prevent this, the auxiliary circuit 28 was provided. The auxiliary circuit 28 consists of a capacitor 29 connected to the collector of the first transistor 24 and the second transistor 25. Thus, when the first transistor 24 is conductive, the capacitor 29 is closed via the transistor 24. When the other key switch is opened and only one of them remains closed, the first transistor 24 becomes OFF, the capacitor 29 starts charging and its potential reaches a predetermined level. The second transistor 25 maintains 0FF until the value is reached.

Thus, by releasing two or more keys at the same time and setting the time constant to a value commensurate with the time difference between opening of each key switch, memorization is prevented.
As described above, according to the present invention, the code storage circuit is configured with a simple circuit, and the memory can be erased by pressing two or more keys at the same time without providing a separate reset switch. Even if two keys are released from being pressed at different times, it is possible to completely erase the memory without starting the memory.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of one embodiment of the present invention, and FIG. 2 is a circuit diagram of another embodiment. 1-1, 1-2... Semiconductor element, 1a-1,,
1a2... Control electrode, 2-1, 2-2...
..., 2a-1, 2a-2...morning switch,
4-1, 4-2... Capacitor, 11...
...Pulse generator, 15...Discharge circuit, 22.
...Detection circuit, 28...Auxiliary circuit.

Claims (1)

[Claims] 1. FET having a control electrode with high input impedance
A plurality of semiconductor elements for opening and closing musical sound signal output circuits such as the above are installed together, and each control electrode is connected to a discharge circuit and a capacitor that is charged by pressing a key and makes the semiconductor element conductive with the charging voltage, and the input of each semiconductor element is connected to a discharge circuit. A plurality of sound source signal output terminals corresponding to the code are connected to the electrodes, and a pulse generator is provided that generates a pulse at the moment a key is pressed, and the output pulse instantaneously closes each of the discharge circuits and causes the capacitor to close. In a device designed to cause instantaneous discharge, a detection circuit is provided that detects when two or more keys are pressed at the same time and generates an output signal while the keys are being pressed, and the output signal of the detection circuit is used to control each of the discharge circuits. A chord storage device for an electronic musical instrument, characterized in that the circuit is closed while two or more keys are pressed. 2. The detection circuit is provided with an auxiliary circuit that, when two keys are released from being pressed at different times, starts charging when one key is released and starts operating at a predetermined level of charging. 2. The chord storage device for an electronic musical instrument according to claim 1, wherein each discharge circuit is maintained closed until the circuit is activated.