CN2036694U

CN2036694U - Electronic simulated piano

Info

Publication number: CN2036694U
Application number: CN 88209532
Authority: CN
Inventors: 吴宁
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-08-10
Filing date: 1988-08-10
Publication date: 1989-04-26

Abstract

The utility model belongs to an electronic keyboard musical instrument. Based on the basic structure of a common electronic organ, each key is provided with a capacitance pressure transducer and a capacitance tone variation control circuit thereof, so that the utility model can decide the sizes of the sound volume according to the strength of a player pressing keys, to vividly imitate a piano effect, can create tone variations of the piano tone colors and changing sound volume tone colors varying from time to time with the pressure change of finger pressing keys, and start a new field for electronic organ expressive force. The utility model has the advantages of simple structure and low cost.

Description

Electronic simulated piano

The utility model belongs to electric keyboard instrument.

Keyboard electronic organ is present very popular novel musical instrument, it has the function of the tone color of the multiple musical instrument of imitation, and it is easy to carry, moderate, be subjected to consumers in general's favor, commercially available mellotron can imitate remarkably true to lifely to the tone color of piano at present, but bullet does not go out the effect of real piano, because piano can send strong and weak different sound along with the weight that the player points button, reach the processing of the exquisiteness that the melody emotion is changed, and the singly-bound volume of now commercially available keyboard electronic organ can not change.Though also utilize the key control light path, with the time interval of light-receiving device detection signal, or change with volume behind the conductive rubber pressurized, cause contact resistance to change or the like method and detect keystroke intensity, but too complexity or price exceed the piano price far away and do not have practical significance because of structure eventually.Up to the present also there is not a kind of similar mellotron to reach practical and commodity stage in a word.

The purpose of this utility model is to remedy the deficiency of existing mellotron, and design a kind of simple in structure, the keyboard electronic organ of being convenient to promote, it has makes each key point the weight of chain shot along with the player and sends the function of different strong and weak volumes, and structure is very simple, and production cost is very low.Thereby make its playing effect reach the degree that matches in excellence or beauty with piano, and price have only the part of piano.And create the electric organ effect that can eject strong and weak sound.

The purpose of this utility model realizes by following technical scheme, at the existing oscillatory circuit of mellotron, on the basis of frequency dividing circuit, tone color circuit, cycling circuit and amplifying circuit, set up the strong and weak sound control system circuit of condenser type, and on each qin is strong, installed capacitance pressure transducer, additional, wherein the strong and weak sound control system circuit of condenser type includes by IC ₁, IC ₂The public pulse producer that constitutes is by IC ₃The condenser type pulse duty factor regulating circuit that constitutes is by A ₁The differential type filtering output circuit that constitutes is by IC ₁, A ₂, IC ₄The sampling hold circuit of forming is by TG ₂, IC ₉, TG ₃And public switch Kc ₁, Kc ₂The figure control circuit of forming and by R, D ₁, D ₂The voltage-controlled analog switching circuit of forming is formed.Capacitance pressure transducer, is by contact electrode, electric capacity moving plate and capacitor fixed plate are formed, contact electrode is fixed on the lower surface of key, one end and circuit join, the electric capacity moving plate is the metal plate that an end is bow type convex, be positioned at the key below, the intermediate portion is stained with conductive rubber corresponding to the place of contact electrode, capacitor fixed plate be one be positioned at electric capacity moving plate below and with the metal plate of its opposing parallel, it directly is printed on the printed circuit board (PCB) with circuit, its surface partly covers one deck dielectric film corresponding to the electric capacity moving plate, and the stiff end of electric capacity moving plate and key all is connected with printed circuit board (PCB) with trip bolt.

Principle of work of the present utility model is as follows: when the player with different strength keystrokes, when key is pressed with certain speed, contact electrode at first surface in contact has the electric capacity moving plate of conductive rubber, the circuit of this sound is connected, just oppressing the electric capacity moving plate at this when key continues to move downward in a flash also moves downward, the electric capacity of capacitive transducer is changed, by condenser type pulse duty factor regulating circuit and differential type filtering output circuit, be transformed into voltage signal, and sample in certain moment that the circuit of this sound is connected, and this voltage signal is remained on the sampling capacitance by sampling hold circuit.Determine that through the figure control circuit this signal voltage is the minor of piano or the long that has fallen with key, control voltage-controlled analog switching circuit by this signal voltage at last, to controlling to the transmission of tone color circuit and amplifier by the sound signal of frequency divider output.To reach the purpose of controlling the volume of this sound according to the finger keystroke weight.When this control signal voltage during, also can produce the amount of the changing voice tone color that volume changes at any time with finger key press size without sampling hold circuit.

1. condenser type pulse duty factor regulating circuit and differential type filtering output circuit.At first by two monostable circuit IC ₁, IC ₂The public pulse producer of forming produces the high-frequency pulse signal of hundreds of kilohertz, is used for the accurate monostable circuit IC of continuous trigger ₃, IC ₃Timing capacitor be capacitive transducer CT, when the sensor attonity, regulate the square wave of monostable output symmetry, when sensor capacitance increases, make the dutycycle of the output square wave formation condenser type duty cycle adjustment circuit that changes.Circuit changes two opposite row square waves from Q and Q output, and after differential filtering, the difference input is connected into the operational amplifier A of differential amplifier ₁, detect the direct current output linear with pulse duty factor.

2. sampling hold circuit.Be contained in the contact electrode above the capacitive transducer, promptly key switch KT is connected on the pull-up resistor, and ground connection when it is closed produces a negative saltus step, and this negative jumping is directly triggered monostable circuit IC ₄Make its positive pulse that produces a certain width, this positive pulse goes control by analog switch TG again ₁, sampling capacitance C and high input impedance operational amplifier A ₂The sampling hold circuit of forming is once sampled to the DC voltage formation of differential type filtering output circuit output, and this voltage is remained on the sampling capacitance C.

3. voltage-controlled analog switching circuit and figure control circuit.Work as TG ₂D when closing ₁And D ₂Be mutual reversal connection, the sound signal Vi of frequency divider output is intransitable, works as TG ₂Open A ₂Directly export the voltage on the sampling capacitance C and pass through TG ₂On resistance R, produce a corresponding pressure drop, because D ₁Be forward conduction at this moment, so at D ₁Negative pole just produce one and change amplitude and TG with Vi ₂The proportional electric signal of level of the sampling hold circuit output of passing through, and pass through D ₂Outwards output.So just formed by signal output power and the break-make of frequency divider, all by TG to next stage tone color circuit ₂The simulation pressuring controling switch circuit of output control.

1. when Kc is connected into the piano figure, IC ₄The rising edge of a pulse of the sampling that produces of Q when finishing trigger monostable circuit IC again ₅, make it produce a positive pulse, control analog switch TG ₂A level and the linear potential pulse of keystroke moment sensor capacitance are let slip in conducting, have so just obtained piano sound certain volume, short.

2. when Kc is connected on the organ figure, TG ₃Just become the phase inverter of key KT, the level after anti-phase is connected on TG by diode ₂Control extremely go up TG ₂Be opened, the level of sampling hold circuit output directly passes through.It is relevant with the speed of this sound keystroke moment so just to have obtained volume, and keeps this volume constant, with the long that key has fallen beginning and finished, can change strong and weak organ sound.

3. when Kc is connected on the amount of the changing voice figure, TG ₁The control utmost point, be connected on the positive voltage TG by diode ₁Often open, this just is equivalent to sampling hold circuit by short circuit, presses key TG this moment ₂Be opened A ₁The level of output directly passes through, and so just forms and changes the pressure that finger is pressed key, the amount of the changing voice tone color that volume can change thereupon in the phonation.

The utility model has the advantages that: load onto capacitance pressure transducer, for each key, make it can decide the volume of this sound according to the weight of the person's of playing the musical instrument finger keystroke.

When 1. playing, can send strong and weak different sound according to the size of finger keystroke strength with the piano figure, and with piano equally whenever by key both just hand do not lift, also can only send the piano sound of a weak point.The imitation piano effect that so just can be really true to life, thus might fundamentally replace cost an arm and a leg, complicated, heavy piano.

When 2. playing with the organ figure, can create the strong and weak sound organ sound that makes new advances, promptly be as the criterion with finger keystroke moment weight, send the sound of respective output volume, even do not change as long as finger does not lift the pressure of hand key, volume also no longer changes, thereby can play easily, makes the expressiveness of organ tone color fine and smooth more.

3. can produce a kind of amount of changing voice tone color, promptly in the process of each sound pronunciation, change the pressure that finger is pressed key, the volume of sending be changed, the paradoxical effect of the volume that changes thereupon.

4. all tone colors and original all functions of keeping the constant power of primary electron qin.

5. circuit structure is simple, reliable, cost is low, is convenient to promote.

Description of drawings:

Fig. 1 is the key structural drawing that capacitive transducer is housed

Wherein: the 1-key; The 2-contact electrode; 3-electric capacity moving plate; The 4-capacitor fixed plate; The 5-conductive rubber; The 6-printed circuit board (PCB).

Fig. 2 is a schematic block circuit diagram of the present utility model:

Wherein: the 7-oscillatory circuit; The 8-frequency dividing circuit; 9-tone color circuit; The 10-cycling circuit; The 11-amplifying circuit; The public pulse producer of the strong and weak sound control system circuit of 12-condenser type; The strong and weak sound control system circuit of 13-condenser type; 14-is equipped with the key of capacitance pressure transducer.

Fig. 3 is the circuit theory diagrams of the strong and weak sound control system circuit of condenser type.

Embodiment:

In the concrete structure of Fig. 3, IC ₁～IC ₅Be 1/2CD4538A ₁, A ₂ Be 1/4LF347, TG ₁～TG ₃Be 1/3CD4053.This mellotron is when playing, and the piano effect is true to nature, and soft and stress tone is obvious, and circuit working is reliable.

Claims

1, a kind of artificial electronic piano, form by key and circuit part, circuit part comprises oscillatory circuit, frequency dividing circuit, tone color circuit, cycling circuit and amplifying circuit, it is characterized in that circuit part set up the strong and weak sound control system circuit of condenser type, and partly installed capacitance pressure transducer, at key: wherein condenser type power sound control system circuit includes IC ₁, IC ₂The public pulse producer that constitutes is by IC ₃The condenser type pulse duty factor regulating circuit that constitutes is by A ₁The differential type filtering output circuit that constitutes is by TC ₁, A ₂IC ₄The sampling hold circuit of forming is by TG ₂, IC ₅, TG ₃And public switch Kc ₁, Kc ₂The figure control circuit of forming and by R, D ₁, D ₂The voltage-controlled analog switching circuit of forming; Capacitance pressure transducer, is by contact electrode, electric capacity moving plate and capacitor fixed plate are formed, contact electrode is fixed on the lower surface of key, one end and circuit join, the electric capacity moving plate is the metal plate that an end is bow type convex, is positioned at the key below, and the intermediate portion is stained with conductive rubber corresponding to the place of contact electrode, capacitor fixed plate be one be positioned at electric capacity moving plate below and with the metal plate of its opposing parallel, its surface coverage one deck dielectric film.

2, mellotron according to claim 1 is characterized in that capacitor fixed plate is directly to be printed on the printed circuit board (PCB) with circuit.