CN87209532U

CN87209532U - Qin with self-suiting function

Info

Publication number: CN87209532U
Application number: CN 87209532
Authority: CN
Inventors: 陈学煌
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-06-23
Filing date: 1987-06-23
Publication date: 1988-06-29

Abstract

The utility model relates to a musical instrument with a self-suiting function. Changing impedance components are arranged in an amplitude separation circuit and a filter of the utility model. The changing impedance components are controlled by voltage relating to the frequency of input signals so that the constants of a separator and the filter are automatically adapted to the input signals. As a result, the reliability of the separation circuit is further increased.

Description

Qin with self-suiting function

Application number be 86205521,86207013 Chinese patent application provided utilize that amplitude separates, the music apparatus of synthesis type fundamental detection device and phase-locked converter technique.This device has realized using the function of song " bullet " qin with low cost, but following shortcoming is arranged still, promptly in whole operating frequency range, be difficult to guarantee the unanimity of detection accuracy, its reason is, the amplitude separation circuit of this device has adopted the regular time constant, and in fact for this constant of different frequencies corresponding optimum value is arranged all.When the frequency range broad, perhaps when the singing voice signals of input because the change of chanteur's sound channel or other are former thereby when being subjected to amplitude modulation(PAM), this shortcoming is just more obvious.Thereby must be overcome.

The objective of the invention is to, a kind of adaptive technique is provided,, promptly further improve the accuracy of fundamental detection part and adaptive faculty different chanteurs still keeping cheaply under the situation above-mentioned deficiency being improved.

Here so-called adaptive technique refers to that the time constant of above-mentioned separation vessel can become with frequency input signal automatically, also can make separation vessel filter constants before do corresponding variation simultaneously, to reach better effect.Be illustrated below in conjunction with accompanying drawing.

Voluntary musical instrument has two kinds of mode of operations, and accompanying drawing 1a and b have provided the block diagram (being designated hereinafter simply as I, II type qin) of two kinds of patterns respectively.(1) is sonic transducer among the figure; (2) be amplification, wave filter; (4) be storbing gate, it is subjected to the control of amplitude discriminator (3); (5) be fundamental detection device (reshaper); (6) be the tone color processor; (7) be the rhythm sound generator; (8) be amplifier; (9) be loudspeaker; (10) be phaselocked loop; (11) be sampling switch; (12) be controlled switch device group; (13) be the standard temperament generator; (14) be keyboard.Wherein main circuit is seen application case 86205521, No. 86207013.I type qin utilize phaselocked loop doubly, division function and attached with Sampling techniques, qin is sent and the consistent or harmonious musical sound of sound person's pitch, II type qin then makes the work of a standard temperament generator by phase-locked converter technique, makes qin send the standard musical sound close with the sounder pitch.Two kinds of patterns (the particularly latter) are all more convenient when increasing this adaptive technique, this be because, they have all used phase lock circuitry to remove to follow the tracks of input signal, and the low-pass filter output terminal of phaselocked loop will obtain one with the linear substantially voltage of frequency input signal, this voltage promptly can be used as above-mentioned separation vessel of change and filter time constant usefulness, needn't increase new circuit again.

Changing time constant can realize that generally the former is more convenient by the resistance or the electric capacity that change in the circuit, particularly in the occasion of continuous variable.Many devices (as crystal two utmost points, triode) with thyrite characteristic all can be used herein.Accompanying drawing 2a and b provide two embodiment wherein, and Fig. 2 a increases by one group at the base loop of separator tube and simulates switch, incorporate at the resistance that different frequency ranges is suitable with this frequency range, to reach the purpose that changes time constant.The time constant of separation circuit is selected in 2～8 times of fundamental frequency cycles to well, and the switches set number can determine according to the range scope, when range during at 100～1000HZ optional 2～4, practical function is preferably arranged promptly, and is The more the better certainly, but cost has also increased.The control of switch is convenient especially to II type qin, need only draw high level signal from the appropriate location of former comparator bank and get final product, and I type qin then must be established several comparers in addition.

Fig. 2 b replaces fixed resistance with the voltage adjustable resistance, and T21 is the phase-splitting pipe, for T22 and T23 provide suitable excitation.T22 and T23 are respectively N ditch and P ditch technotron, are used as the voltage adjustable resistance here, are designated as RT.Control voltage takes out from the low-pass filter output terminal of phase locking converter, is connected to the W21 upper end through a follower.T22 and T23 should match, and regulate W21 and RA, RB and satisfy following requirement, i.e. RTC=(2-8 when making the highest and low-limit frequency) T, (T is an input signal cycle in the formula) then other Frequency point promptly satisfies automatically.

After adopting above-mentioned self-adaptation separation circuit, exponential amplifier just can be cancelled thereby cost does not increase in the original application case.Equally, will control voltage and introduce in the wave filter, change filter constants, then constitute sef-adapting filter.To RC wave filter commonly used, comparatively make things convenient for Fig. 3 to provide a kind of method that second-order low-pass filter is changed into sef-adapting filter to change R, promptly with the linear resistance in the voltage adjustable resistance replacement general filter, the pass-band performance of wave filter is changed with frequency input signal, press the connection among the figure, when control voltage raises (being equivalent to frequency increases), field effect transistor T11 and T12 internal resistance reduce, the wave filter corner frequency rises, and adapts with input signal.T11 and T12 characteristic should be consistent, and make by their signal level in hundreds of millivolts.The inverting input of comparer A and a fixed voltage E connect, E is control corresponding voltage during a little less than low-limit frequency, thereby A output low level at ordinary times, and K disconnects, the corner frequency of wave filter is decided by the mid-point voltage of potentiometer W, and the turning point that makes of adjusting is in the upper limit of frequency range.

Also availablely simulate switch and linear resistance, hold and do segmentation and follow the tracks of, exemplify no longer one by one.

In the ordinary course of things, self-adaptation separation vessel and sef-adapting filter only use one of them to get final product, and adopt better effects if simultaneously, and cost slightly increases.

Accompanying drawing 1 is that the circuit block diagram of formula is touched in two kinds of work.

Accompanying drawing 2 is the embodiment circuit diagram of self-adaptation separation vessel.

Accompanying drawing 3 is the embodiment circuit diagram of sef-adapting filter.

Claims

1, a kind of mellotron, by sonic transducer, amplifier, wave filter, with the positive and negative half cycle of the signal amplitude of carrying out separate, synthetic fundamental frequency detector, phase locking converter, tone color processor (or adding the standard temperament generator), compositions such as rhythm sound generator, loudspeaker, it is characterized in that: the time constant of this wave filter or amplitude separator is subjected to the control of frequency input signal.The Control of Voltage relevant with frequency input signal the thyrite device or simulated switch and then the time constant of above-mentioned wave filter or amplitude separator is changed.

2, according to the described mellotron of claim 1, it is characterized in that: the amplitude separator time constant is selected in 2～8 times of fundamental frequency cycles scopes.