Patent Translate Powered by EPO and Google Notice This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate, complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or financial decisions, should not be based on machine-translation output. DESCRIPTION JPS56103592 Description 1 and title of the Invention Loudspeaker Drive Method In a drive circuit for constant current drive of an electrodynamic speaker, among signals supplied to the constant current amplifier. A speaker drive system characterized by suppressing a signal of the lowest resonance frequency of the speaker or a frequency near the same. 2, the scope of claims The present invention relates to a speaker drive system. Conventionally, constant-current drive of an electrodynamic speaker. When the same driving power as other frequencies is driven by the speaker's mechanical impedance becoming minimum at or near the lowest resonance frequency. The energy radiated from the speaker becomes f more than necessary. Therefore, relying on the constant voltage drive, short-circuit the back electromotive force generated in the voice coil of the speaker with the relatively low internal impedance of the constant voltage amplifier, and consume the energy with the resistance of the voice coil to make the braking by K Put on, hold down the resonance sieve. However, in this constant voltage drive, the speaker with a large power coefficient to overpower the electroacoustic conversion efficiency of the speaker is overquenched and the lowest resonance frequency a, or-the oppositely radiated energy is In addition, when the speaker is driven by an amplifier that can obtain an output of dog discipline power, the temperature of the voice coil rises at large input, and its resistance value is 1.5 to 2 at a normal temperature. It doubles. In this case, there is a disadvantage that even if the human power is increased, the output does not increase in proportion to that. The present invention suppresses the resonance sieve generated on the frequency characteristic when driving the speaker in constant current by selectively suppressing the input signal in the circuit before the constant current amplifier, thereby solving the above-mentioned conventional drawbacks. It is The present invention will be specifically described below according to an embodiment shown in the 07-05-2019 1 drawings. FIG. 1 is an equivalent circuit in the case where an electrodynamic speaker is incorporated in a path reflex EndPage: 1 cabinet. 1 is a constant flow flow source work. And its internal resistance R0 is infinite. 2 is the resistance R of the voice coil of the speaker. ???? 3 is an electroacoustic conversion mechanism, and its force coefficient is taken as no. Here, B is the air gap magnetic flux density, and ? is the effective total length of the voice coil. 4 is the mass m of the mechanical system, including the one in which the inertance of the acoustic system is replaced by the mechanical system. Reference numeral 5 is a resistance r which is replaced by a mechanical system and a mechanical system. ?????????????????? Reference numeral 7 is a stiffness S 'obtained by replacing the stiffness of the acoustic system of the cabinet with a mechanical system. 8 is a mass m o obtained by replacing the inertance of the acoustic system of the boat with a mechanical system. Here, the target frequency range is limited to the bass range, and the elements of the electrical system are also replaced by mechanical systems. The equivalent circuit is as shown in FIG. Here, 9 is a system in which the constant current source of the electrical system is replaced with a mechanical system, and is an oscillating force BJIo. Resistor 5 'is one mechanical system resistance r. (1) Because it is the sum r of the resistance replaced with the mechanical system and the electrical internal resistance of the steady flow source is RQ first. и (1) rO = R, + R, "", but in this case, in Equation (1), Ro is infinite, and Q and B have finite sizes, so the right side of Formula 1 (1) The term is zero and ro = r. P and poS ?-jkr the sound pressure at a point where the distance from the speaker is r. p = -aeIIJwv ++++++++++++++++ (2) и 2?r. Where ?. Is the density of the medium, S is the effective radiation area of the loudspeaker diaphragm, 2? / ?, and ? is the wavelength. W is the angular frequency, and V is the degree of bundle of the moving plate of the speaker. Here, formula (3) is derived from the equivalent circuit of FIG. On the way, if the angular frequency at the lowest resonance frequency is ? and j (3) is substituted into the equation (2), then ? 6 Sa-jkr и и и и и и иииииииииииииииииииииииииииииииииииииии (4) 2?r equation (4) and there is no rise in frequency characteristics, however, the value of Q is generally (more than 15 and approximately 1 eg 5 Is the value of Thus, in the case of the thick v4 in Q, in the case of the bass reflex system, the radiated energy from the diaphragm is excessive at one frequency below and above the lowest resonance frequency. In the case of the closed system, the radiation energy becomes excessive at the lowest resonance frequency when the speaker is housed in the cabinet. Anyway, these things are not preferable. Therefore, if it is busy to call the value of "Qwa as Q, Q", the sound pressure P will be obtained if it could be realized. Next, the ratio T between P ? and P is determined. ???????? Therefore, if it is possible to realize a circuit having the transfer function of equation +6), the frequency characteristic of equation (5) can be equivalently obtained by constant-current driving the speaker having the frequency characteristic of equation (4) through the circuit. Become. The frequency a characteristic of equation (6) can be realized, for example, by the suppression circuit shown in FIG. EndPage: 2 Here,% 10 is a resistance R5, which is selected as a value represented by Formula (8). 11 is a resistor R2 and its value is arbitrary. 12 is an inductance L, and its value is according to equation (9). 13 is a capacitance C, 07-05-2019 2 and its value is ? K K. The reference numeral 14 denotes an inductance L2, the value thereof is given by the equation [11] [Y 15 is the capacitance C2, and the value thereof is given by the equation .12 JK. Of =-C + ... и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и и ииииииииииииииииииииииииииииииииииииииииииииииииииииииииииииииииииииииииииииииииииииииии ииииииииииииииииииииииииииииииииииииииииииииииииииииииииииииииииииииииииииииииииииииииии и и и и и и и и и и и и и и и и и и и и и Note here that the impedance when looking left from terminals 16. The impedance when looking at the right from .19 is assumed to be infinite. The circuit of FIG. 3 is composed of passive elements. Even if the configuration including the active element is 0, FIG. 4 shows an example of the entire configuration of the present invention. Here, 20 is a constant (pressure source, 2 is a constant current amplifier, and 22 is a speaker housed in a bus reflex type cabinet. Here, the constant voltage source 2o and the constant current amplifier 21 are connected directly to give frequency selectivity to the internal feedback circuit of the constant current amplifier, and the constant current amplifier itself is given the same transfer function as the circuit of FIG. You-. The above described the speaker housed in the bass reflex type cabinet, but for the speaker housed in the closed type cabinet, FIG. 1 and FIG. 2 9 (3), (4) e (5) t (5) 7) And for the ceremony, mz ?~. Also in the case of the speakers housed in the cabinet other than the bass reflex type and the closed type, if it is possible to form a pneumatic circuit having the same frequency characteristics as the heart admittance frequency characteristics of the speaker in each case, regardless of the speaker system The method of this example can be applied. As described above, according to the present invention, the speaker is driven at a constant current, and before the constant current amplifier, the input signal is frequency-selectively suppressed to be equivalent to or more than the constant pressure drive. The voice coil is raised in temperature by the input, and even if the resistance value is increased, the output is proportional to the input, regardless of its effect. 4. Brief description of the drawings Fig. 1 is an electrical and mechanical Q equivalent circuit diagram of a speaker housed in a bass reflex cabinet, and Fig. 2 is a mechanical equivalent of a loudspeaker with a bass reflex cabinet Kf3. circuit diagram. The first is a circuit diagram of the suppression circuit of the speaker drive system according to the present invention, and FIG. 4 is a circuit diagram showing an example of the entire configuration of the present invention. 1: constant current source, 2: voice coil resistance, 3: electroacoustic conversion mechanism, 4: mass, 5: mechanical resistance, 6; speaker stiffness, 7: cabinet stiffness, 8: boat mass. Attorney Attorney Attorney 1) Ri 2 Yuki 'EndPage: ? 07-05-2019 3

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