вход по аккаунту



код для вставкиСкачать
Patent Translate
Powered by EPO and Google
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.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a wiring diagram of a conventional MFB
speaker device, FIG. 2 is a wiring diagram of the MFB speaker device of this invention, and FIG. 3
is a wiring diagram of a detection circuit. 1 is a pickup coil, 3 is a drive amplifier, and 4 is a level
setting circuit.
DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement
of a so-called MFB speaker apparatus having a speaker provided with a pinkup coil independent
of a drive coil and feeding back the pickup coil detection voltage to another speaker drive
amplifier. A conventional MFB speaker device will be described with reference to FIG. 1.
Reference numeral 1 denotes a pickup coil mechanically coupled to a drive coil 2, and the pickup
coil / 1-ρ P2 is the same as the drive coil / L / 2 It is disposed in the magnetic field or in an
independent magnetic field. The drive coil / L / 2 is vibrated by the audio signal from the drive
amplifier 3. As a result, a voltage corresponding to the vibration of the drive coil 2 is generated in
the pickup coil 1, and the voltage is fed back to the drive amplifier in reverse phase. It is intended
to electrically control the fo, Q, and amplitude of the speaker system from K, and to further
improve the nonlinear distortion including the vibration system. In order to detect the vibration
of the drive coil 2, various ones have been devised, such as one utilizing a change in capacitance
of a capacitor other than the pickup coil l, one that detects optically, and the like. Particularly in
the MFB nubeaker apparatus used for such purpose, focusing on the action of suppressing the
large amplitude operation, it is desirable that this action acts only during the large amplitude
operation. However, in the conventional MFB speaker device, since the suppression action always
works regardless of the magnitude of the amplitude, there is a drawback that the efficiency of the
speaker at the time of the small amplitude operation is significantly reduced. In order to solve the
above drawbacks, this invention works so that the amplitude suppression function works only
when the detection voltage of the pickup coil becomes larger than a predetermined value, that is,
when the amplitude of the drive coil becomes a predetermined value or more. The embodiment,
which is configured, will be described in detail below with reference to FIG. In FIG. 2, reference
numeral 3 denotes a drive amplifier, and the drive coil 2 is connected to the output thereof. On
the other hand, the detection voltage generated in the pink-up coil 1 is input to the level setting
circuit 4, and the detection voltage is fed back to the driving amplifier only when the voltage is
determined by the level setting circuit and is generated in the pink-up coil. Do the action. FIG. 8
shows an embodiment of the level setting circuit used in the present invention, and more
specifically, 11lr is a transistor having an emitter connected to the middle of the feedback circuit
between the pickup coil 1 and the amplifier and a collector connected to ground. . Further, the
detection voltage generated in the pickup coil 1 is converted into a direct current by a rectifying
and smoothing circuit comprising four diodes D1 and a capacitor C1, and is manually operated at
one terminal of the level comparator L1.
On the other hand, the set voltage stabilized by the zener diode z1 and selected by the variable
resistor VR is inputted to the other terminal of the level comparator. Then, the output of the level
comparator is input to the base of the transistor. However, when the voltage 1-character
insertion generated in the Mypin coil 1 is lower than the level set in VR, the level / comparator is
positive, and the output of the positive 9 transistor TR conducts to short the feedback circuit.
Pick Anoff. The detection voltage of the coil 1 is not fed back to the drive amplifier and does not
perform the MFB operation. On the other hand, when the detection voltage of the pickup coil 1 is
larger than the set level, the output becomes O and the transistor TR is cut off. The voltage
generated in the pickup coil 1 is fed back to the drive amplifier 3 via the feedback circuit and one
or more of the MFB operations are performed as described above, this invention feeds the
detection voltage of the big anno 5 coil 1 back to the drive amplifier 8 In the MFB speaker device
in which the large amplitude operation of the drive coil 2 is suppressed, the detection voltage of
the pickup coil 1 is fed back to the drive amplifier via the level setting circuit 4 and the detection
voltage is a predetermined value or more In the case of large amplitude operation only when
Foot drop in those prevention is made practical value large because it is as well as a very useful
and easy Naru circuitry.
Без категории
Размер файла
9 Кб
Пожаловаться на содержимое документа