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 conventional voltage drive circuit, FIG. 2 is a
time chart showing the waveform of the main part thereof, and FIG. 3 is a voltage drive circuit
showing one embodiment of the present invention, FIG. FIG. 5 is a time chart showing the
waveform of the main part, FIG. 5 is a plan view of the piezoelectric ceramic attached to the
diaphragm, and FIG. 6 is an experimental curve showing the relationship between sound pressure
and frequency. ????????????????????????????? L2 ииииии Coil, P2
иииииии Piezoelectric element.
DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a voltage driving
circuit (for example, driving a piezoelectric element or the like). In the prior art, there was a
transistor circuit shown in FIG. 1 for driving a piezoelectric element. This is to drive the
piezoelectric element P1 by the reverse induction voltage generated in the transistor Tr (at the
trailing edge of the pulse signal of FIG. 2A supplied with K, that is, at the time of cutoff of the
transistor circuit). As shown in FIG. 2B, this waveform is an attenuation signal with a relatively
high frequency, so there is a disadvantage that a sound pressure can not be obtained so much. By
the way, if the number of turns of the coil L1 is increased, a low frequency can be obtained and
the sound pressure will be increased, but the space increases with the increase of the number of
turns, which is inconvenient for a device requiring miniaturization. In particular, when a
piezoelectric element is used as a buzzer for a small electronic alarm clock, the storage space of
the buzzer is limited, and the number of turns of the coil may not be increased as described
above. Also, although a transformer ? can be considered as a drive circuit, it is not desirable in
space. So the present invention is a diode in series with the coil VCIl! It is intended to provide a
voltage 1 # As circuit in which the required power is obtained with a coil having a small number
of turns. An embodiment of the present invention will be described below based on the drawings.
In FIG. 6, the pulse signal shown in FIG. 4 Al11 is supplied to the terminal a, and is applied to the
base of the transistor Tr0 through the resistor R. The transistor Tr, therefore, is switched and,
when it is off, is rectified by the diode d to produce the pulse of FIG. 4B. As clearly shown in the
waveform diagram of FIG. 4B, the driving force of the piezoelectric element P2 is increased and
the sound pressure is improved as compared with the conventional case. Hereinafter, the
comparison between the conventional voltage drive circuit shown in the first diagram and the
present embodiment will be described based on experimental data. FIG. 5 shows a plan view of a
diaphragm n on which a piezoelectric ceramic m to be tested is attached. Diaphragm n is SUS
material of diameter 1401 and thickness 01 ?, piezoelectric ceramic m is long side 10 m, short
side 2 fi, thickness 0.2 fi, coil L1 and L2 ki reduced diameter ?05 ?, number of turns 1400,
transistor It is a collector voltage Fitsv of Tr1-Tr2. Then, the diaphragm n is housed in the
resonance case, and the relationship between the sound pressure and the frequency of the pulse
applied to the transistor when measured in the A range at a point 10 cm @ is shown in FIG. In the
case of the present invention, A is the case of the drive circuit shown in FIG.
Clearly from this, the sound pressure of this embodiment is increased compared to FIG. 3-J) J
Although the transistor is used as the drive circuit in the above embodiment, the invention is not
limited to this and any switching means may be used. As described above, in the present
invention, since the output side of the drive circuit (the coil and the diode are connected and the
driven element such as the piezoelectric element is connected to this circuit in one row), the
driven element can be effectively driven. Since the number of turns of the coil is smaller than in
the prior art, it is advantageous when used as a small device, for example, as a sound generator
of an electronic alarm clock subject to space constraints.
Без категории
Размер файла
9 Кб
Пожаловаться на содержимое документа